Oil Pressure always high

[martin.vesty]

I think this is my last call for support for now - Apologies for the recent flurry of topics. I guess always the case for owners of a Marque not owned before.

I've searched and found a few articles regarding OP senders but can't see the same topic. I also don't have a variable resistance potentiometer to run the test as in Clark's. Hence asking the wise souls on here.

My oil pressure is zero when the key is in the on position (before starting engine). I mention this as Clark's refers to OPS being past its best if the oil pressure immediately goes to 5 with key in On position.
Once started and from then onward when the engine is fully up to temp the the pressure seems to be static at about 4.5.

When I did an oil change and general service a month ago I removed the sender, checked the face was clean, checked the terminals and made sure the connections were good when I refitted it.

Same outcome with the pressure.

Anyone had the same? Suggestions?

I was assuming I should fit a sender but I guess that means dropping the oil again so I'm in no hurry to do that this side of winter.

 

[scam75]

Hi Martin

First off, you can change the oil pressure sender without dropping the oil. You'll get a little bit of spillage but not much if you have the new sender ready to screw in. It is awkward to tighten and a cut down (24mm I think) open ended spanner is the ideal tool. Small hands also help! You can get a decent new sender for about £30/£40.

First thing I would be doing is getting a proper oil pressure gauge on it so you can see the actual oil pressure, then work back from there. Sender, dash gauge, wiring.

4.5 bar is wrong for a warm engine (assuming this is engine idling you are talking about). A fresh engine will be 3 to 3.5 bar at hot idle. A worn but serviceable engine between 2 and 3 bar. IIRC Porsche states that 1 bar is good enough at idle to keep things lubricated.

A faulty oil pressure relief valve (OPRV) could cause your issue assuming you are seeing a correct reading. OPRV's are eye wateringly expensive new but sometimes it is just the o-rings that need replacing and these are pennies. I'm going to guess however that your sender or wiring is suspect. Get a local garage to either check your pressure with a proper gauge or ask to borrow one and do it yourself and report back.

Stuart

 

[scam75]

Also if the 2 terminals on the sender are back to front, you'll see 5 bar on ignition and with the engine on. Does your gauge move at all or is it painted on stuck at 4.5 bar?

 

[martin.vesty]

Thanks Stuart for that very helpful advice.
I’m pretty sure the terminals are correct as one is a spade and one a ring. It’s never been touched in the cars life.
I’ll get a new sensor and swap it out then take it from there if the reading is still constant. I’ve a specialist garage close by that I can ask to check the pressure.