Porsche 911UK Forum

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Oil Pressure relief valves

nicklouse10

New member
Joined
19 Dec 2006
Messages
0
Hi All,

I'm trying to locate my oil pressure relief valves.

I have an 80' SC.

I've found the one in the offside rear wheel arch but are there any more and if so, where are they?

thanks

Nick


Migration info. Legacy thread was 115203
 
Nick

I have had a look in my 'Haynes' and from what I can gather the one you have found is the only one!.......Quote, "Depending upon the particular model, a pressure relief valve may be encountered in the oil tank or adjacent to the oil cooler."

Apparently on later models, 1980 through 1987, the PRV was modified and contains a longer spring, 86mm instead of 70mm, this spring needs a guide on the end opposite the piston PRV!

Hope that helps........not a lot more info in the book I'm afraid!


Migration info. Legacy thread was 115215
 
Hi Howard,

cheers for that.

I've had that one to bits and cleaned it up. It looked pretty Ok, but I still gave it the once over with some P1500 sandpaper and some polishing paste.

Unfortunately the symptoms I was trying to cure; oill cooler not getting warm even when engine temp comes up and oil pressure dropping below normal level when hot, are not cured.

any ideas?

Nick


Migration info. Legacy thread was 116564
 
Thanks Howard,

I had that one to bits and cleaned it up with some P1500 and then some compound paste.

Unfortunately this has not fixed the symptoms I was atempting to cure; lower than normal oil pressure when hot & oil cooler remains cold to the touch when engine hot.

Any ideas?

Nick


Migration info. Legacy thread was 116567
 
There has to be a thermostat involved - the oil is not sent via the cooler until a certain temperature is reached.

Its in the drivers side wheel arch.

On the 993 911 it opens at 83c/181F - which is very very hot! The 993 thermostat is in the secondary oil filter housing in the rear wheel arch.

My guess is you are worrying about something which is no problem - you would only get the radiator hot in extreme track conditions or a very hard drive in high summer temperatures.

Migration info. Legacy thread was 116584
 
Stevo, cheers for the info.

I had a chat with a mechanic friend and he’s told me the thing I stripped, cleaned and replaced was indeed the thermostatically controlled valve that lets the oil run to the oil cooler.

From what you say about the temps required to feed oil to the cooler, I needn’t worry that its staying cool.



My pal has said that there are two pressure relief valves, one on top and one beneath the engine near the bulkhead on the nearside. I’m planning on stripping these and measuring the springs to see if they are out of tolerance.



I think my oil pressure symptoms are pointing towards a sticky PRV;
I have good oil pressure at anything over 1000RPM, and the pressure climbs at just over 1 Bar per 1000RPM revs, however when the engine is hot and idling (idles a little over 900RPM) my oil light flickers on and the pressure gauge drops to 0. If you touch the throttle to bring the revs up to 1000 the light goes out immediately and the gauge shoots up to 1 bar.



I recently changed the oil and found no swarf in the old oil. My cars performance is fine and engine is not making any unusual noises. This leads me to believe that I don’t have serious oil pressure problems.



Do you think this is a fair assessment of the symptoms?

Cheers

Nick


Migration info. Legacy thread was 119071
 

New Threads

Forum statistics

Threads
124,354
Messages
1,439,451
Members
48,709
Latest member
Silage
Back
Top