Background story..... we special ordered this Mini Cooper S at the end of 2007. We tend to keep cars for a prolonged period of time so we loaded it with options. It was over $35,000 plus tax and license. It is one of four cars we have and my wife's primary car. It currently has 35,505 miles on it. She tends to put under 5,000 miles on it a year. It is garage kept and all maintenance is up to date. I change the oil once a year using Mobil One 0w-40. The recalls have all been addressed. Over the last eight years the car has had zero issues.... until now.

Last Friday my wife when out to the garage and the Mini wouldn't start. The engine would spin, but would start. I suspected the HPFP as it was the original one. I had the Mini towed to the local dealership and told them my what I suspected. Yesterday I got a call from the service writer. Two cylinders had no compression and the other two were low. Leak down was 80 per cent. She asked if it had been overheated... it hadn't. She wanted permission to remove the head and see what the problem was. She suspected a top end rebuild for $5,000.

I had the car towed to an independent mechanic I have used before and trust. All they work on is Minis; http://motoringmagic.com/ They did a compression check while I watched and came up with 30, 40, 50, & 130 PSI. They removed the valve cover and the chain and tensioner looked good. He suspects the head gasket may be the issue but isn't sure until he looks further. On Thursday they'll tear it down and see where we're at.

We have a deposit down at two dealerships to order the new BMW M2. It will take the place of the Mini. I hate spending money on repairs, but I would have felt worst selling the car to an unsuspecting buyer and having it blow up on them. Oh well. All part of life and cars.

Stand by for more......

 

Interested to hear what they find out. Sorry to hear about your misfortune.

 

Closure.... The engine had a major carbon build up and frozen rings. I have changed the oil every 5,000 miles since new. $2800 and it is good to go for another 35,000 miles... or until I sell it this year.

 

Since the N14 engine was introduced, all the forum following I've done points to carbon buildup as being one of the shortcomings of that particular machine. There is a lot of advice given about ways to de-carbon that puppy. Some suggest 'Sea Foam' and others walnut shell blasting. Oil changing doesn't fall into the overall scenario of the buildup problem. If you've gotten that kind of mileage with no other problems then doing what you can to mitigate any further build up should give you many more relatively trouble free miles.

 

I think there are three other contributing factors. First, it is an automatic and shifts too early allowing it to run at too low of RPMs. Second, my wife drives it too easy. And lastly my wife drive very short trips in the car not allowing the oil to come to proper operating temperature. Those three plus the poor engine design that allows this to occur. But... I am guessing here as I am not a mechanic.

 

Pretty much everything you just said.

These cars need to have the oil changed at 3-5k miles and need to be driven HARD from time to time to blow out the carbon.

 

Commonly referred to as an 'Italian Tune Up'. Take it out on a back road and blow the cobs out of it once in a while.

 

I'm glad to hear that it is fixed.

 

I've read plenty of stories of these motors having carbon buildup on the intake ports, but this is the first I've read of one having buildup on the rings. Even to the point of having frozen rings and bad compression numbers? That's impressive for bad reasons.

Glad it's fixed though. Did the mechanic say what he did to free up the rings? I've used Marvel Mystery Oil to free up stuck rings on plenty of older engines, but I'm not sure if that would be appropriate here or not.

 

" Closure.... The engine had a major carbon build up and frozen rings. "


Wow never heard it being that bad.

 

I think the OP is right, it's just harder to do with an automatic (driving it hard) even in Shift/Tiptronic mode.

 

I went by the shop when the engine was apart and before the repairs were completed. The top of the piston heads looked like they had a heavy coat of soot on them and the rings were frozen to the pistons. They did not have any spring to them.

Part of the repair was to replace all four rings.

 

That's a pretty intense build up. Did you take any pictures of it by chance?

 

No. As usual, in hindsight I should have.

 

The carbon and blow-by deposits (from burning oil) form in the ring grooves, I came across a product the removes these carbon deposits and performed a compression test before and after at 55,000 miles. In one cylinder I gained 15 psi just running a can of BG EPR (scheduled oil change) which was designed for DI engines, it evened out the compression readings across all cylinders. You'll never be witness to blacker oil in your lifetime!

I strongly recommend it!

 

BG offers several products aimed at cleaning up after messy deposits and such.
https://www.bgprod.com/

 

Nice looking mini, glad it's back together. What type fuel do you use? Is Calf. fuel mix different than other states?