bugzilla

Hi folks,

Here's the current situation. Oil light on instrument cluster is ON, and Oil Pressure Gauge is at MAX (~5).

Most relevant information (maybe):
Engine has been replaced. (Long sad story.) Runs fine.
Pressure has been tested at the switch location with an independent tested.
Oil filter has been changed twice.
Oil has been changed.
Oil level is at high end of the second notch.

Other things we tried before the real pressure tester:
Pressure gauge switch was broken as it turns out, and has been replaced. Still at MAX.
Oil light is on regardless of gauge even being plugged in.
There doesn't seem to be a short anywhere.

Dash lights and instrument work has happened - I replaced the dash.

Dan Martinic

Could it be the low-oil light? That's a different sensor from the pressure

SeanR

If you have a 2 pin pressure sensor, swap the two wires and see how it performs.

bugzilla

Could do that - but the issue remains that with an external pressure sensor, they're reading a 6+, so the current sensor isn't specifically an issue (I guess). It's just what got me alerted to this pressure issue.

Also - the amateur electrician in me worries about flipping polarity and frying things. That's not gonna happen here?

bugzilla

Ah, that's an interesting point. Still worried about the high pressure situation on the other side of _whatever_it_is_ but that's an interesting point.

bugzilla

Ah. It seems that only newer 944s had that, and the light that's on is also "Oil Pressure Warning Light" (as seen here: http://www.uriarte.dk/porsche944/garage/owners83.html ).

So back to the original question then - what could raise the pressure like this? Engine sounds fine...

bugzilla

Oooooh, I found this on the intarwebz: http://944foot2thefloor.blogspot.com...-oprv-oil.html

That looks like juicy reading.

Beige944

Let me know when you get it sorted out, my car does the same thing

bugzilla

how long have you been running like this? Asking for a friend.

SeanR

You don't need to worry about that in this case. one wire is for the warning light and the other is for the gauge. When the wires are swapped you will get the gauge pegging to max with the key on, engine off. And when you start it you will have a pegged gauge and a light on.

mj951

It's common for oil pressure to read 5 bar (possibly slightly higher) after start up on a cold engine.
What's your oil pressure after it has warmed up? Should drop down to around 2+ bar at idle and normal operating temp.
What weight oil are you using?

Beige944

Been like this about a month or two. It started around the time that I changed the oil pressure sender and had the gauge cluster out, so I suspect it's an electrical issue.

bugzilla

Oh ok. Not the same thing then.

bugzilla

I drove 20 min and it stayed pegged at MAX. Using 0W-40 synthetic in there now.

Breakaway944

I think you are on the right track. OPRV controls oil pressure, so when having pressure issues it is the first thing that dhould be checked.