timberwolf

Hi again all working on my 2002 a6 3.0 AVK got the red oil can and two beeps the other day so hooked up oil pressure gauge to check it out. cold at idle was 58psi at 4000 rpm it was 80 psi
once the oil temp got to around 205 it only has 11psi at idle and 45psi at 4000 rpm. I dropped pan to check screen and there was some plastic chunks and old silicone in it cleaned it all out put it back together and still have same issue. Engine sounds great no rattling or knocking. any tips on what i should look at next is there a way to bench test the oil pump? I did read something about O rings on the pick up tube getting distorted when hot can any one confirm that before i go dropping pan again.

timberwolf

while Im asking here there is a chance I might be able to pick up a wrecked 99 a6 complete car with a 2.8 in it would it be possible to just swap out the 3.0 with a 2.8

timberwolf

Today I decided to try giving heavier oil a shot which I know is only temporary fix if it worked 20w-50 and a jug of Lucius in it which did give me 22 psi at idle temp at 215 and 50 psi at 2200 rpm.

jcman

What weight oil did you use before the Lucas 20w-50?

Oil pump failures are rare on these cars and the pick up tube seal leaking is a new one to me, I had a similar problem when we had brutally cold temps several months ago and found that the oil filter was causing the pressure to collapse and it only had under 2k miles on it, I found that the anti-drain back valve was shifted on the Wix filter? Went back to a Mann filter with no problems so far.

timberwolf

I had 5w-30 with Mann filter when first started had 2200 miles on oil and filter yes it is dinno oil. I then tried new filter and 15w40 and seen some improvement so jumped to the 20w 50 and Lucas. the tube seal problem i read on here ill see if i can find it again.

timberwolf

Prospeeder
AudiWorld Senior Member
Account #: 220156

Join Date: Aug 2011
Posts: 1,842

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I have seen on 2.8, 3.0 and Im sure the 4.2 uses the same style oil pump, with metal tubes with rubber orings come from the oil pump to the block up inside the engine. I have seen where the orings get hard or distorted and cause low oil pressure warning randomly or when the engine gets hot enough. Just something to check.

https://www.audiworld.com/forums/4-2...ssure-2797670/

jcman

I've had no problems with Shell Rotella T6 5w-40 full synthetic since 08 when I bought the car, the strange thing about my oil pressure issue was that I put Pentosin Euro synthetic 5w-30 with a Wix filter last fall only to change back to a Mann filter, my car has 89k on it.

I think your on the right track with the tube seal and Prospeeder is a seasoned technician that has offered a great amount of input in the forums based on his repairs and diagnosis.

Prospeeder

I have had a few 3.0 cars with oil pressure light when hot, and it was the orings on the 2 tubes running from the pump up to the block. 4 total.