I'm at panic stations...

I've just replaced the timing chain, guides and tensioner on our 2007 Cooper S. I used new bolts for the crankshaft and camshaft sprockets, and got all of the parts from fcpeuro. I've got a Toledo timing lock tool set and the special crankshaft holding spanner.

The timing was quite a bit out with the old chain and tensioner:



But I corrected that before fitting the new parts:




I locked the flywheel with the pin, and the camshafts (writing facing upwards) with the tools, and didn't remove them until the job was over.

At the end I rotated the crankshaft twice by hand and was able to re-install the timing tools.

But it won't start and I've now only got about 50psi of compression on each cylinder.

I've just put the car up again and refitted the timing tools, and everything seems to be OK:







I'm at a loss as what to do next.

One other thought - with the intake off and after the timing belt was finished I soaked and scraped at the carbon buildup on the back of the valves (2 at a time, when they were closed). Maybe there's bits of carbon stopping the valves from fully seating?

 

During the compression tests, were the fuel injectors disabled and the throttle wide open?

 

No we just did a quick compression check.

I've got the intake off again now, and there's still little chunks of carbon on the valves. I've got better lighting and picks, so will chip away at scraping and dissolving it all this time.

 

Your compression may be fine, but you won't know with confidence until you do proper cylinder compression tests.

 

After a couple of days of soaking, scraping, and dissolving all of the crud in the intake and on the back of the valves the car is back on the road and zoomier than ever :-)