PCV Valve went bad

[JordanD]

What exactly is it, what does it do, and what causes them to go bad.

 

[MAKG]

It meters air from the intake tube to behind the throttle body, through the crankcase (well, through the valve covers, but same deal). This means you don't need a crankcase vent and you can burn whatever comes out.

They contain moving parts -- mainly a check valve -- and can wear out or get plugged. They are VERY cheap -- often around $5 -- and take a minute or two to change, so quite a lot of people change them routinely as part of a tune-up, whether they need them or not.

If the check valve sticks, it can function as an air bypass, and can make the idle difficult to control. Or it can plug, leading to pressure leaks somewhere in the crankcase (valve cover gaskets or grommets are likely).

 

[JordanD]

when it goes bad, what exactly does it cause, i generally understand it, just wanting to know so next time i don't pay 198 dollars to get it fixed.

 

[MAKG]

Just replace it with every tune up and you'll never have to worry about it again.

Quite a lot of repairs, particularly as a vehicle ages, are like that. A leaky rear main seal can be $10 in parts and $500 in labor, for instance.

Diagnosis is virtually nothing in parts, and can take a while. Some diagnoses are stumpers.

 

[JordanD]

hmmmm, that is cool, thank you so much for all your help,

 

[JordanD]

mmm another thought, are you talking about changing the hole thing, or just check valve??

 

[MAKG]

What's the difference?

That's all a PCV valve is.

Change the tubes if they are loose, hardened, or leaking.