Have a 03 R50 Cooper with a CVT that has 140,000+ miles on it. Owned it since new so I know how it was driven and it wasn't babied. I've kept it maintained and it has had it's share of repairs. The latest problem is a constant misfire in #1 cylinder. I did the usual, wires, plugs, swaped injectors, checked for vaccum leaks and nothing changed. A compression test was done and it was 90 dry and 115 wet. The car went to a shop for a cylinder leakdown test and it was, from #1 to #4 90,80,70,30 and air was heard through the oil dip stick. So I have compression problems and most likely carbon build up on the valves from burning oil. So the need for advice from those who have down a bottom end rebuild is needed. I have the ability to do this myself and have a local machine shop for the head. Can this be done with the engine in the car? It looks like eveything is accesible.

 

If you're not planning on getting the crankshaft and block checked by your machine shop, and plan on honing the cylinders yourself to set the new rings, I suppose the job is doable.

Engines that we've built/rebuilt have all been removed from the car. That way you can easily replace things like the front and rear main seals, timing cover gasket, water pump, etc.

At any rate you'll have to remove the oil pan to knock the rod/pistons out and to do that you'll need to remove the front half of the car (bumper cover, bumper support, and find some studs or another easy way to hang the one-piece module that holds the radiator/condensor.

 

Why not swap it with a motor from a low mile car with a blown cvt...
Since it sounds like you are only going to do a bare bones take it appart, and reassembly, you might come out ahead....mini engine parts are pretty $$, so a complete used low mile motor might be a better deal.

 

Thanks for the replies. After going over the cost vs. the list of other problems with the car it looks like a new car would be the smarter move. Besides the engine problem the car needs a radio amplifier, brakes on all 4, new tires, struts, rust repair and paint on hood, roof and left door. The car has been fun to drive but not sure I'll buy another Mini. Since I've owned it I've lost count on the number of windshields replaced. The CVT went bad just outside the warranty. Mini stepped up and gave me a new CVT, but it cost me $1600.00 to repair it and I know it's just a ticking time bomb. Still annoyed that the NHTSA didn't force a recall for that one. Hell they've issued recalls for less important things. An exhaust valve cracked just outside the warranty. That cost me $1200.00. Radiator fan, control arm bushings, etc. Now low compression on an engine with 140,000 miles that has been maintained. Not a vehicle with long term reliability. My wife's Mini is at 81,000. No serious failures yet and hope it stays that way. The service with Mini, when I needed them, has been better than any dealership I've ever dealt with. So I haven't given up completely on Mini. Think I'll just drive this a little while longer, visit Mini and check out some other manufacturers.