ehall

Just what it says. If it fails, what is the failure mode?
Thanks in advance.

Spidey944

Mine failed in the manner of, after the car was shut off, the oil pressure would bleed off after the car sat for more than a few hours. Then when restarting, the oil pressure light would stay on for 15 seconds or so before oil pressure would come back. Replaced with another 3 piece unit (used) and it never did it again.

ehall

hmm. Thanks.

KuHL 951

The OPRV can fail with high or low oil pressure. Low is more common. I had a 'failure or slow to build pressure' problem on my 86 951 with the old 3-piece style. The piston was not scored or anything. Some o-ring debris or some crud was lodged at the base of the OPRV sleeve. I pulled the OPRV, cleaned it, sprayed the sleeve area with throttle body cleaner, blew it out with compressed air and it worked like new. The first chance I got I replaced it with the 1-piece type just for good measure. That was 5 years ago and it's been fine since.

What year is your 951?

Ski

yes, for as much as it is to regulate pressure, it also serves as a check valve to prevent the drain back. If it sticks, you could blow oil out of the filter, but it also serves as a check valve to retain the oil in the pump system.

Rock

I remember Eyal951 had a problem a while back where his OPRV failed, which caused his oil pressure to skyrocket. If I recall correctly he was blowing stuff up left and right.

Rock

here is his thread for your reading pleesures

https://rennlist.com/forums/924-931-...-pressure.html

e30lolz

I just put a spare used OPRV (one piece) in a 951 and in the beginning the car was making oil pressure just fine. But after an hour of driving it would have no oil pressure at idle and then another hour after that it wouldnt get oil pressure at all on startup like it did the first time. I know this one could be bad as well but could it really work for a second then give out?? Any suggestions????