Alexander79

Hello,

I have the N62TU motor in my 2006 550i. The valve stem seals were replaced and while doing it the timing chain jumped 1 or 2 teeth on the exhaust cam. I used the timing kit to set the cams and was not able to start the car after. When I did finally get it started it sounded terrible I shut it off after a few sec. I checked the timing again and found that I had set the exhaust cams 180* off from the correct position. It broke all 16 of the cam rollers as well as the camshaft cap above cylinder #4. The cylinder head and all 16 rollers have been replaced. I'm able to rotate the motor with a ratchet and it tightens up in one spot which I'm thinking is when the cam lobes pass, I can cycle through it if I stop a second then pull again it rotates fine until that point again. I do not believe I have any bent exhaust valves on the cylinder head that was not replaced. The timing was set again with the small dots on the intake cams facing upward and the exhaust cam marks are now upward as well. I start the motor and it still sound very bad I shut it off immediately take the valve covers back off I can't see any obvious damage anywhere to cause the noise but something is definitely wrong. Do I need to do any sort of additional calibration of the eccentric shafts or anywhere in the valvetronic system to get it working or did I send this motor to hell attempting to start it up the 1st time? Should I pull off the other cylinder head to visually inspect the exhaust valves and pistons? If anyone has experienced anything like this or can offer some help please chime in.

Thanks