Engine Won't Start After Head Gasket Replacement

[CNastyM3]

This forum and its users have helped me a lot since I've owned my 1995 M3 (about 7 months) and am hoping I can get further assistance on a pretty severe issue.

I noticed my car was running hot for a few weeks ago and had it towed to a dealership who diagnosed it as a blown head gasket. So I went the normal route buying a head gasket replacement kit and studs. When I took the valve cover off my friends and I noticed that my timing was about 45-60 degrees off. This made sense in hindsight because my car would hesitate at 4-5,000 RPM's when accelerating. So we took the cams out, the head out, etc. and had it sent away to a machine shop for resurfacing and pressure testing. While it was there I had them put in new springs and seals. Upon re-installing the cams we made sure to time them perfectly at top dead center.

So fast forward to today when I finally get done putting everything back together; it started, it ran, but it was dying so we figured there was a vaccum leak somewhere. We checked it out and could really find anything so I went to start again. I was trying to keep it from dying by giving it some gas and during one of the surges an extremely horrendous sound came from the engine. I immediately turned it off and we went to go turn the engine by hand; it wouldn't move at all. We figured it was seized somehow but were completely unsure why. So we took the valve cover back off, the cams themselves were fine, but the timing had jumped to a pretty bad spot again. We then put the valve cover back on but left the coil packs out just to see if the starter would get the engine to move, and it did.

So now I'm at the point where i can turn the engine by hand but when we do there is a clinking sound happening. Do i need to put a new tensioner in and re-do the timing? Do I need to pull the head off and check to see if a valve is bent? I'm at a complete loss as the car ran perfectly fine before the head gasket went out.

Any input at all would help a lot, thanks.

[CNastyM3]

Update: we put everything back to top dead center and found that the intake side cam was the side that skipped timing. Going to order an upper timing chain tensioner and in the meantime I'm going to take some things apart and inspect for any chips in gear teeth and things like that.

[CNastyM3]

bump

[pbonsalb]

My guess is you have not timed the vanos correctly. There is a special procedure for this and special tools required. If you know all that and are sure they are timed right, I would next suspect the cam position sensor. After that I would suspect you did not reinstall the wiring harness correctly. Make sure the TPS and IAC connectors are not swapped and that the knock sensors are not swapped and that the injector rail is connected to the update subharness not the main harness -- there is a TIS on this somewhere that shows the connections. Also check grounds including the main engine ground if you disturbed it.

[NoLastName]

You may not be getting many responses because your descriptions are a little vague. What do you mean the intake cam skipped timing? It can't really do that - the chains aren't going to skip teeth. It sounds like you did the VANOS install incorrectly. Pictures of what you're seeing with the mis-timed cams would be helpful. I hate to say this, but your description of a horrendous noise while the engine is running is not a good sign. Hopefully you used the cam block tool to hold the cams in position while setting timing, and hopefully you remembered to rotate the crank backwards a little to pull the pistons down into the bores before you bolted the head on.