About two weeks ago I sent my 2006 mini cooper s (46,000 miles) to the dealer for some AC work. After inspection the mechanic recommended replacing the engine mount on the car in addition to the AC compressor that had locked up. Got the car back and started noticing a loud clunk when shifting coming from the engine bay. Opening the hood yesterday I immediately noticed that the engine mount nut was missing so the engine was basically bouncing around on the mount for two weeks. I replaced the nut today and the noise had gone away but I was wondering if running the engine unsecured like this could break anything else? Thoughts?

Missing engine mount nut

 

I suspect you'll be ok, but I'm sure it didn't do your exhaust manifold any favors, and it probably put some extra stress on the other motor mounts. If you're not having any problems right now, I doubt you'll be able to get the dealership to take responsibility for it, but you should try and get it documented so that if something pops up down the line, you have a chance of making your case with them.

 

+1 on getting the Dealership to take ownership for failing to finish the job. Agreed didn't do your exhaust manifold much good, but for the most part the short duration may not have caused lasting damage or long term problems.

Best advice is just keep it under observation and keep up on maintenance.

Best of Luck.

Motor On!

 

Yikes. I’ve seen some poor workmanship but that one....

 

Somewhere else. Check around with other MINI folk in your area for a solid independent shop who values return customers..

 

I would not be surprised, if the exhaust header will not break soon from now!
The mechanic was surely not the best, which is what you paid for! You need to see the dealer on this. If they do not address it, you need to put in a consumer complaint.