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Testing for a bad head gasket - Gas Analyzer vs Chemical
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- čas přidán 12. 08. 2024
- Is the chemical test kit Uview 560000 Combustion Leak Detector as accurate as a gas analyzer? In this video I will compare the two and discuss the variables associated with each test.
Engine Performance Diagnostics chapter 1 pg 13
Tests shown
- how to test for a bad head gasket using a gas analyzer
- how to test for a bad head gasket using a chemical kit
- how to test the fluid in a chemical kit for accuracy
- visual inspection methods to ID head gasket failures
Symptoms
- rough idle, misfire on start up
- loss of coolant
- white smoke from exhaust
- check engine light with misfire codes
Tools used:
- Uview 560000 Combustion Leak Detector Kit
www.jbtoolsales.com/uview-560...
- www.amazon.com/shop/scannerda...
Related videos
- How to test for a bad head gasket (chemical test)
• How to test for a bad ...
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• How to test for a bad ...
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Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.
The trick to the fluid tester is to have the engine warm and the thermostat open so the coolant flows. Then leave only about an inch or 2 of headspace. Good fluid will change color with the % of CO2 in the bubbles in the coolant that contaminates the free air in the coolant system. It turns from green to yellow, green is a small leak, yellow is a large leak for gasoline engines. The tool is designed to catch an early head leak that otherwise is not very obvious. If the cyl is dead, then there are other ways to find that the coolant is in the cyl in question. I agree the sniffer is much better, but the chemo test is a cheap handy tool to eliminate a possible cause for an issue IF the cyl is still mostly firing ok. I've avoided buying a couple used trucks by using this chemo test, when the trucks seem to run perfectly well but OOPS... the test turned green, or greenish yellow. Often is a simple red flag to let you know there is a very tiny leak somewhere waiting to become your next big headache.
My ford is missing on #3 randomly, I run this tester a few times under a few conditions to confirm its not coolant fouling. Dark blue no matter what ya do, and thats good.
Its a limited tool designed to do a very limited test.
Perfectly explained
If u got a 25$ scan tool u can see misfire code,if clear no codes is prety sure
Every shop I've worked in for 30+ years uses this block test as the go no go test for head gaskets leaks over the gas analyzer.. This is a VERY old testing method and been around long before gas analyzers.. I use both methods and the Chemical block tester is the test that "is" the most trust the test.. Thank for a great video 👍🏻👍🏻👍🏻👍🏻
The fluid is Bromothymol blue in water; the chemical reacts to PH changes. When CO2 is 'dissolved' into the solution it forms carbonic acid, which makes the solution more acidic. This PH change causes the solution to turn from blue to green to yellow depending on how acidic the solution is.
The reason why exhaling into the tester turns it green/yellow is because humans exhale CO2.
The reason that a gas engine turns the fluid yellow, while a diesel engine turns it green is because diesel engines produce less CO2 during the combustion process.
We use this on planted tank aquariums to keep the levels of co2 at 30ppm for optimal photosynthesis and keep the fish from suffocating.
Hi mate.. How many gr of bromothymol in water? Do you know? Thanks. I want to make that solution.
Bromothymol blue
Question: Why bother with this kit at all? Can you not just measure the PH of the coolant and see if it has changed? Maybe it reacts differently to the CO2?
But there are any number of factors maybe that can alter the coolant ph, which aren't combustion gases and blown head gasket. So only combustion gas from cylinder can used.
Nice job of confirming your equipment while also demonstrating the procedure and diagnosis. Thanks!
A huge thanks to Paul Danner!! every day I learn something new from Paul, great video and editing!
I learned something every day from Paul
at first I was going to write the video off, but after you went through and confirmed you were using it correctly and then demonstrated the correct usage that was great, hats off to you, I am sure you make a fine teacher, thanks!
Thank you!
This Chemical test is a super quick go to tester in the shop....it has saved time and quickly identified faults for YEARS...it is not the only method....but it's definitely a tool to keep close!
I have never had much luck with test fluid. Since we no longer have a working exhaust analyzer I pressurize the cylinders with shop air and watch for bubbles in the cooling system. It's more work but it has never failed me yet.
how i do it too,plug out ,on tdc,valves shut,pump in the air,if good,air goes nowere,if bad,comes out of many places,exhaust,colant tank,air filter, box,or side head,gasket line,love it when you go quiet and turn the air on,same as drop down test ,then see were it goes noisy
I've never had the fluid turn exactly yellow, always light green. after tearing the engines apart always found a cracked head or blown head gasket. but you're right its scary to trust the tool when I could never get it turn yellow. I usually just fill the second chamber up cause I always suck up coolant in bottom fluid.
Nice video. Good test of the engine, and then a quality job of confirming the tool.
hey scanner Danner I love you helpful videos I'm from the Bahamas and keeps up with your videos all the time 😆
Just got this (UVIEW Combustion Leak Tester) delivered today from Amazon so was very pleased to come across this video AND the enlightening comments. Instructional videos on CZcams like this are truly timeless and relevant.
Great video! Just another great reason to keep the gas analyzer around and functional! ~Mike
exactly!
Good video. Many years ago I bought these type of testers from snap on. They were called carbon monoxide tester These wer only single chamber bottles. At first they seemed quiet reliable, unless you sucked in the coolant. Maybe without my noticing it, it was changed to carbon dioxide. It stopped changing to bright yellow, it got a little green, maybe. I bought an entire new kit, instead of just the chemical.It still didn't work. I then relied on only cylinder leakage tests. I will not put a head gasket in a car that does not need one. Keep going.,good work.
Excellent, now I can answer explain a problem on my car. I had high water usage and many leaks. Using a gas analyser multiple times never indicated a H/G problem. However one of these went green after about 3 minutes. Conclusion if the car has no running issues HC test will not work if car is missing the fluid CO2 test may not work very well.
Hey Chief, it's in the manual
"Combustion gas, when it enters the cooling system through any leak, accumulates in the air cushion above the radiator coolant level (in sealed coolant systems, this air cushion must be created by lowering the coolant level about an inch and a half). The Leak Tester analyzes this air: The blue fluid turns yellow when CO2 gas is detected in gasoline engines and green in diesel engines. The double-chamber feature of the Leak Tester assures a high level of accuracy. Conventional detection methods often give incorrect readings because alkaline particles present in the air cushion can cause false indications of a combustion leak. Alkaline particles are absorbed by the Leak Tester's first chamber, which acts as a filter, allowing only air and CO2 to reach the second, upper chamber. If the blue fluid in this upper chamber turns yellow or green, it is proof positive that there is a combustion gas (CO2) leak into the coolant."
www.uview.com/site/ywd_uview/assets/pdf/99081870_comb-leak.pdf
I tested some with my dad the other day pouring some into a cut in half water bottle, just like a tablespoon or so, then I took a straw and blew into the liquid and watched it change color pretty rapidly. There's a great difference in magnitude for the concentration of CO2 from the atmosphere, a human's exhalation, and from combustion of hydrocarbons.
The problem I found with these devices is gathering enough combustion gas in the coolant system to have a sufficient volume to test with. I'm thinking about rigging up some special no spill funnel type deal to watch air burp out the radiator or reservoir and collect into a chamber that later I draw air from into the block tester. Should be fun.
Yeah, but he discussed some issues, like the amount you lower the coolant, introduces regular air, unless done naturally over a period of running, reducing the co2 percentage of the air. then if you used a little air pocket, it would be higher concentration of co2.
Great video SD thanks for the info
The chemical used in it is called bromthymol blue. It is an acid/base indicator used commonly in chemistry. The chemical reaction is when co2 mixes with small amounts of H2O it forms carbonic acid HCO3- + H+
The carbonic acid concentration affects color.
The reaction is reversible which is why it turns back to blue based on the pH of the solution
Also paul for HC, the gas sniffers they sell at home depot measure methane which is closer to gas. I bought one from home depot and it tested negative in a brand new toyota camry.... but heres a head scratcher. In my 2014 Ford F150 it tested positive and in my neigbors F150 so im not sure if ford did some unique formulation in their antifreeze or the engines are duds... the second kinda wouldnt surprise me lol
Acidic- yellow
Neutral-green
Basic- blue
use to use Bromothymol blue to treat tropical fish back in the 70s
Thank you Mr.Paul Danner
The Lisle kit uses a vacuum hose on it instead of the hand pump and I like it. Shows clear results. Would be interesting to see you also try to ghetto test. Get your Lisle coolant filling funnel on the reservoir. Put a household CO detector in it face down. Put a grocery bag over the funnel to hold gases in and run the engine. See if the alarm goes off. I have seen it work, but not sure how sensitive it is.
I have used this chemical test before, but a different make. I red In that description that you have to blow in the tester, so the color just are beginning to change color. Because to make the tester more senstive... and then do the test😊 It worked well. Great video.
The reason you blow into it is to test the fluid for contamination. Not to "get it going" to make it more sensitive.
What I ment; if the tester is in the blue/green condition, is has a "shorter" way to yellow. And if it change back to blue, it is no co2 in the coolant.
Looks good to me . Cheers !!!
I have a chemical kit similar to what you are using and on the liquid I have states that it does have a life span regardless if you use it..that they recommend replacing it after a year or so
glad you took the time to see your mistakes
Paul 1st great vid. But may I add? If a misfire is happening some ECU,s will kill the inj. so no fuel.
2ED On a ice cold eng. a cyl. leak down test works real well (keep rad. cap off)
Joseph Tucci you would probably see the money light if so
Correct, but there is always a period on start up where the injector will fire, regardless of the misfire code. In other words, even with injector intentional shut down, it will always fire for a few seconds on initial start up
14:10 did your student actually have a blown head gasket? ◉‿◉
Really appreciate how through you are my teach
I appreciate that!
I have used the chem test for a while now and yes it isn't 100%. What i have found on gas engines is if its green its still a faulty head and/or gasket.Letting the engine heat up and build pressure while the tool is sealing the neck forces the gases through it and seems to be more reliable. Also you can reuse the fluid as long as you keep coolant out of your test tube. W/O a dout the 5 gas is the 100% way to go. Hope this helps.
great work that is common issues with avengers
Scanner Danner, great video. Very informative and we just happened to be talking about the possible ineffectiveness of bromthyml blue. Especially when the kit has been on the shelf for a while and you don't really know if its still good. Is there a gas analyzer you would recommend for less than a $1000?
I wish I did! I need one too
I think it might react better if you'd waited a while with the coolant reservoir closed (like you did with the analyzer), or even better, with the bottle already in it ( making sure it seals good of course) and then pump it.
Good tip, thanks!
I've used block test kits for years and never had an issue. The only time I've ever seen the fluid turn the yellow they show on the box is on head gaskets that are so bad that the car will blow coolant out dead cold/blow the cap out of your hand on a cold engine.
Great video
I have used an A/C "sniffer" a couple of times to condemn a head gasket failure.. after also verifying with chemical tester. Small leaks may not pickup so well though all the time.
I've also heard of false positives with this type of tester, so be careful
How the combustion leak tester work! I hope this can give some answers: Combustion gas, when it enters the cooling system through any leak, accumulates in the cushion above the radiator coolant level ( in sealed cooling system, this air cushins
Sorry! This air cushion must be creating by lowering the coolant level about inch and a half). The leak tester analyzes this air : the blue fluid turns yellow went CO2 gas is detected in gasoline engines and green in Diesel engines . The double chamber feature in the leak tester assures a high level of accuracy and this is way! Conventional detection methods excluding the gas analyzer but no everyone can have this machine in their shop... Well often give incorrect readings because of the alkaline particles present in the air cushion can course false indication of a combustion leak. alkaline particles are absorbed by the first chamber, wish acts as a filter, allowing only air and Co2 to reach the second upper chamber. If the blue fluid in the upper chamber turns yellow or green, it's proof positive that there is a combustion gas (Co2) leak into the coolant... Note: to test the Leak Tester Fluid: test the tool and fluid by exhaling into a cupped hand and sucking the exhaled air through the intake hole into the two chambers by squeezing the rubber bulb two or three times, holding the Leak Tester in vertical position. " Do Not put the rubber intake end in your mouth...
Snap on sells a portable handheld 5 gas for $2995.00 which is cheap considering what i've paid in the past. Whats nice is that it can be blue toothed to the Verus and added to your data stream or used as a stand alone. I added it to my Verus workstation when i was still wrenching full time.
Like you said in the video , gas analyzers aren't found in shops much any more which sucks cause its such a valuable diagnostic tool.
What's up brother! Long time no see. Thanks for the comment and for watching!
I thought the UView tester detects the presence of combustion gases in the coolant. I didn't know it was supposed to "measure" anything. I figured the color (green to yellow) may give you an idea as to the "amount" of combustion getting into the coolant. I take it you were focused on determining the cause of a cylinder misfire.
Hi, i have a 2008 1.8 tdci and about for month had head gasket blown and The mecanic replaced it. Two weeks ago i had a longer trio and sudenly lost power and no heat came from heater. Today i made a test with a similar tool and The first chamber turns green only if i rev The engine above 3000 rpm. The mecanic doesn t have a dynanomatric key, could be The bolts?the engine starts normally when is cold.
dear sir I have ford explorer 2010 last week I find sound under like transmission are transfer case with check engine light I find following dtc code -p0970 , p0966 ,p0962, p0765, p0760, p0755 ,p0750, p0743,
how I can fixed it what can be the problem
this car is AWD
I cant believe someone does not make an affordable hydrocarbon tester meter.....I cant seem to find one!! awesome content always love your videos!!!
if you find one, you let me know :-)
@@ScannerDanner www.aliexpress.com/item/4001211576983.html?spm=a2g0s.9042311.0.0.7f154c4dUwjGYT
This measures HC and
Freon. Both useful for automotive diagnosis
Thanks for this video. Been wanting verification of the gas measured by these tests.
Looking at your display on your four gas analyzer (I don't see where it measure oxides of nitrogen), it appears that CO2 reading is not working properly since it shows a higher CO2 reading prior to putting into the radiator overflow tank (0.58% CO2 vs. .017% CO2 when you have an HC reading of 580ppm).
If the CO2 function was working, it would have been niece to measure CO2 at the overflow tank/radiator and at the tailpipe for comparison.
Finally, and as I have been trained, one should only put the gas analyzer probe near radiator opening to avoid getting coolant into the gas analyzer and causing damage.
Thanks again.
This gas analyzer does not measure NOX. And the CO2 measurements in the decimal numbers, I wouldn't trust either. This is designed to read the higher numbers. It would be like using a voltmeter on the 100 volt scales while trying to watch a millivolt change .
As for comparing tailpipe Co2 to the overflow, it will always be significantly more at the tailpipe (around 15%)
hi, if I performed the test and there is no combustion leak, can I reuse the liquid? if yes Can it be returned in the same bottle
I have a single camber chemical tester are those any good or do the give false reading compared to a double chamber tester
Paul, if you are wondering what gas is setting it off take your tester to the weld shop of your school and shoot some shielding gas into it. If it flags you know it was from carbon dioxide. If not you know it is carbon monoxide.
to be honest I use the block tester for long time and most of the time it works, but the engine have to be in normal temperature.....
interesting video. looks like there are a lot of variables to contend with.i always used a pressure guage on the cooling system and watched for the pressure to come up quick right after starting. problem is there are many ways a head gasket or head can leak. usually a leakdown test works but sometimes ya just cant get enough pressure with a compressor to show a minor leak. you have compression pressures higher than your shop compressor but yet the combustion pressure is soooo much higher.and the leak may not even go to the cooling system.one must be vigilant oh weedhopper. discern the enemy with great care for the enemy may just lie within.
A misfire on the first couple of seconds after a cold start is becoming one of my favourite symptoms, it is more noticeable on modern engines as they usually fire-up on the first revolution of the crankshaft.
Andrew W MacFadyen, my Honda can testify to that.
'07 Dodge definitely has a blown head gasket by namesake alone.
I just bought and used one of those tools but mine is called Block Tester, it only has one fluid chamber which they say is more accurate. The instructions for mine also say to squeeze the pump for about one minute, I'm surprised yours says only 3-5 times for gas. Luckily I didn't have a bad head gasket.
The dual chamber is supposed to be more accurate. Read "Pete Sambolin" posts in this thread
Difference on actual radiator or overflow???
Does anyone have any recommendations for an affordable gas analyzer?
What about pressurized upper and lower radiator hose. I've expiereced it to be combustion pressure going into coolant jackets was my guess.
For sure that can be a symptom but you will not always have that with headgasket leaks
nice vídeo Paul
Have you ever heard of or used "the sizzle test?" I have heard of it but never seen it performed on such a minor head gasket issue. Basically you take a small sample of oil and using a strong heat source you heat it and see if it just smokes or "sizzles" indicating water or coolant.
Yes, I learned that one from a James Halderman book. He calls it the dipstick test. It is not accurate on early stages of head gasket failure. Good backyard test though.
So I did this same test. It started out Blue but then turned Green. I read on other places. Green or Yellow means a bad head gasket is that true?
Just throwing this out there without getting bashed Scanner Dan what if you use the Innova wide oxygen sensor reader will that work at all if you were to sniff the radiator.
Not sure Tommy? Thanks
wonder how long they bought the vehicle from Jimshorkey before it did that
I use aluminum foil to find oil mix in the radiator. just put a few drops of the antifreeze in the foil and heat witj a small flame. If it makes a crakeling sound it has oil in it. and I look for bubbies with engone running.
So you can re use the fluid it turns back blue sucking fresh air in ???? On the combustion test fluid bottles says don’t re use fluid. Confusion
You don't want to dump the used fluid back into the fresh container, but yes, it will turn back to blue with fresh air
That great the flowed bad
Aleskyfinis
Nice one Paul! I work in the place where we have gas analyzer for petrol engines emissions.
So 100HC (ppm) sounds high to me but is there something i need to know on warm coolant or something..?
I also have CO2 tester for petrol or diesel fired heating systems that we aftermarket install to cars to keep us and engine warm in here. So my Q is, do you have a limit how high you think it should be for only CO2 measurement?
Great video Paul again! Maybe that stuff works better when cylinder isn't' misfiring yet?
If not, i sure hope, we get some cheaper tools in future, that we can rely on..
OF course 100ppm is too high. In fact ANY HCs in the cooling system is too much. I use the 100ppm number as a 100% confirmation. I've seen gas analyzers read 60 ppm sitting on the bench.
The Co2% from the cooling system should be 0 but I do not use this gas on the analyzer because it is designed to read larger amounts.
OK Thanks!
my question is this: is it possible for there to be an HG leak that is not bad enough where it is going to leak during the compression stroke or soon after spark, but it leaks only at maximum cylinder pressure and when there is not enough uncombusted HC remaining in the cylinder that can be pushed through the HG leak to be detected by the gas analyzer such that it gives an unambiguous result? or is there always plenty of remaining uncombusted HC to detect through the HG leak when the cylinder is at maximum pressure?
I've never, not once, had a false positive or negative using the gas analyzer. If the headgasket is bad, or there is a crack in the block or head, you will see it. I can't say that I have as much confidence in the CO2 test of the block tester
I wonder if you could have a bit of "chocolate milk" looking stuff (literally just a slight bit) under the radiator cap that clears up after running the engine and never comes back? I just bought a 2013 Wrangler, and on the 3rd drive after I got it the coolant was low enough for it to "run hot" and after filling it back up it's ran better than ever (literally, it has run better than the day I bought it). I've got no signs of anything out of place, except maybe the tech that did the coolant flush not filling it up and burping it properly.
Something to definitely pay attention to. You could have a radiator transmission cooler leak that's getting into the water passages. This can end up putting coolant into your transmission and ruining it! What the transmission fluid look like? Maybe drop the pan, just to be sure, and do a fluid and filter change while you're there
can we do the same diagnóstic with the compression transducer???
Th majority of failed cylinder head gaskets don't leak a huge ammount of gas pressure from the cylinder in to the coolant side. Occasionally you get one where there is major blow out of the "fire ring" that seals the top of the cylinder and you will see definite puffs of exhaust gas from the raddiator or coolant filler cap.
The engines I work on have open deck alloy cylinder blocks with drop in wet cylinder liners, on those particular engines I see a lot of head gasket failures where oil and coolant are mixing but the fire ring seal round the tops of the pistons is still good.
I have a 2016 Malibu with the 2.0 LTG engine at the shop that's consuming coolant, put dye in the system and cant find a leak anywhere, tried the combustion leak detector didn't change, all plugs look good, engine oil isn't over full or showing traces of dye, No misfires. GM hasn't seen any reported cases on this, they are thinking a head gasket but that is just a guess. Any recommended test to do before the engine comes apart.
yes, the HC test using a gas analyzer
Very true , if no burn , the liquid test would be invalid . Agree, The liquid test is less accurate than a gas analyzer . But turning green gives good indication you are on the right track . Fluid did test right on the exhaust so guessing it is ok . Disabling spark to certain cylinders is how i get an idea which cylinders or bank the issue is on . But takes time as the fired gas has to purge out of the cooling system . I do use the liquid test , but would not say it was the best or most accurate test out there .
do you think we could make a tool an patented i know you are the master i don't have the ability to create the tink
HC test fail if ECU after misfire detection cut-off injector (some cars do this very quickly). It will be visible when water flood spark plug.
The HC test is still valid in your senario, the injector will always fire on initial start up for a few seconds and typically headgasket failures cause intermittent misfires, that are NOT severe enough to disable the fuel. If it is bad enough to create a constant misfire and injector shut-down. I promise you there will be HCs in the cooling system regardless of injector shut-down. Why? Because injectors will always fire on start up.
If it turns green that is good enough - it's a slow leak but it will probably get worse with time. Best to fix early than wait for an overheat condition.
I definitely feel better about using one of these after seeing this video - the last vid made me think it wasn't worth the money. Sure, it's not a be-all, end-all test, but at least it worked in this one. :D
Was hoping the price of those gas analyzers would come down ... but in the past 18 years I've just watched them go UP! One of those things that will never come down in price I guess. Should've grabbed one when I had the chance back then. Coulda, shoulda, woulda ... :)
me too man, but I'm not ready to rely on it like I do my gas analyzer
I don't blame you there.
Just wish the prices would come down on those things. Wishful thinking.
Would it not be possible to modify a coolant pressure tester with an adapter such that you could use your WPS and Pico to look for pressure pulses? You could sync to a spark event to figure out where the leak is.
haha, I suppose. But it would need to be pretty severe to see it (bubbles in the system) and by that point, who cares right?
I know it sounds crazy but, I'll bet you it would work and confirm with 100% certainty that you have some connection between the combustion chamber and cooling jacket.…I guessing that with this technique it might be possible to see even very small leaks. After all... ANY pulse in the cooling system that can be tied to a compression event is too much.....
Think about it...It is really very similar to attaching a “First look sensor” or WPS to the fuel pump pressure regulator in order to ID a mechanically plugged fuel injector...That procedure works pretty good.
I do not have a gas analyzer so I would have to use compression tests and leak down tests in order to ID a bad head gasket. I'm not to sure I would trust the chemical test....
Consider the case where the plugs a not accessible, confirming a bad head gasket in that situation would be difficult. Hooking up a modified pressure tester can be done in seconds.
You might even be able to eliminate pressure “noise” by disconnecting the water pump belt. Actually, now that I think about it…I wonder if you could potentially ID a sheared off water pump impeller with this
technique… Not sure..just a thought..
I am not a professional tech so, I do not have access to a known blown head gasket to test out this theory. :(
I think it would be great if you could try this out. You have the advantage to be working at a school where you can experiment a little. At the very least, it gets your guys thinking outside of the box and tinkering around with the Pico...
Paul, just an idea that may have been tried before, but what if you blocked off the upper & lower heater hoses and attached a sensitive pressure transducer to one of them and pico scoped it for pressure pulsation from the blown head gasket with the belt removed to stop the pump? Without coolant and just cranking?
To much work, too many variables brother. And a lot of water pumps are timing belt driven
I understand, thanks very much for the reply.
I have one of those UView kits and I am not impressed with it either. The only time it seems to clearly show a confirmed bad head gasket is when it's already obvious that there has been a failure. I usually have better luck filling the coolant bottle and pressurizing it on a cold engine with the spark plugs out. It usually doesn't take long for one or more cylinders to fill with water. This can be a pain in the a** on some engines. Also, most air evac coolant fill tools will lose vacuum if the headgasket is bad. This only works when everything else is sealed up 100%, not usually the case when you have a bad head gasket. I find most head gasket issue are the result of leaky coolant fittings, flanges, etc. The exhaust analyzer is a much better tool. Unfortunately, they are expensive and hard to come by at a reasonable price.
Good video l like
That free rental from autozone chemical block tester just saved me from buying a beater today.
Paul, have you ever stuck the gas analyzer in the fuel filler neck? What does it show just sniffing unburned gasoline fumes?
HC gases is what you will read. CO, CO2, NOX are all byproducts of combustion
ScannerDanner what tools would you suggest for the hydro carbon test? Any that are reasonably priced?
none, the little gas sniffers give false positives
Hi Paul, snap on make one of these kits, and i;m sure its better than that kit, i think it measure HC from Fred in UK.
I did this test from my overflow tank and also blocked off the coolant overflow tube. I would imagine that the air would be taken from the source of least resistance and since the overflow tube is fairly sizable and not restricted and right next to where the combustion tester is located, it only made sense to block it off. Not sure the guys in this video did that.
You're talking about the overflow tube of the overflow bottle? You're not wrong in wanting to block that off. It's just not necessary. If the head gasket it bad, there is enough combustion gases in that tank regardless if that tube is open to the atmosphere
Fair enough.
That kit works great if you had the engine warmed up with thermostat open
Mine turn green so did I blow it
I use the gas analyser every time . I trust it .
At around 7 minutes Paul mentioned that workshops in US " don't have 5 gas analysers anymore " . Why is that ? .. don't US workshops undertake emissions testing nowadays ?
1996 and newer car get an OBDII test only, no tailpipe tests needed.
The Hydrocarbon test is the only test I've found that actually works. I've tried all the other tests and they don't work good. Especially if you get a car that doesn't leak very bad.
I'm with you here man. I set out to disprove this fluid test at the beginning of this video and it surprised me in the end
but I think this tool will miss some early failures
@@hw5091 I’ve been a mechanic for 30 years. The best way is the hydrocarbon test.
@@1970chevelle396 sometimes you can get a low to no hc n still have some co2 going on. Generally the co2 reaches red flag levels before hc's do. Co2 is effectively hcs in the sense that it's the biggest derivative of combustion. It's just an earlier indication, if the gasses r getting into the coolant. You can be a 30yr mechanic or a person who just rented the tester from autozone- the test doesn't care about experience or feelings toward the result. A little kid who isn't color blind will get the same result.
Pressurised cooling system especially for bmw doesn't have chance this chemical test i had a bmw only overheats when u run it for long time I this chemical test never work but the problem was the head gasket
The fluid needs to be tested and the coolant level need to be correct? also if there's a dead misfire the test may be inaccurate?
Correct on testing the fluid using your breath. Correct on coolant level. It seemed to respond quicker with the system almost full. And finally, my assumption with a dead misfire, is the chemical kit may miss that, but there are variables to that too. Before a cylinder completely washes out, there would be times of "burning" in the cylinder that would produce the gases we need (CO2), so it may not miss it. Also, if you have a cylinder not firing at all from too much coolant entering it, there would be a significant amount of white smoke from the tailpipe. In other words, if the head gasket is bad enough to wash out a cylinder, you're not going to miss the symptoms.
With respect to the hydro carbon testing... Would a alcohol based coolant at high temperature cause a false reading??
I am not sure my friend. I am certainly not familiar with that type of coolant and have never had a false positive for this test (The HC test in the overflow bottle)
Nice ! Paul, if you think about it, the Co's have to be present for the chemical reaction to occur ! Vid makes me trust the kit more. The company should send you a life time supply for the free advertising! P.S If they do send me some for the suggestion ! LOL !
A very good demonstration, unless a head gasket failure is truely major it can be a difficult call to make, we need tests we can trust.
Co2 Billy, not Co
Whoops my bad ! LOL ! You picking on me because of the u - joint thing ! LOL ! Sorry ! Take Care !
yes I am....jerk. Just kidding Billy
If you search "combustible gas detector" on ebay there are some handheld units for about $120usd that I would be really keen to see someone test for this purpose. These have an LCD ppm readout. Have been thinking about getting one for some time.
to many false positives with those from what I am hearing.
The best fluid i have found is from Napa..Tthe oem brand from autozone wont change even at the tailpipe. A 5 gas is the best until a rookie sucks antifreeze into it. If the coolant has been changed the fluid test can be thrown off. if you suck antifreeze into the tester the fluid will turn a light green then turn back to blue.
do what we do with the 6 0 diesel attach a pressure gauge to the reservoir and get the motor hot boom confirmed
coolant expands when it gets hot and increases the psi automatically when the system is sealed. On a good system psi will rise in the test you described
SCANNERDANNER,
The coolant combustion tester/detector will only test the coolants fluids for a bad head gasket? The Coolant combustion tester/detector doesn't test if the water pump is work correctly or if the radiator and engine has rust and other chemicals in the coolant?
I just measures the presence of carbon dioxide. You can test the fluid by breathing into it before measuring the engine coolant gases.
Scannerdanner
1.) Whats the good and bad Percentage of carbon dioxide should be in the coolant?
2.) How do you test if the water pump is working correctly what kind of tests can I do?
3.) Do you test how must PSI pressure the water pump is pumping out?
There shouldn't be any carbon dioxide in the cooling system.
Every car is different are far as water pump testing goes and it is not always easy to tell.
Pressure is not a good test as psi will build simply by a temperature rise on a sealed system.
@@ScannerDanner thanks for the help
but what else does it detect besides exhaust gasses in the coolant?
IF there is exhaust gasses in the coolant beside it being a bad head gasket, what else can cause exhaust gasses in the coolant?
The basic-hand-tools only option if you have a 4 cylinder or other car where it's easy to get spark plugs out is demonstrated in this video: czcams.com/video/MCo0SLeMEfk/video.html
The tool is scientific and seems to work well in this case. Call me crazy but I have opened the coolant fill tank and smelling it sometimes is a dead giveaway. The HC fumes. On several makes my nose has found the problem (head gasket failure) before I even walked to the tool box. A have a big nose so that helps. lol Also tend to see black carbon floating in the tank, the dirty ring around the bath tub kind of thing. Hope all is well with you Paul. Take care
Not crazy at all brother. I do the same thing
Had a PCV valve go bad, milk in the cap and on the dipstick. Two days after changing it everything was clear.
exactly, moisture accumulating that was NOT a headgasket failure. I mentioned that because of all the naysayers who said "why didn't you just look at the oil cap?"....ignorant suggestion
sorry, that sounded like I was directing my "ignorant suggestion" to you. I was not. I was referring to other people
Hey Danner, Me again. I have a cadillac eldorado in my shop, 98 and it is running lean on bank 2, and only bank 2. The fuel trims are ~20. I've already smoke tested it, there is a small leak around the throttle body shaft seal, but very small. I've already checked all the injectors, and just incase swapped them from one side to the other to see if the lean would follow them and it did not. There are no misfires, and the o2 sensors are swinging fine. On a throttle blip test, both bank o2's go rich and back to lean like you would expect from a throttle blip. I've tested the exhaust for any leaks, incase any fresh air was tricking the o2 sensor. The only thing I can think of at this point is maybe some engine issue. You have any experience with this issue ?
Check it for an internal vacuum leak. (block off PCV and breather ports and measure vacuum on the dipstick tube. It should build pressure with the PCV system blocked off. If it goes into a vacuum, bingo, you found your issue. (BTW, this is not a common problem)
What would cause an internal vacuum leak ? (I've been googling, but all i turn up is carberated engines) I've never heard of such a thing on a fuel injected car. Sorry for the additional question, and thank you for your original reply. Some additional information, I did a compression test to make sure valves were not out of timing, and the compression test came out 220PSI across all cylinders, so that was perfect...
in the PDF you put up there... it clearly says " if the fluid turns yellow or green it is proof positive..."
The issue I had and still have is when it doesn't change
I enjoy and pick up some new knowledge and different "angles" for diagnosis when watching your videos. Thank you. I consider myself a pretty darn good diagnostic technician as well as many others do in my area. Clients, parts houses, other professionals in this industry, and even some dealer techs have the same opinion of me. I'm sure you'd concur that even the best top notch techs need assistance, and we certainly have gained from the experiences of other great techs.Thanks for the insight as far as the test fluid goes. I have never thought of what different types or brands fluid actually detect. HC's are what I've always thought the blue fluid detected. This make sense because now I realize why the fluid doesn't change when testing for HC content in some systems, but the gas analyzer does. I just thought that the fluid was old or contaminated with water, so I use it less frequently than before. On another note, you may want explain in your video to the less experienced that even though the engine oil doesn't look like chocolate milkshake, the possibility or evidence of a blown head gasket or cracked cylinder head is still there. You could explain the different areas of the head gasket that could fail. Between the cooling system and the oiling system and the cooling system and the combustion chamber will have separate identifiers. Just a suggestion. Keep up the videos. They're awesome and informative, especially for the "C" to "B" level techs that haven't been into the diagnostic game for a good length of time like you and me, and most "A" techs stand to gain.
In the video you mentioned you used to use a handheld gas analyzer. Was that as expensive as the type shown in the video? Are they available anymore? Why did you stop using it?
Of course they are still available but who wants to spend that kind of money just to ID a bad head gasket. Here in PA, every garage had one for our emission testing. But we no longer do tailpipe testing (only a few older cars and every year they grandfather in a new model year) so once the machines broke down, nobody spent the money to fix them just to handle a few model year older cars. Now, nobody has one.
Why did I stop using it? Mine broke too and it's too expensive to fix
I did a quick google search for handheld gas analyzers and I was seeing some for as low as $150-$200. That really doesn't seem like an outrageous price. But maybe these aren't suitable for automotive use? In the descriptions it states that they detect combustible gasses. Just seeing how quickly you were able to diagnose a bad head gasket using a gas analyzer, it seems like a much superior method.
i will also say if an EGR cooler is defective both tests will show a defective head gaskit
GM 3800?
i didn't mention make or model if the car is fitted with a egr cooler it will show the same result
its a fault that caught me out in the past something to pass on to your students just to watch out for it
and it is super uncommon and I have only seen it on the GM 3800 engine with the plastic intake. Can you name some engines you have personally seen this on.
it can happen to any engine with the cooler
Does anyone know how to read a 94 OBDl era car, that has an OBDll era port, that an OBDll scanner won't read?
Need a compatible scan tool. No flash code available on this in between system
Thanks for the reply.
I have this chemical tester and it has worked so far for 3 cars. 2 bad and 1 good. saved brother $1200 on a stealerships diagnosis. I had him help with cost of kit. They knew he was automotive ignorant and needed the rent paid. 😠
"Bromothymol blue (BMB) is an indicator dye that turns yellow in the presence of acid. When carbon dioxide is added to the solution, it creates carbonic acid, lowering the pH of the solution. BMB is blue when the pH is greater than 7.6, green when the pH is between 6-7.6, and yellow when the pH is less than 6." So even if it's green, you have acid in your radiator fluid, carbonic acid, which forms when carbon dioxide is bubbled through water. Diesel produces less co2 than gas engines.
For the record. It states that you should NOT use exhaust gases to test the fluid. It can contaminate the tester for future uses.
Funny because it is exhaust gases that are in the cooling system when you have a bad head gasket
If a cylinder is just not burning or firing, wouldn't you be able to tell just by an obvious miss in the engine?
Yes, you'll typically have a misfire, but not always, depending on the severity of the gasket leak. But there are many causes for a misfire that are not head gasket related. Make sense?