Background: 2010 Mini Cooper S w/ 92K, manual, new head gasket and head redone about 6 months ago.

Problem: Last week I was driving as I normally do when the overheating light came on. I pulled over as soon as I could, when I did so steam was coming out of the engine. It was steam, not smoke, and was fairly oderless. When I popped the hood, it was coming from somewhere deep in the engine, below the air intake manifold. The coolant reservoir was empty (previously fine). No leak was seen below where I had parked the car.

I came back from vacation today and needed to drive it so I topped off the coolant reservoir and made sure the oil level was fine (it was). Nothing happened, no steam no lights however when I came home the coolant reservoir was again empty. I saw evidence of a coolant leak in the engine compartment so I shot a video showing it.


I see it collecting over the transmission housing, visible in the video, and behind that area where it covers the exhaust system. I idled the car for awhile and did not see an active leak however this was after the reservoir was empty. No lights came on when I was idling.

Also, my heater is not working, I believe it happened before the first incident however I am not 100% positive.

Thoughts?

TLDR: Engine overheated w/ light coming on, oderless steam and am empty reservoir. Drove it again after filling up the reservoir and it was empty after 20 minutes. Heater doesn't work.

 

Thoughts?
Stop filling and driving as you risk serious damage until the problem is diagnosed and fixed.

 

Most likely the thermostat housing, common problem on these cars. No hot air is probably because there is air in the system. Like Minnie said, I'd stop driving it and get it fixed. Get that engine hot enough and you're looking at a new one..

 

I just did mine 4 days ago. It definitely sounds like the thermostat housing.

 

Thermostat housing leak. Part # 11537534521

DIY and parts linked below.

https://www.northamericanmotoring.co...8-no-heat.html




Thanks

 

Had the same thing happen to mine, thermostat housing.

 

Same thing happened to me when my thermostat housing failed, it runs down the back side of the transmission. What's happening is probably when the thermostat opens you start losing coolant and when it closes you don't lose coolant. Typical issue with R56 MCS's.

 

+1 for thermostat housing, thankfully it's not a really hard job or too expensive. Great time of year to lose cabin heat though, no?

 

I had very similar issue, replacing Thermostat. However the pipe under the intake manifold came loose from pump and o ring dropped out. What is best way to get that back on? I attempted to remove the intake manifold but it seems to be zipped tied in place to wires that it is impossible to remove.

 

There are a couple clips holding wiring and solenoids to the manifold, remove the intake tube from the throttle body, aside from that once the 5 nuts on the head and 1 10mm bolt underneath the manifold (near the vacuum reservoir) you are able to remove the intake manifold & throttle body as one.

You may need a new coolant pipe depending on if damage was done, I've never had to replace one, but numerous members of the forum have had to replace them.

With the right size hands you may be able to squeeze up in and complete the job without removing the intake.

A Bentley Manual is a great investment to have on hand when you're dealing with any car on your own.

 

+1 Thermostat housing. Tell tale sign is it dripping on top of the transmission. Not a bad idea to check the hoses + clamps first though.

Mini dealership wanted 800+ for the job, and it's at maximum, a $120 part. Having never played with a coolant system before, i read up on all the DIY's and went to it. A few hours and several hundreds of dollars saved later...mission accomplished.

If you go the DIY route, do yourself a favor and get the hose clamp tool instead of using channel locks. I struggled for more than a little bit to get some of the clamps off, and that was the toughest part of the entire job. Labeling which coolant line goes to which connection on the housing is a good idea too...i didn't do this, and the beers i had consumed had me a little confused when i was re-connecting everything.

 

$500+ job at the dealership that can be done for about $150 on your own. Isn't too hard. Good luck!

 

The Cable Hose Clamp tool was 2nd best tool I have ever purchased.

 

i am new to this page, but i have been lurky for quite some time. i am having loss of heat issues also, but the coolant leak is appearing near the upper left side of the motor directly under the air box from what i can tell on my 09 S. i have set up an appointment to have this checked out, but its two weeks out. would anyone have an idea on this. i am new to mini's but quite capable of DIY on motors.

thanks a

 

miniblue - On the passenger side or driver side, is the leak ? Click my link above for diagrams and how to.

Thanks

 

Ecst- driver side under the air box.

 

If its on the driver side, its the Thermostat. It leaks on the transmission and if the thermostat housing leaks down the back part, its under the manifold a bit on that long tube arm ( on the thermostat housing ) that connects to the water pipe. Click on those diagrams above.

Take out the intake , and the intake pipe going to the turbo, peak down to that thermostat housing and you should see it leaking and dripping back toward the firewall.

Thanks

 

If you are short on cash you can get a Used copy of the book on Amazon for about 90 bucks.

 

EST,
i pulled the items and checked the thermostat. there are no leaks. i am currently trying to remove the intake mainfold to see if that main pipe is leaking.

 

Dr_Romulus,
i am taking your advice and removing the Intake mainfold. i fold the 5 studs with the nuts, but i am having trouble locating the bolt you have stated. The Bentley Manual is on the way, but my car is down now. So, any help would be greatful.

 

For me that bolt was reachable through the front passenger wheel well with the inner liner out. I have found it most easy to have a swivel head and extensions. That ones a pain in the.....

 

I am having a hard time locating this bolt.

 

http://realoem.com/bmw/showparts.do?...33&hg=11&fg=40

It's item number 6 on the diagram (10mm hex bolt). I read that it may actually be easier to remove the elbow (item 5) and then take off the bolt. I can't verify that, but i can tell you it was a PITA to get that 10mm bolt off. I didn't bother putting it back on when i was done because the manifold sits solid with the 5 nuts up top. Not sure if it's going to cause issues somewhere down the road, but try getting the manifold to move even a little bit after you've got the top nuts torqued down.

 

long story short gents,
the water pump was the demon in the dark. shop covered it under warrenty. i am concerned though, it seems the water pump has been replaced once before. when they replaced it with a new one, it was leaking, so off it came and then on went an OEM model....

 

Was the second one plastic or metal ( replaced before )? Thanks and glad you got it fixed.