No oil pressure after oil change on 1.9 TDI AVF engine

Hello diesel mechanics,

I'm quite at a loss as to how to proceed, and maybe you have a helpful suggestion. I would really appreciate it!

I have a 2004 Audi A6 4B with a 1.9 TDI AVF engine, a six-speed manual transmission, and approximately 235,000 km (146,000 miles). It has run perfectly for the last 35,000 km (22,000 miles) since I've owned it. However, since I recently changed the oil, it's not building oil pressure. When I start it, the oil pressure warning light comes on above 2000 rpm - the red oil can symbol illuminates and it beeps. There are no error codes stored in the diagnostic memory (VCDS).

I replaced the oil pressure switch first, but there was no change.
I replaced the oil filter cartridge again - nothing changed.
The external oil pressure gauge is not registering any pressure at all!
When I crank the engine with the oil filter removed (with the ESP relay disconnected so it doesn't start), oil is pumped into the filter housing, and the oil level in the housing rises to about halfway. If I start the engine, the oil filter housing quickly overflows. A friend who is a motor repair specialist suspects an air bubble in the oil filter supply line and suggested I try this. I've already tried troubleshooting the battery twice without any success.

Okay, and now what?
The drive chain of the oil pump seems to be working fine, otherwise no oil would likely reach the filter at all. And the pump itself is likely to wear out slowly, if at all. I've noticed something like that in the past, for example, when taking sharp turns with a hot engine.

Is there another connection point for the oil pressure tester? Perhaps the inlet to the filter is indeed blocked.


Does anyone have any ideas about other things I could check?

I'm feeling the pressure of time. I'm tinkering in the garage driveway, it's getting colder and darker, and the seasonal license plates on my spare cars are about to expire soon...

Greetings, Jens.

I'd hold off on the organ experiments for now.
Does the engine still have two oil pressure switches, or just one?
hg
Herbert.

Hello,

What type of oil filter is installed?
If it's without the extension, is the oil cap still okay?

When screwing it in, it also seals the drain opening to the oil pan!

Hi,

According to the repair manual, it only has one oil pressure switch.

I have no idea whether it's the oil filter with or without an extension. There are two pictures attached. One is of my engine bay, and the other is a diagram of the oil cap and oil filter cartridge, showing that the long pin that appears in the picture below is not present on my cap, which is different from the diagram in the AKTE (stupid autocorrect!). Read the word backwards, and it... fits.

Best regards, Jens.

According to my information, the "pin" should be attached to the oil cap.

While there are models (like AMF, AXE, etc.) where it's connected to the filter, it's not connected to the AVF.

That's why the filter cartridge also includes the small O-ring, which is used to seal the front end of the shaft.

So:
This lid should normally have the part number 038115433.

Make sure to check if anything is left inside the oil filter housing.

It seems the pen must have come loose from the cap, and I unknowingly threw it away with the oil filter. This is really annoying! But it's still better than having to remove the engine to get to the oil pump...

Okay, the lid has been ordered, and I'll know more on Tuesday. I just hope the engine hasn't been damaged.

Thank you in advance, and best regards.
Jens.

Well, as soon as I installed the right parts, it started working again, just like it should!
Thank you for the expert assistance!

Best regards, Jens.

Then, but also a well-deserved for the good advice!
hg
Herbert.

...Thank you

When something like this happens, you don't always have to assume the worst; you should first look at the most obvious things .