Finding TDC on a 1996 Audi 2.5L TDI

Vegified TDi

Well-known member
Dec 3, 2010
Cochrane, Alberta, Canada
2006 Jetta 1997 Audi Avant Quattro 2.5L
Hello diesel enthusiasts. Can someone guide me on finding TDC on these inline 5 diesel engines please? Is the cylinder closest to the radiator #1? Or is it the cylinder closest to the firewall?

I'm supposing that I may as well pull the valve cover and check in that way...?

I have good compression on only 2 of the 5 cylinders so want to pull the head to find out what's going on. Open to ideas and direction if you have them.

Last edited:


Active member
Apr 8, 2020
03 Golf
General advice here:

Do you have a service manual for your car?

Cylinder 1 should be the cylinder closest to the front of the engine. Can you pull a glow plug and feel for air coming out or stick a rod down to locate tdc? The most accurate way is to mark the pulley when the rod is 1/4" from topping out, and mark it again when it's coming down to 1/4". Then mark the centre of those 2 marks on the pulley.
But generally the service manual should show a TDC marker, and you could pull the valve cover to see if it's tdc or 360* out.