[Plumpcars]

Has anybody actually had a pcv valve fail in such a way as to give an intermittent air leak?

 

[kapri]

Yup, but on Pintos and small Fords so not sure how relative to your situation ? I've had pipework split due to heat and rubber contamination but difficult to find as it sort of went with the grain. Also had valves unseat from the rubber O ring in the centre or the O ring itself split while the valve looked fine.

 

[Plumpcars]

Thanks Kev. Wanted someone who had experienced it rather than a theory. The valves are the same as my application.
What I suspected was fuel boiling is now obviously not. Really feels like an intermittent air leak so will take the valve out of the equation and see what happens.

 

[langy]

Only ever seen them sieze closed Steve but i guess anything is possible, they are cheap so i used to change mine at every oil change.