Let me start by saying I've known my water pump was going out based on the sound it made in the morning. I thought it could have been the wheel so I replaced it and the tensioner but the noise was still there. Only for a few seconds in the morning during warm up. I ordered a replacement pump but haven't had a chance to do the labor yet.

This morning I was running my boy to school when I heard a small clunk like noise (kinda like a pebble bouncing in the wheel well) and about a 1/4 mile later the engine started to sputter and the 'low power' mode engaged. I managed to turn around and limp it home to get my R53 and finish dropping him off. When I returned I got out the scanner and it shows Cylinder 1 misfire. I removed the coil and plug and cannot see anything weird about either (all were replaced about 20k miles ago). I put them back in and cleared the code. Restarted the MINI and the code came back almost immediately and the sputter is still there.

My question is this... On the N18 engine is there ANY possibility that if the water pump failed or came apart it would damage cylinder 1? I'm not familiar with the internal layout of the N18 since I haven't had one apart (yet).

Any help is appreciated!

 

The water pump is external to the engine and if it fails, the failure will be local.

do a compression check and also check for a stuck fuel injector.

 

On the N18 are you able to swap the coils like you can on the N14? If so, try swapping them around and see if the misfire follows the coil, might be time for new coil packs and plugs, and would most likely be your easiest option to check.