Hello everyone, I’m new to the board and Mini ownership and hoping this is one of many future posts on the board.
Recently I purchased a 2008 Mini Cooper S(auto)with the N14 engine as a “mechanics special” with known engine issues. I was bored and looking for something a little more exciting to drive to and from work than my Toyota.

The car has 87k miles on it and was told by the previous owner that it was ran out of oil and the timing chain was snapped.
I’ve pulled the engine, have the short block on the stand and the head on the bench.
I only drained maybe a quart of oil out of it and have confirmed that the timing chain was snapped, along with the bolt holding the cam sprocket to the cam.
The head is not chewed up from things coming apart and no damage to pistons. I plan on disassembling the head and checking valves.

Aside from some chain rollers and pieces of chain guides in the pan the short block appears to be in really good shape. I’ve pulled the oil pump, chain(s)and splash plate and the entire rotating assembly spins very nice almost by hand.

So after that novel heres my question..... do I split the block and check main and rod bearings? Doing this means putting the $$ into bearings and bolts and most likely piston rings. I’ve never neglected a car to the point of it not having any oil in it. What happens when it gets that low??
I didn’t pay much for the car and only plan on it being my daily driver but don’t want to be upside down in it either.

Thanks in advance on any help or advise you all could maybe provide👍

John

 

I would be very suspicious of the Main bearings due to low oil and the timing chain snapping. You have it disassembled this far now. It would be a shame to not at least check the bearings and have a failure once it is put together. I assume you have some skill if you are tackling a project like this so checking bearings should be relativity easy and is low cost.

 

Thanks Minidd99.
I’ve seen King bearings and ARP main bolts/studs online. Is there a good place online for quality Mini parts at a non dealer price point?
i know the head and main bolts are one time use, what about the rod bolts?
Thanks again.

 

I would for sure replace the mains and the rod bearings...you have gone this far and if you don't, having to do it again negates any benefit of doing it in the first place.
Rings?? Is there a lip at the top of the bore? are the walls scored? If NO to both, then you can have a machine shop run a hone on all cylinder to deglaze the bores and replace the rings.

At this point...in for a penny, in for a pound...or you will likely regret the outcome...87k Miles is pretty significant for these engines.

This isn't going to be cheap and there are very few good used engines around..so you may as well do it right!!

 

Thanks 1qwkmini. You guys have confirmed what I’ve kinda wanted to do from the get go, just needed to hear it from others 😎 I paid $700 for the car and figured investing some money and not cutting corners would be the way to go. The bores have no scoring and no lip.
Any recommendations on suppliers for parts? I don’t need anything exotic as I won’t be racing it or anything crazy.

Are the rod bolts TTY?
I’m assuming if there isn’t serious damage that standard sized bearings and rings will be good. Do they even make oversized stuff if by chance I need them?

 

Go with King Bearings...they are available in all sorts of sizes from standard, 0.25 mm, 0.5mm etc
http://www.king-catalog.com/Catalog/Engine/20178487

They are available from a lot of suppliers...even Summit racing and most local machine shops can get them. Copy the main part number (rods or mains etc) and past it on the Summit site and you will see all the permutations of sizes available.

RIngs...probably stay with OEM, Mahle or Supertech....try ECS
https://www.ecstuning.com/Mini-2008-...nical/Pistons/

Have fun!!!

 

I can't help with your question on rod bolts, my aftermarket rods came with their own bolts.

As for main bearings, Bentley manual shows a chart for determining which bearings to use. They're available by different colors (referencing different sizes?), determined by coding on the block and crank. RealOEM --- https://www.realoem.com/bmw/enUS/select also shows part numbers for the different colors. For a DD, it probably won't make any difference whether or not you use this chart. I've read on forums that some guys just buy an off-the-shelf bearing kit, ignoring the factory codes, and haven't reported any problems. Maybe take a look at the procedures here --- https://www.newtis.info/tisv2/a/en/ (use the last seven characters of your VIN to ensure the correct set) and see what they recommend for replacing main bearings. Might also find out about the rod bolts here.

Have fun ---

 

Don't worry about all that color coding...it's just Mini/BMW speak for stock/0.25mm/0.5mm under/over size. Take your crank to a reputable machine shop and have they inspect the crank and see if it just needs a polish(you can then use standard size bearings) Mains and rods may both be the same or one or the other may need to be ground to the next size...0.25mm. Then you will know what size bearings to buy. If the rod bearing are really bad, you should also have them check the big end of the rods and see if the are round or oval from overheating...not sure if you have a set of micometers orwhat other equipment you have at your disposal.

Rod bolts,mains, head bolts are all torque to yield and will need replacement.

oldbrokenwind...thanks for the newtis link..I've been looking for that detailed info for a long time!!

 

Hey guys I wanted to give you a quick update and get your thoughts.
So I’m thinking I need to go out and buy a lottery ticket. I’ve dissembled the head and I’m not seeing any bent valves.
Is there any scenario that as this car was driving down the interstate that it suddenly stopped with barely any oil in it, a snapped timing chain, a snapped exhaust cam bolt with the sprocket just flying around that I wouldn’t have any bent valves?






Any good way of checking the valve guides. Both the intake and exhaust seemed to go in and out pretty smoothly.