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internal88, Technician
Category: Audi
Satisfied Customers: 2559
Experience:  I have been repairing Audi vehicles for over 15 years. I specialized in German diagnostic.
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I have a 2008 Audi A4 Quattro with a 2.0L L4 FSI turbo. I am

Customer Question

I have a 2008 Audi A4 Quattro with a 2.0L L4 FSI turbo. I am wondering if the crankshaft sprocket that drives the timing belt is round or elliptical? Mine is elliptical and need to know if that is by design or the sprocket is bad. Thanks.
Submitted: 6 months ago.
Category: Audi
Expert:  internal88 replied 6 months ago.

Hello, I'm Brandon.

The crankshaft sprocket is suppose to be round not elliptical. Your sprocket is bad.

Please rate me positive thank you.

Customer: replied 6 months ago.
How would it get out of round? I am aware there are elliptical and round sprockets for the TDI but have never seen it on a gas engine. Just curious.
Expert:  internal88 replied 6 months ago.

The timing chain tensioner can failed and cause damaged to the sprocket by the chain.

Customer: replied 6 months ago.
This is a timing belt engine.
Expert:  internal88 replied 6 months ago.

For the belt engine one I'm not sure how it became elliptical.

I will open up this question to other tech. Maybe they will have an answer for you.

I will opt out for now.

Customer: replied 6 months ago.
I removed the sprocket and looked at the back of it. At 90 deg and 270 deg past TDC the sprocket is machined larger than at 0 deg and 180 deg. The sprocket is elliptical appears to be correct, unless there is an updated part available.Thank you.