While performing my weekly welfare check this afternoon; tire pressure, oil level, coolant level, etc., I was slapped upside the head with the sight of THIS (below) in my expansion tank.

After the initial shock subsided, I opened the oil filler cap and peered inside. No muck visible there. I then checked the dipstick to see if the muck showed up there. I didn't see it on the dipstick, but what I did notice was the oil level wasn't registering anywhere on the indicator part of the stick. OK, down on oil level, with oil in the coolant -- not entirely surprised that I'm low on oil.

I then put the front end on stands, crawled underneath and opened the Fumoto valve to see what drained into a jar held underneath. Just oil came out, free of muck, so at this point, the oil seems to be in the coolant, not coolant in the oil.

I used the car on Tuesday, Thursday and Friday of this week, with no indication whatsoever that something was awry. The engine had all its power, the temp gauge was right where it's supposed to be... The only thing I can think of that I noticed back on Tuesday, a frigid day here in New England, was that the oil pressure indicator stayed illuminated for a couple seconds longer than usual after the engine started. Normally, it, along with all the other lights on the gauge, turns off immediately, following an engine start. This time, it just lingered a tad longer than normal. I attributed it to the cold, as it was 17°F in my garage.

So it looks like at best to worst case scenario, I have:

1) a failed (internally cracked?) Heat Exchanger/Oil Cooler, which I could easily replace myself, although the mess that inhabits my cooling system would somehow need to be cleansed/flushed out -- not sure how I'd tackle that...


2) a failed head gasket, which while I'm fairly mechanically inclined, I'm not sure I'm prepared to take that on...


3) a cracked head.

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Thoughts/advice/direction from the experts (and non-experts) would be greatly appreciated.

 

Go rent a compression and leak down tester, confirm or eliminate headgasket. Hopefully it's just the heat exchanger, very simple job. Cleaning out the cooling system might be a pain, just keep flushing the system out with water.

 

Start the car with the coolant cap off and look for any air bubbles---usually head gasket/cracked head will show air in the cooling tank (due to the compression in the cylinders). NO AIR --- likely the heat exchanger. But I would still do the leak down if your not sure.

 

Car's running strong, no malfunction lights, no perceptible drop in compression, no odd smoke from exhaust, no bubbling in coolant expansion tank when running.

Before I go out and procure a compression/leakdown tester, I'm going to try and first eliminate the oil cooler by removing it and pressure-testing it. If it fails, I've hopefully found the culprit and escaped a sizable and expensive repair. If it passes, then I need to decide whether to tackle the head gasket or other head-related failures on my own.

I assume the head gasket itself would show the point of failure if it is indeed the gasket that has failed?

I'd hate to change the gasket and button it all up only to find out that it's a crack or warp in the head.

 

did you overheat the hell out of the car? Probably not a headgasket or cracked head

 

I am going through the opposite (coolant in oil). Mine issue is likely head related at this point.

However, in the early stages, I bypassed my heat exchanger with a $1 aluminum nipple from Lowes. From my understanding of its purpose, that's not a problem as a temporary arrangement. That was likely a better test in my case. I just unhooked the two coolant hoses, hooked them together with the nipple, and threw on some temporary hose clamps. There is enough flex in the hoses to accommodate the rerouting.

With your issue, if it's the exchanger, I would imagine it would blow out oil/gunk from the front of the exchanger since it's essentially open. I wouldn't let it run and drain the crankcase doing that, but it could be a quick cheap test and you don't even have to take the exchanger off the car.

 

No, operationally, the car is normal -- coolant temp registers normal. Haven't over-heated.

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So I removed the oil cooler, and viewed the frothy milkshake consistency goop oozing from the coolant hose ports as well as from the two hoses.

After using parts cleaner to prepare the cooler for a pressure test, I was flushing out the coolant half of the unit and noticed that one side was packed in pretty hard with a much more thick (the consistency of cold peanut butter) version of the brown stuff. It didn't appear that there was much room for coolant to cycle through from the inlet to the outlet.

I dug out what I could with a bamboo skewer, then poured boiling water into the ports to help loosen up the congealed gunk. After four or five cycles of boiling water from a kettle -- I got most of what I could see -- out. I did notice some tiny chards of metal (photo #3), consistent with the metal inside of the cooler, washing out with the gunk. I have to think that the tiny orifices within the cooler are plugged up with the thicker gunk.

I pressed a rubber stopper into the inlet of the oil portion, and secured it with a C-clamp. I through-drilled another rubber stopper so I could press the nozzle end of my air hose into it, then pressed it into the outlet oil port. With about 30 psi of air pressure, and the unit submerged into a bucket of water, I noticed small bubbles coming out the coolant side of the unit. Air definitely wasn't rushing out, but it was coming out the other end, which would seem to confirm a leak. Perhaps not much of a leak is needed to create the mess I have in my coolant system now.

I've ordered a new heat exchanger. While I'm waiting, I'll do my best to evacuate the coolant system of the gunk that's inside. After installation, I'll cross my fingers and hope for the best.

 

This happened to me last year! If your expansion tank looks like that, it's the heat exchanger. It's not as hard to fix as you'd think too! Just make sure you use 8"-12" of extensions for the 4 torx bolts. They're made of trash metal that will strip if you attack it with the slightest angle. Just be careful...but Way does have some spare heat exchanger bolts on his website which saved me last time I accidentally stripped a bolt (Way you're the best)

As for the cleaning process, I removed the radiator and used a plastic fitting on the end of a hose, and ran full-pressure hose water through in every radiator hose I could find. The hardest part is getting the gunk out of the radiator, but it'll come out with enough time of washing in both directions.

If you're super meticulous, you could probably replace the water pump and radiator while you're at it. But i used the hose method for about an hour and the car never gave me problems again.

Also....

Uhhh...yeah...that's no fun.

 

That's exactly what I did. One of my 1/4" extensions has a wobble end, so that made it easy to get into those rather tight corners of the cooler.

Great advice to remove the radiator!

 

After draining the engine oil today, I was amazed as to how low the oil level had actually become. I'm guessing it was at least 2-quarts down. It's obvious (with the muck) that oil had made its way into the coolant, but I was surprised to see how little remained in the pan when I drained it...

It's amazing that it didn't overheat.

 

Took the radiator off yesterday to try and clean it. I plugged the ends, brought it inside and stood it up next to my wood stove for an hour to warm it up hoping that the heat would help to loosen up the funk within.

When I brought it back outside, I poured boiling water into the top port, where it just sat, never working through to the bottom.

Im guessing the radiator is toast. This is what concerns me; that when I button everything back up, there are other components, such as the heater core, or the new oil cooler I'll be installing, that are, or will get, just as blocked up.

I plan on several cycles of flushing the system with a water/detergent mixture once the engine is re-started. I'm hoping the pressure and heat of the system will "power through" what's left elsewhere.

At at this point, I'm contemplating changing out or scrubbing clean by hand, as many contaminated components as I can get to, i.e., hoses, coolant expansion tank, just to remove more of the gunk manually.

 

It might be worth your time to connect the top hose and see if you can get a water hose clamped to it so you can actually get some water pressure pushed through the radiator.

 

You can get a very cheap - $10 or less - Radiator Flush kit from any parts store.
It's a T-piece for one of the heater hoses; connect a garden hose & back-flush the whole system for as long as you like.

 

Yes, it looks like a milkshake. Flush that out as much as possible. You want to get that out of the system. When you are there check the triangular oil filter housing gasket to the engine and see if you have a leak, that way you can knock out another issue if it's leaking.

https://www.northamericanmotoring.co...this-part.html

11427509212

 

I took a plastic fitting for filling water balloons, screwed it onto the end of the hose, and just duct-taped the living crap out of it so it would seal onto the upper radiator opening. Ran it through the top hose for 5 minutes, then in the bottom hose for 5 minutes, then back in the top hose.

The trick is just getting a good seal, but with a little ingenuity you'll have it cleaned out fine!

 

Funny that you posted as I was flushing the radiator outside.

I picked up a brass garden hose adapter threaded into a PVC fitting that was perfect for the I.D. of the radiator hose (1-1/4"), connected it, and turned on the water. Took about 15-seconds for the water to fight it's way through, but it did.

I'm hoping that over time, the heat of the coolant will loosen what's stuck to the walls of the hose, and I presume, the interior of the engine.

 

I just read on another forum that adding a generous cup-full of Cascade dish-washing powder to the radiator will deal with the oil contamination.
Get the engine as hot as you can, add the powder & go for as long a drive as you can.
Flush well & repeat if needed.
I can't imagine there's anything in Cascade that could hurt a car engine.

 

Have you had any success getting the rest of the junk out of your engine?

Mike P

 

While it doesn't appear to be a common failure, it sure does make a mess of things. I saw this earlier when searching for things to watch out for on our then newly acquired R53.

https://www.northamericanmotoring.co...acks-this.html

 

Sorry for the long lapse, but this has been a long, messy, arduous project.



I had every intention of following this through to the end, as the forum is teaming with loads of unresolved issues, where a problem is identified, and the process of fixing it begins, then the thread just ends - with no end result. These threads do the current and future members no good, as nothing is learned. That is not going to be the case with this thread.

After I identified a failure in the oil cooler following pressure testing the unit (posts above), and while awaiting a replacement, I decided then and there to simultaneously tackle a few other projects I was going to do once spring arrived. Since the oil cooler was off the housing, and since the filter cap was also off the housing (as I drained the oil), it would be the perfect time to remove the now conveniently downsized housing and change out the housing to block gasket which had been leaking for a while. It was a bit of a project, it being my first time removing it - but once I removed the three 13mm bolts, two from the top, one from the bottom, it came out like a puzzle with some twisting and turning through the passenger side wheel well.



I then moved onto the timing cover and related components, first removing the serpentine belt, the original pre-facelift style crank pulley, idler pulley, belt tensioner, then the timing cover itself.



After cleaning the cover, I replaced the timing cover gasket, a leaky crankshaft seal, the two internal oil seals, and also replaced the centrally located M6x30 bolt (07131485184, the one with the o-ring seal in the head). I then installed a new serpentine belt, a new post-facelift style crank pulley (new old stock OEM purchased for $60), a new idler pulley, and new belt tensioner.



I learned from trying to remove the oil filter housing, that a magnetic 13mm socket would be an ideal implement to have available. I didn't have one, so removal was more of a pain than it should have been. I the picked one up, as I wasn't going to attempt re-installation without it. Once I had it, I installed the housing with new gasket in a fraction of the time that it took to remove it.

After I connected the new oil cooler to the housing, but before connecting the coolant hoses, I installed a plastic nipple between the two water hoses to bypass the cooler, as next on the list was connecting a submersible water pump (the MINI dialysis machine) in a bucket pumping fresh water (with a small amount of detergent) to a radiator hose, and circulating clean water through as much of the system that I could reach before returning, via the other radiator hose, to the bucket. I certainly did not want to plug up the new cooler with the mess in the lines, thus the bypass. The muck floated to thew top of the bucket, and only took three buckets to get the loose stuff out.



At the conclusion of the step above, I began the ritual of reassembling the car to the point of the radiator/ac condenser assembly mounted, connected and operational. I then began what would be two days of very short-lived (5-minutes long) fresh water flushes, running the car until the thermostat opened (releasing more filth from within the head)...



...then turning it off as soon as the water temp reached 204°F as not to get to boiling. I then took the lower radiator hose off, opened up the bleeder screw, then expansion tank cap, and drained the filth out before reconnecting for the next flush. With a cold engine, it ran for about 5-6 minutes before getting into the 'danger zone,' but with subsequent flushes, the engine was still warm, so I had even less time. Flush after flush, allowing about 45-min. of cooling-down time in-between, continued for a couple days/nights until the water finally came out clear, with no sign of oil.

Once I reached the clear-water point, and after the last drain, I proceeded to introduce actual coolant to the system, ran the car for about 15-minutes, then took the car on a 20-minute drive. When I returned, I waited about a half-hour for the engine to cool down, then I opened the expansion tank, expecting to see muck-free coolant, only to be shocked by a tank full of the same brown stuff!

I immediately thought that now, after all this work, I had a head gasket failure...

The next morning, I called a local, well-respected foreign car mechanic, and gave him the synopsis of what I had just gone through from start to finish. While admitting that yes, it could indeed be the head gasket, he said that while the short-lived flushes did help, what would 'really' dislodge the gunk within would be sustained driving of the car, with the heat on, coolant at a sustained 200°F +/-, and that the muck now in the expansion tank was likely to have floated to the very top of the system (the expansion tank) after the first sustained run/drive. He suggested removing the expansion tank, including the contents inside (unbolted, removed hoses, put finger in bottom nipple of tank), dumping it, cleaning it, then re-installing and filling halfway with fresh coolant, then driving again repeating the process until hopefully, all the old muck had been cycled through, floating to the expansion tank and discarded until eliminated.

Well that process (3-times) seems to have done the trick, and I'm happy to report that (knock on wood) I have clear coolant and all is well with the MINI again.



I hope this rather long outline is of help for current and future members to use as a reference in dealing with a failed oil cooler and the mess it causes.

 

That thread was the inspiration for the "MINI dialysis" setup I used. From the photos in that post it looks like the pump be used had the pressure of a fire hydrant!

I was much more conservative, using a 1/4 horsepower submersible sump pump.

 

I just want to say thanks for giving us an update and following the thread through to the end. It is this type of effort that will help others that run into similar problems. Excellent work.

 

Thanks to all who took the time to offer their thoughts, and I do hope this thread helps someone in the future.

Just snapped this pic after running the car this morning.

I never thought I'd be so happy peering into a coolant expansion tank as I was this morning...

Order is restored...

 

wow, you da man. Super impressed with your perseverance, and especially the documentation efforts!

 

^^ Amen. It's really easy to forget to document. You did a really good job cleaning that crap out too, my expansion tank never looked that good.