I could use a little help. My 07 R56 Cooper S has developed a significant oil leak. My alternator went out and while I have my car apart I need to figure out where the heck this is leaking. It looks like there is a leak in my coolant system too. After getting this apart it's super wet all around the serpentine belt and the alternator was really covered w/ oil. Here are a few pics. I have heard of the timing chain tension screw potentially causing a leak. Are there any other common causes? What's the best way to pinpoint the source, there is just oil everywhere. I was thinking of cleaning a bunch of oil off and putting it back to together enough so it will run and cranking it up and try to pinpoint it then. Any thoughts would be greatly appreciated.

Looking down through the top of engine. A/C compressor is covered in oil too. Alternator was just above the A/C compressor before pulling it out.



Looking through passenger wheel well at serpentine belt pulleys.


Alternator covered w/ oil.

 

If that's all oil, you either have a major leak, or it has been leaking for a while. When was the last time you added oil to the engine? Are you low on oil? If so, by how much?

If you are not loosing too much oil (above usual), then it's coolant.
In that case, it's curtains for your water pump. For an '07 car, you are likely north of 60K miles and over-due for a water pump leak. Replace it ASAP before it completely lets go and you run the risk of overheating the engine.

Pic #2 suggests ample oil seepage from the valve cover. If nothing else, you should plan on getting the gasket replaced (easy 1 beer job) soon.

HTH,
a

 

It's been leaking for a few months. It would leave a few drops where ever I parked it. I didn't realize how much it was until I starting pulling out the alternator. I would need to put about 1/2-1 quart or so per month. I was also looking around the timing chain tensioner for the oil, but not really seeing anything. From what I can tell it looks like the oil might be coming from around where the timing chain is. Could the crankshaft seal be failing? I did pull the valve cover tonight and it doesn't seem to be coming from there. It's just really tough to tell. I think I need to get the alternator back in and crank it up and inspect it closely.

I also saw some antifreeze upon closer inspection. I was trying to look around the water pump to see if the coolant is from there, but I'm not really sure at this point.

 

How many miles on the car?
I will assume you drive less than 1K miles/month, so 0.5-1 quarts gone is excessive.

I know access is tight, but try to at least clean the top of the engine around the valve cover (brake cleaner + paper towels work great), to eliminate the possibility of massive valve cover leak. It's relatively easy and inexpensive step.

When I took my engine out the other week (long story, pic below), what looked like a minor valve cover seepage had produced solid coating of oil on the entire pulley- and back sides of the engine.

If it's not the valve cover and not the chain tensioner (re-torque it!!), then we are down to the crankshaft seal. I haven't heard of it failing often, but the good news is that it's inexpensive and I believe you can get to it by removing the passenger-side fender liner.

If the front of the engine is oily as well, suspect the oil turbo cooling line leak. They all go around 50-60K miles.

I would plan on replacing the accessory/serpentine belt as well, as all that oil has shortened its lifespan.

On the pulley side of the engine, that's the only logical place from which it could originate.
Again, how many miles on the car ?

a

 

It would almost have to be coming from the valve cover. The timing chain tensioner is on the back of the engine on the passenger side.

 

I've got ~76k miles on it. It's probably more like 0.5 qt. I ran my fingers all along the timing chain tensioner and just don't see any oil residue. I will re-torque it. I wish it was the valve cover, but at this point I don't think it is. I hope it isn't the crankshaft seal. I will clean it up really well and get my alternator back in and swap out the water pump and get it running again and inspect it closely while the car is ripped apart. BTW, is it safe to run it w/ the intercooler hose disconnected? Not drive it but crank it up and look for the leaks. Will also take your advice on the belt. Thanks for all help.

 

Yeah, I don't think it's the tesioner...If it were the valve cover, I would think I would see a trail of oil somewhere around it, but don't. Where is the oil pump...could that be a possibility?

 

I would not do that - you will be bypassing turbo compression of the air intake, as well as MAF air measurement = basically, letting in unmeasured atmospheric air into the engine. At best, you will run super-rich.

Try to re-plumb the air intake pipeline before test firing.

a

 

At idle the turbo isn't providing any compressed air. I can't imagine it would run well since you're not metering air properly. You might get a CEL. I'd try hooking up the intake tubing the best you can.

I kind of forgot about your question earlier. If it is the front crank seal I don't think you have to disturb the timing chain to replace it.

 

I haven't had to deal with oil pumps on a MINI, but usually they sit in/near the oil pan. If you trust the following picture, that is also the case in an N14 engine - pump is at the bottom, driven by an auxiliary chain off the crankshaft.

http://pictures.topspeed.com/IMG/cro...-28_600x0w.jpg

However, the parts diagram below suggests that the oil pump has its own cover. In which case, it could leak:
http://www.realoem.com/bmw/showparts...28&hg=11&fg=30

I will take a closer look at the spare engine sitting in the garage later today to confirm if that is an external cover that could leak.

a

 

Thanks for the diagrams it helps.

 

You're engine puking oil out somewhere, probably shorted out your alternator. Do not drive it period!

 

[QUOTE=gatorbait01;3928103]
Sorry it took me a while to get to it, but below are the out of the car pics of the pulley-side of a used N14 engine.

As you can see, there are no external oil pump covers.
The only obvious places for the oil to seep out, top-to-bottom, would be:
- valve cover gasket (they all do it to some extend!)
- cylinder head gasket
- draft shaft seal
- chain tensioner (many do it if the tensioner was under-torqued)
- cylinder bottom gasket
- oil pan gasket

However, oil leaks are rarely obvious. It may leak in one place, then gravity and air-flow travel around multiple parts of the engine to drip elsewhere.

The only way to tell for sure it to clean the visible paths of the oil leak, watch them re-emerge, then trace to the source.

Hope this helps,
a

 

[QUOTE=afadeev;3929788]
Afadeev,

I figured it out! It's leaking at the "Chain Guide Bearing Bolt". The bolt was finger loose. Would there be any adverse affects of this being loose? How about the torque specs for this, does anyone know? After replacing my alternator and H20 pump I learned quite a bit so far about my mini. Found a sheared bolt in on my motor mount. Looks like someone who owned it before me sheared it off and decided to just leave it. Can't believe Mini wanted $120 for this piece. Also, if my harmonic balancer was exposed to oil and the gasket is a bit swollen, should I replace this? Mini wanted $400 for this piece which seems absurd. Thanks for your help.

 

It looks like at some point in time it was also leaking out of the valve cover also, see how the oil flows down from the valve cover? Now you have oil leaking at your chain guide bolt.

Great catch btw!

 

Saw your post looks similar to a problem I had on my car
https://www.northamericanmotoring.co...-oil-leak.html