Oil Leak: A4 B5 2.5 TDI (1998) - Fix It!

Hello.

My A4 2.5 TDI, manufactured in 1998, constantly has an oil leak that I can't seem to fix.

The following items have been replaced so far:
-Oil-sealing poetry
-VDD
-ZKD
- Simmering seal, front of crankshaft.
- Oil separator (now a cyclone oil separator is installed).

Furthermore, I added some Wynns Oil Stop Leak, but it didn't improve the situation.
Could it be due to the current oil being used: Mobil 1 0W40?


Best regards,
Michi.

Just measure the crankcase pressure.

Hello,

How can I measure it?

best regards
Michi.

Manometer with appropriate measuring range or water column. Connect to the oil dipstick.

Where can I get a pressure gauge like that?
Sure, here's the translation:

"A link would be great."

best regards
Michi.

"I have no idea, I just grabbed a natural gas data logger (up to 100 mBar) – I happened to have a few of those lying around... But they cost between 1000 and 2000 euros each, so it's not really interesting."

Measurement device for owners of V6 engines with low pressure: You take a transparent tube and hang it in a U-shape, so that the U is, for example, 3 meters high. Then fill it halfway, i.e., 1.5 meters, with water. This results in a measurement range of approximately 0.15 bar.

Use a permanent marker to draw a line at the minimum level. Leave one end of the hose open, and attach the other end to the opening of the dipstick.
Now, the crankcase pressure pushes the water column in the U-tube downwards on one side and upwards on the other. Each 10 cm from the reference line corresponds to 0.010 bar, which is equal to 10 mbar.

I don't know the exact target range by heart, but it was posted somewhere in the forum before. If the water is splashing onto the garage ceiling, you can stop the measurement even without taking any measurements.

Best regards, Rainer.

@Rainer: Don't you think that a water column of 1.5 meters would measure a higher pressure than an oil column of approximately 70 cm?
This means that, in the event of a problem, the oil would be pushed out of the dipstick tube before the maximum selected measurement range of 1.5 meters water level is reached.

The pressure should be a maximum of 5 mbar, which is equivalent to 50 mm water gauge. There is no oil anywhere, as the measuring tube does not extend below the oil level.