Symptoms of a Bad PCV Valve and How to Test if It Has Failed

The signs and symptoms when a PCV valve has failed, and how to test it when if it has failed. Read here for more information. www.backyardmechanic.org/symp...
Symptoms of a Bad PCV Valve Stuck Closed
Whistling or Hissing sound
Very Dirty Engine Oil
Oil Seepage
Seals and Gaskets Fail
Symptoms of a Bad PCV Valve Stuck Open
Rough Idle
Misfire
Black Exhaust Smoke
Spark Plugs Fouling Out
Vacuum Leak

[@waltersmith3165]

I'm living most of the warning sign symptoms and couldn't figure why. Thanks!

[@MandEggsGuy]

Thank you.

[@glockmouthbullies9705]

Thx

[@neilharvey94]

It can also cause excessive oil consumption. Had it happen to a Honda Civic. Once the PCV valve was replaced oil consumption ceased.

[@PANTYEATR1]

I just hurt my high performance street engine and i think it was the PCV system that was the problem. I was using the PCV from my 5.0 liter engine on my 7.0 liter engine. I had very dirty engine oil that ended up very thin instead of sludgy. I had an oil leak from the lower intake manifold at the PCV port and possibly the rear main seal. I had a small, intermittent surge at idle. At high RPMs, it felt like misfires that wouldn't let the engine reach redline. The PCV was working as it should, but i think its flow was inadequate or too small for the bigger engine. I think it broke piston rings in 2 cylinders due to ring flutter.

[@AngelHernandez-lv7xy]

Is there any codes that would pop up when you have a bad PCV valve?

[@devan2824]

Can a bad pcv cause a misfire only when giving hard throttle? I’ve been having issues where I’m low rpm and no boost the car is fine and no engine light but if I go WOT the car starts missing and throws a code.

[@yacinebouali260]

Thanks dude, but you didn't let any gap for a question hhhh😂

[@thomaswalton9089]

I know my pcv is clogged but can this cause the car to be sluggish and feel bogged down like no power when accelerating?

[@boss_todd]

Would this give a P0456 EVAP code ? Also would it sound like you have a supercharger type whine ? That adjusts with the level of RPM ?

[@alwaysadventurous7905]

Can a bad PCV valve cause a lean condition? I’m getting a p1074 and I noticed the Pcv valve had been hanging out of the valve cover (ford things amiright lol) so I put it back in, but I’m still seeing the same code. Other than that the truck is running fine. It does seem to hesitate slightly when starting but it always starts with the first turn of the key.
I know p0174 is a lean on bank 2 error code, which is where the PCV valve is. But I haven’t found any other vacuum leaks on that side of the engine.

[@HVAC_Mechanic]

A bad PCV valve can cause a vacuum leak and a P0174 code, but many other things can also cause it. I made a video on a Ford P0174 code. Here is a link. czcams.com/video/OFMexZ2kLNc/video.html

[@iigod_liike1396]

Would it cause misfire code and cylinder suppression not all cylinder just one I change spark plug fuel injector and coils

[@daronmccartney1733]

Yes it can cause a misfire also back fires can make to much fuel dump into the cylinders as well

[@jd-nv5ew]

Would this cause the car to smoke every time you start the car when the engine is cold

[@daronmccartney1733]

Yes

[@bryant2919]

Lack of a PCV valve did not cause smog issues.

[@THEeeCOBRACOMMANDER]

Check all your hoses people! Your welcome!

[@lukehaar9380]

so my car blew whiteish blue smoke one time while giving it gas. what could it be. could it be the PVC valve

[@manicmandownup]

Yes…or coolant…or something else. Check fluid levels and check for leaks to start

[@AlexisRodriguez-it1xw]

Check spark plugs clean them or tighten them

[@daronmccartney1733]

Coolant temp sensor is going bad can cause rough idle and misfires as well will make it run lean