I have several postings with the same problem.My father-in-law replaced my head gaskets with my supervision(due to my back injury).I am a Ford master tech and my father in law has also been a tech in the air force for 20 yrs.We sent the head to get milled even though it had only .003 warpage and had it pressure tested.We used a factory head gasket and new bolts,thermostat and housing,new waterpump with new o-ring,new reservoir cap,reservoir not leaking.It also has a new radiator,cooling fans.It never smokes upon start-up,but we see coolant in the oil,and on oil cap(sweet taste,water droplets).Is it possible that I could still have a small crack in the head behind a valve seat? or am I looking at a cracked block? I have heard of cases of bad valve seats.If anyone lives near San Antonio contact me! I am in a predicament because of my back issues and cannot do any work on my car.

 

It's not super common, but check the oil cooler on the oil filter housing, we've seen a few go bad.

 

If it was the oil cooler,wouldn't there be oil in the coolant? or in the cars that you have seen them fail,have in fact failed with coolant in the oil only?

 

I... I hate to say it, but I'm here in Florida having the EXACT same problem as you, word for word. replaced head gasket, tested/resurfaced head, new valve seats, water pump, fan, head bolts, thermostat.. I'm reusing the old radiator. Had a LOT of coolant in the oil (was my reason for the work in the first place).

Now.. runs fine at speed, overheats the moment I come to a stop. I just tore into it again tonight and thought that I had found that my thermostat was in backward, but now that I look at the diagram on realOEM it turns out that it wasn't.. seems counter-intuitive to me for the spring side of the thermostat to be inside of the head at the housing and not pushing back against the flow trying to come out of it. Doesn't the coolant come OUT of the head there and then back into the top of the radiator? not the other way around...

Regardless.. I had it in there correctly (as far as the diagram shows). BUT I did find what looks like it might have been the guide for the mechanics of the thermostat, broken and stuck inside its opening. (a cylindrical pin)

I'm at my wit's end. And in Tampa, so no where near you, either.. :-/

btw.. my car's an '03, r50. (non-s, no oil cooler... as if you guys didn't already know)

oh... and.. would you believe that my father-in-law's working on this with me, too? weird.

 

Has the coolant system been purged?
If there is any air in the system it will cause overheating issue.

 

It might be worth doing a pressure leak down test on the coolant system.

There is also a sniffer of some sort that can be used to check for exhaust gases emanating from the coolant fill point.

Good luck!

Alan

 

I guess ghurm001 and I are in the same boat,along with SEVERAL others.I keep hearing that this is a unusual occurrence,but I see countless postings with the exact same thing! Really disappointed with the choice of powertrain components that mini chose,and thus disappointed in the car.I have worked on Fords for years and thought highly of german engineering until now,even if they did use american components they cannot put their german noses up and point fingers when it is ultimately their baby.It is a great car with a MAJOR weak link!

 

I, well... I hate to come in here smiling too big, but.... turns out that my issue was just as simple as the thermostat. (well, maybe the thermostat and a bad bleeding job initially when I did the head gasket)

ok. I am not a professional mechanic by any stretch of the imagination.

I distinctly remember thinking to myself as I put the new thermostat in at the time I replaced the head gasket that "this one would be better because it had three legs holding that cup that that the piston will push on." Turns out that was actually the piston for the thermostat, broken off and stuck in the opening. Apparently the reason I was losing fluid was that it was boiling off because the thermostat wouldn't open. (none in oil, no drips, sometimes overflowing the expansion tank when it overheated but then it would be real low @ the fill when I finally got around to opening it even though there was fluid in the expansion tank)

My NAPA distributor location in Tampa (their warehouse) had the thermostat in stock for $8.+ but it didn't come with the seal that realOEM.com says only comes together with it. Fortunately, the last one that I had bought separated from the seal easily because I doubt I could have pulled the original one apart without damaging it.

As far as bleeding the system goes (assuming you've drained as much of it as you plan on):

* open the two bleed screws. The one at the top of the radiator's obvious, but the other is kind of hidden down next to the bottom of the battery on my non-s. I assume it's in pretty much the same place on the s, right near the back side of the thermostat housing on the line that runs out to the heater core)

* turn key to on position, heat to on and fan to low speed (opens line through heater core)

* pour in coolant solution until air stops bubbling out of the bleed screws and it's just smooth fluid. close the screws. (I actually never did get the lower one by the battery to leak fluid like I should have, it was going in but like SUPER slow.. may have had something to do with my having used a shop vac to pull about a gallon worth of fluid out through the top of the radiator.)

* PUT THE CAP BACK ON! or it can bubble up and pour over the side when you go to start it. now start the engine and let it idle. Take the cap back off now. While it's idling the level will go down, replenish it until it won't take any more.

* put the cap back on at this point and fill the expansion tank to the max line.

* here's where I differ with the Haynes book.. they say to just let it idle to temp and then shut it down, that it would suck some of the expansion fluid in and that would be it. I actually found that when I did this I ended up with the expansion tank level going down to just above minimum but I still had air in the line when I opened it later, like it looked empty in there. So then I filled it up the rest of the way and filled the expansion tank up to half way between max and min here and drove it around the block a couple of times; low gear, high RPM.. I figured it would make more pressure in the line if the pump ran faster and push anything through that might have been a result of my vacuuming, I am not a pro. mechanic. (Have I said that?) Anyway.. I drove it around for like an hour after that last night without a problem (highway and city streets, stop lights and idling in a parking lot for a while) and left it until after work today. Expansion tank had receded to level with the top of the "min" lettering on it and the coolant level under the fill cap was down by only about an inch or so. I topped it off under the fill cap and drove it around in traffic for like an hour and a half without a problem, even had my daughter in her car seat with me. Now, 3 hours later, all the levels are perfect.

I realize that this all might not exactly apply to you if you're driving an s. Don't you guys have a pressurized expansion tank?

My suggestion to you, bmdouble, would be to at least pull out the thermostat and take a look at it. Maybe gut it and leave it wide open (put the fan on a switch if you're not sure about the sensors, maybe). at least tie a string to it and hang it in a pot of water on the stove to make sure it opens (before the water boils) and closes properly. My brother told me he just went through 3 thermostats in his 240 before he found one that worked properly. NAPA did tell me that they had the $33 version of the thermostat in stock in their Houston store at the moment so if you cant get your seal apart for their $8 version you still don't HAVE to go to the dealership to get one relatively quick without paying shipping.

Good luck to you, keep us posted on what you find. I'm off to get my headliner redone tomorrow, now that everything else is a-ok.


Sorry if this sh*t was wordy.. I drank a nice bottle of wine in celebration.

 

Congrats!!
The learning curve on the MINI is kinda steep...it is even hard for the pro's...heck the dealers have even had issues wth getting airbubbles out of the gen1 cars....on the coopers, many shops use a pressure/suction bleeding system...still a pain....things just aren't at the right height to bleed easily....
Fortunately when a shade tree guy messes up, it is just a learning experance...hopefully not too much $ was spent on random parts...but even pro's mess up..more so on mini's unless they have a decent amount of experance.
Kinda odd how complete and utter frustration turns to satisfaction!!

To the op..coolant in the oil points to a deeper issue...
goodluck.

 

got the overheating issue sorted by bleeding the heck out of it! Now I can feel the top of the radiator gets warm,and she doesn't go into high fan mode when you turn her off.But the water level keeps dropping,and opening the oil cap exposes droplets of the sweet stuff.And verified thermostat operation is correct.Thanks alot to ghurm001 for the info!I am glad you sorted your issue out.And I will have more than a bottle of wine when I sort my problem out!!!Unfortunately I will be having back surgery tomorrow and will be out of commission for a while,and will lean on my father in law to help get my car repaired.

 

I have to agree. If after having replaced the head gasket (and having the head pressure tested) you're still losing coolant into the oil pan, the only thing I can think of is that the block is cracked (or along the way somewhere you didn't torque the head down correctly).

Are you sure you followed the proper procedure for bolting down the head?

If you feel that you've pretty much done everything correctly I'd hate to say it, but... you might want to consider giving it a dose of that Bar's Leak fluid "for large cracks." It's the one with the coppery looking specs in it, NOT the one with the fibers or the pellets. It's been my experience that the ones with fibers or pellets are more likely to clog the system.

My brother and I actually used it not too long ago in a 240 that belongs to a friend of his (they drift them down around here).. you could actually SEE coolant seeping out through a crack in his block, right below the head gasket on the 3rd cylinder, exhaust side. one round of that Bar's Leak stuff and we were able to watch as the flow was cut off. Since then, the guy's put like 10k miles on it without a problem.

I always hate using that stuff though.. it just makes me feel like I'm putting a band-aid on the problem. but if your options are $10 bottle of stop leak vs. $2k+ block... I think i'd try the stop leak first.

How much coolant are you losing and over what amount of time? 1qt over a week vs. 1 qt over a 20 minute spin could indicate whether it was a leak in the block, under pressure, or a leak in a line somewhere "less important."

also.. are you COMPLETELY sure that you're not just seeing residual coolant in the oil pan? I had to change my oil 4 times before it stopped building up sludge on the bottom of the oil cap. not because it continued to leak, but because when I did the head gasket I didn't take the oil pan off and clean all up around the crank, I just cleaned as much as I could with mineral spirits (and taking the timing cover off the side of the block doesn't provide much more access). I actually had poured nearly a whole gallon of mineral spirits down into the oil pan from the head and allowed it to soak for a couple of days (in my hot-a$$ garage in FL) and it still didn't get all the gunk out. This, along with my evaporating coolant issue (due to my thermostat malfunction) caused me to think that I had royally screwed the job up or that I had a major crack in the block.. As I've already said, it just turned out to be a combination of residual coolant in the pan and on the crank, a broken thermostat and a SERIOUSLY bad job of bleeding it the first (ten thousand) time(s).

also, if you've got residual fluid in the oil it could be wreaking havoc with your paper filter.. possibly causing it to break up and restrict oil flow, and there-by reducing its ability to cool itself? perhaps complicated by your previous attempt at bleeding it?

Anyway... Hope your surgery went well!

Keep us posted!

 

I'm back! surgery went well.Layed up in bed at twilight hours because I have slept all day getting rid of my anesthetic haze.I REALLY appreciate your time replying ghurm001,and yes the head bolts were torqued down correctly.If I fill the reservoir to the max line just below the seam,at the end of the day driving it,it will be at the low part with half and inch of the shark fins exposed.Take off the oil cap and steam escapes and sweet water droplets are in the valve cover and the cap.It is possible that it could be residual,but in 20 yrs working on cars I have never seen that much residual after a successful repair.My father in law came by to see me today and told me he did some research and heard of several cases of oil cooler failures causing this same concern.Now when he first removed the head,we saw traces of chalky residue(coolant stop leak) that looked like it started at the seam where the head bolts to the block in the timing chain cavity behind the chain.Almost like it squirted behind the chain and the chain's movement trailed it up to the top of the head and pooled up around the #9 head bolt(the one closest to the passenger)which being in close proximity to the oil filter housing make me think this is feasable!at this point,I am open to any possibilities.In my experiences with cracked blocks the leaks are pretty pronounced and abrupt,that is what has me scratching my head.So I think my last plan of attack is a new oil cooler assy.

 

THE LEAK HAS BEEN FOUND!!!!!!! it is the head! removed the valve cover while the car was still warm,looked behind the timing chain on the head and saw water dripping from a hairline crack on the face of the head behind the timing chain area.This is how I was getting water in the oil and no oil in the coolant.I hope this helps others with similar concerns of no white smoke,no misfire,just the case of disappearing coolant and milky oil.