where is top dead center

[pack]

is there any marks to show where TDC is and how to check timing?

[David325e]

M20? Look at the front of the crankshaft. Should be a marking on the front of it that lines up with marks on the timing cover.

[clevertd]

Boosted M30.

http://forums.bimmerforums.com/forum/showthread.php?t=1237058&highlight=m30+timing

Let me know if that doesn't explain it...

[Binjammin]

Check timing like with a timing light? You'd need a light with an inductive pickup, put it on #1 plug wire, run engine and let it flash. If you look at the timing cover a little towards the driver's side of the CPS you'll see a little raised tab. It's pretty small, if your timing cover is smegulated with years of crap you'll want to clean it. On the trigger wheel you'll see there's the toothed ring, then behind that there's a flat area. turn the crank by hand until you see the T|O mark, line that up with the tab and it's on TDC. There's no way to adjust timing like with a distributor, so really a timing light is only going to tell you is where TDC is.