Oil Pressure Relief Valve
12-11-2007, 02:35 AM
#1
Drifting
Thread Starter
Oil Pressure Relief Valve
Few questions on the OPRV. The FSM's say to replace the o-rings. Anyone know where to find these little buggers?
Also, any tips on how to check to make sure the OPRV works/ clean it? I remember someone having rigged their air compressor up somehow.
Thanks!
Also, any tips on how to check to make sure the OPRV works/ clean it? I remember someone having rigged their air compressor up somehow.
Thanks!
12-11-2007, 03:00 AM
#2
Rennlist Member
Here's an old post from the E-Mail lists that may be of help. Keep in mind that there was more than one version of the OPRV, so you need to check that first before sourcing the O-rings. HTH.
Hi all,
a long story comes to an end. I fixed it. I want to
summarize the issue for all who are facing the same
problem and for rennlist records.
For all who are not in touch with it. I had a 'moaning'
noise front right in my 1991 944S2. It was rpm independent
and happened on a hot engine only. After a lot of testing
and searching it appears to be the oil relieve valve.
Diagnose:
- warmed up engine to normal temperature
- engine running at idle speed
- turn on front lights to (min.) low beam
- touch oil lines from engine to
oil cooler at the engine side.
( put your left arm very carefully
into space between passengers side
headlight and windshield washer
reservoirs. Do not touch power
steering trombone cooler lines.
Oil cooler lines ar the big
rubber one's underneath. Be careful
not to smash your fingers into
power steering pump belt!!!)
- slowly raise engine speed by opening
throttle (with your right arm) until
moaning noise becomes audible
- oil lines are now pumping and vibrating
Fixing:
- buy two rubber rings, part# 999-707-145-40 and 999-707-144-40
(one is a green one, other a black one, about $1-2!)
- remove plastic air deflector pan mounted under engine
- locate 24mm 6-edge-screw near exaust, mounted into engine
housing below oil-to-water-cooler-oil-filter-unit, right side.
- remove 24mm 6-edge-screw
- a metal pipe thing comes out
- at front end you will see first old rubber ring
- 6-edge-screw and metal pipe are not fixed together,
both things are weakly fixed by the second rubber ring
which is not visible
- pull heavily 6-edge-screw and metal pipe in two directions
to come apart into two pieces.
- NOTE: A spring and a bolt comes out of it. Do not lose
it! Remember, which one is assembled first, second etc.
(Spring, bold, oil piston)
- now you see the second old rubber ring, it will be demolished.
- replace this second old rubber ring by the new -BLACK- one.
- assemble Bold and Spring in right direction.
- push 6-edge-screw and metal pipe carefully together to be
one piece again, weakly fixed by new -BLACK- rubber ring.
- replace first old rubber ring by new -green- one on top of tube.
- clean the whole thing carefully
- replace old aluminum seal by a new one
- assemble 24mm 6-edge-screw (seal+pipe-screw unit)
- mount plastic air deflector pan
- check oil level
- run engine and check for leaks
- oil pressure between 5 (cold) and 2.5 (hot)
- fixed.
Thanks to all who responded to me.
Best regards
Juergen
a long story comes to an end. I fixed it. I want to
summarize the issue for all who are facing the same
problem and for rennlist records.
For all who are not in touch with it. I had a 'moaning'
noise front right in my 1991 944S2. It was rpm independent
and happened on a hot engine only. After a lot of testing
and searching it appears to be the oil relieve valve.
Diagnose:
- warmed up engine to normal temperature
- engine running at idle speed
- turn on front lights to (min.) low beam
- touch oil lines from engine to
oil cooler at the engine side.
( put your left arm very carefully
into space between passengers side
headlight and windshield washer
reservoirs. Do not touch power
steering trombone cooler lines.
Oil cooler lines ar the big
rubber one's underneath. Be careful
not to smash your fingers into
power steering pump belt!!!)
- slowly raise engine speed by opening
throttle (with your right arm) until
moaning noise becomes audible
- oil lines are now pumping and vibrating
Fixing:
- buy two rubber rings, part# 999-707-145-40 and 999-707-144-40
(one is a green one, other a black one, about $1-2!)
- remove plastic air deflector pan mounted under engine
- locate 24mm 6-edge-screw near exaust, mounted into engine
housing below oil-to-water-cooler-oil-filter-unit, right side.
- remove 24mm 6-edge-screw
- a metal pipe thing comes out
- at front end you will see first old rubber ring
- 6-edge-screw and metal pipe are not fixed together,
both things are weakly fixed by the second rubber ring
which is not visible
- pull heavily 6-edge-screw and metal pipe in two directions
to come apart into two pieces.
- NOTE: A spring and a bolt comes out of it. Do not lose
it! Remember, which one is assembled first, second etc.
(Spring, bold, oil piston)
- now you see the second old rubber ring, it will be demolished.
- replace this second old rubber ring by the new -BLACK- one.
- assemble Bold and Spring in right direction.
- push 6-edge-screw and metal pipe carefully together to be
one piece again, weakly fixed by new -BLACK- rubber ring.
- replace first old rubber ring by new -green- one on top of tube.
- clean the whole thing carefully
- replace old aluminum seal by a new one
- assemble 24mm 6-edge-screw (seal+pipe-screw unit)
- mount plastic air deflector pan
- check oil level
- run engine and check for leaks
- oil pressure between 5 (cold) and 2.5 (hot)
- fixed.
Thanks to all who responded to me.
Best regards
Juergen
