VCDS: Diagnose crankshaft bolt loosening symptoms.

I have an AFN engine in my Volkswagen Golf 3 (252,000 km).

Given that the issue of the gradually loosening crankshaft bolt is also known in AFN engines, I'm wondering if there are any symptoms that could be detected based on the injection timing rate (using parameter MWB 4) or in the TDI timing graph.

Thank you for the responses.

Best regards, Klaus.

I think that if it becomes visible, you can also see it by observing a wobbling pulley/vibration damper.

Hello,

Yes, you can see that by looking at the fluctuating values in the TDI timing checker. However, as mentioned before, it would be easier to check the vibration damper/pulley, as you need to have a comparison to "before" via diagnostics, or you could check it every day.

Best regards, Rainer.

Hi there.
The emphasis is on "fluctuating" or "varying". Fluctuations of, for example, 50 +/- 2 for the value 2 in MWB 0 are normal.
If you suspect a problem, confidently grip the central screw with the wrench and turn it counterclockwise. Either it will loosen, or it won't.
hg
Herbert.

Quote:

If you suspect a problem, confidently grip the central screw with the wrench and turn it counterclockwise.

Either it will loosen, or it won't.



If it's properly secured, it shouldn't open with a key or a 1/2" T-piece.