Hello

I have a post in the B6 forum but am thinking the B5 area may be more appropriate (https://www.audiforums.com/forum/b6-...s-good-179041/).

Long story short, I had coolant in my oil along with the low oil pressure warning light. Not sure if they are related. The car has not overheated. It was assumed that it must be a head gasket which was replaced (lesson learned there as I have since learned it could be other things). The low oil pressure warning is still on so the car hasn't been driven much since the head gasket replacement. The old gasket looked good so there are doubts if that was even a contributor to the problems to begin with.

How can I test the oil pressure myself to try and determine if the pressure really is low or if this may be more of an electrical / sensor issue? I called the Audi service department and they said it would be about an hour and a half shop time to test the actual pressure. If pressure tests good, then they said it's likely an electrical issue. If the pressure tests bad (low I'm assuming), then they have to start going one step at a time with unknown costs for diagnosis and repair.

So it seems the first thing to do is test the oil pressure. GOOD = not too expensive of a fix, LOW = unknown. Can I do this myself? I have searched briefly but am not finding it yet and the Chiltons manual doesn't have anything on it.

 

I'd get an oil pressure gauge. The use of a warning light instead of one, to me, is a glaring fault on Audi's part. I'd get one and use it as both a monitor of oil health and a diagnostic tool.

Have you looked at an internally-leaking oil cooler as the source of your mixed fluids?

 

Thanks for the reply.

I haven't looked at the oil cooler yet but did see that is a common failure point. The "breather connector" (seen here https://www.mjmautohaus.com/catalog/...oducts_id=3813) and the elbow piece connected to it going into the oil cooler / filter location area had the foamy oil in them and don't believe there is actually supposed to be oil in those lines. If there's not supposed to be oil in those lines then that would seem to confirm the cooler as the problem I think.

I'm unsure where to use an oil pressure gauge. I mean, is there a specific location (hose/line) that I should be connecting a gauge to?

 

First off you need to correct the water in oil problem before you do a oil psi test!
The best way to check the oil pressure is with a gauge connected where the oil psi sender is located in the oil filter housing.
The spec is 1.3 bar (19 psi) at idle with engine at operating temperature & 3.5 to 4.5 bar (51-65 psi) at 2000 rpm.
Just remember these specs are for oil , not oil & water mixture. Resolve the oil /water mixture problem first.

 

Thanks, so the place to check the pressure is at the oil filter housing.

I'm sort of stuck on even figuring out if there is still water getting into the oil as I don't want to drive or run the car too long with the low oil pressure warning.

So far the oil looks good but its only been a few miles worth of driving since the head gasket replacement.

Some seafoam was added to the oil so there is one more thing to think about possibly effecting viscosity and possibly pressure reading?

I'm hoping to get a comfortable enough pressure reading to then drive the car 50+ miles or s, look for signs of water then put fresh oil in again with no seafoam.