So I found oil in my coolant expansion tank today. Car was throwing puffs of white smoke when using engine braking (compression) and accelerating right after. Misfire code logged. Trying to think what it could be before I start panicking and thinking it's the head gasket.

- last time I was changing spark plugs (a few weeks ago) I found oil on the upper part of one of them. So I suspect the valve cover gasket leaks (on the list to change). There is oil accumulation (not active, but like, residue with dirt in it) all around the valve cover.
- just changed oil+filter+filter o-ring the other day. checked oil housing, do not see any obvious oil leaking there.
- my thermostat is most likely going (throwing a code and fan runs with the car off). actually taking apart parts to replace it right now (and the water pipe, while I'm at it). plan on replacing the intake manifold gaskets and the throttle body gasket while I'm at it.
- changed VANOS solenoid the other day.
- no obvious "mayo" on the dipstick, oil looks clean. looked inside the cylinder head (via the oil cap), don't see anything immediately obvious either.
- car has about 80K miles, never overheated, no tracking.

There are no obvious oil or coolant leaks around the engine, though (i.e. nothing drips to the floor, etc).

Can any of the above be the reason there's oil in the coolant tank, or are none of these related and I'm most likely looking at a head gasket?

Thanks!

 

Get yourself a Leak Down test done. See what the results are.

 

There's only one reason oil would be in your coolant and that's a head gasket failure and/or warped head.

 

@cooper48 I was trying to be gentle!
But 100% as soon as you said oil in your coolant, its clear... unless some one poured coolant in the oil filler, which fire that mechanic.

 

So just to update this. I've been driving my other (broken down) cars, so didn't get around to completely solving this yet, but I went to a friend's shop and he used an endoscope to go into the cylinders, the turbo, and most anywhere that oil would flow. Everything is clean as a whistle, and no oil or coolant is present anywhere it's not supposed to be. My friend's conclusion is, therefore, that the head gasket should be okay, and he didn't recommend doing a leakdown test because no oil was found in the cylinders, but that this can be attributed to valve seals. So we're going to swap those first, and then see if this helps. He thinks that he can get it done by lifting the valves and sliding the seals in, without doing as much disassembly as a head job would require. Still not a small job of course, but at least not as crazy as a head job...

 

check freeze plugs on head. there are 5 of them and 3 of them on the top of the head on my engine was rusty when i had the same problem. it's a cheap but time consuming fix if it's the problem.

 

Fascinating. Let me look at that when we’re doing the valve seals - thanks.

 

Hey, all. I'm new here but have been lurking since I bought my 2013 Cooper S back in May. I'm posting here because this thread is somewhat close to what I currently have going on, and I'm looking for some advice and insight. (note: I did post this last night in a similar thread https://www.northamericanmotoring.co...ad-gasket.html )

Bought in May '21. Roughly $13k. 86k miles or so. Check engine light was on, but they said the had done something (can't remember what) and forgot to reset it. No problems after coming off the lot.

I took it to the MINI dealer to give it a once-over. Said it was in great condition but the front passenger shock (?? I'm not really a car guy, so that might not be the correct term/part) was leaking. I took it to a mom-and-pop shop for a second opinion. They could replace that for $200 less than the dealer, so we did that. They said the car was super clean.

Later this summer, my daughter and I swapped cars while I taught her how to drive her manual Mazda 3 (three lessons, I'm kind of an awesome teacher). We swapped cars back toward the end of September or early October. I got in my car the next day and the low tire pressure light and check engine light were both on. Grrr. Driving kind of jerky.

The next day or so, I drove it to work (30 minute drive), and with about 10 minutes left, it started overheating—yellow light, then red light. No coolant smell at all. When I was able to check, the reservoir was bone dry. Got some coolant and added it. Tried scheduling with the mom-and-pop, but couldn't get in touch. Finally made an appointment back at the dealer in early November.

They said that it either needed a fuel injector replaced $1200 OR sending the cylinder head out "to get walnut blasted" (service manger's words) for $4000. Recommended doing the fuel injector and seeing what happened. Said the coolant was low but they topped it off. Oil pan and water pump had a crack, but could wait. Did new brakes.

Mid-December, I was making the same drive to work and I smelled coolant the last 10 minutes. I think I put more coolant in when I got home (I honestly can't remember—it was a busy time). A few days later, my daughter and I were coming home and got on the the freeway. Popped it into Sport mode to zoom over the the left lane. Then it started jerking big time. Got off the freeway and over to the right with my blinkers on. The Low Power Mode light came on, Check Engine light flashed a few times and went out. Started over heating (yellow then red). Pulled over to the shoulder and turned off the car. Tried restarting a few minutes later and it wouldn't. Turned over the first time, but then wouldn't turn over. After another 10 minutes or so, it did restart. I put the defrost on high and drove it to the mom-and-pop shop (Sunday afternoon) and dropped it off. 20 minute ride, and the air never heated up.

They said that they were getting misfire codes and would need to start breaking down the engine for further testing, up to 8 hours @ $1000.

Drove it home with the intention of getting back to the dealer for a second opinion. Checked the codes, and it was giving random misfires on all 4 cylinders. Stuck thermostat.

I started doing some research and decided to flush the coolant and put all new coolant in and bleed the system. Seemed to need a LOT of coolant. When I went to start the car after bleeding it, it wouldn't turn over. Looked back in the coolant reservoir and it was black (definitely had some oil in it before I drained it).

After doing some more research, I checked the oil, which looked like a chocolate milkshake. My research had me thinking head gasket (hopefully!).

Had it towed to the dealer and they found that a freeze plug broke out. Engine was full of coolant. Talked to them lat today and the said they drained the engine and put the head back on to see if it would start and it wouldn't.

Their recommendation was that it wasn't worth it to fix. That the damage could go further, to the lower part of the engine. I asked how much it would cost to put a rebuilt engine in. He said "we don't do that, but you're looking at like $9000."

Does any of this sound legit?? Does anybody have any advice?

Could the disappearing coolant from November have been a harbinger of something going on that should have been looked at more closely? Did I kill it by trying to flush the coolant?

Thanks so much!
victor