my 2005 S model had warped head replaced about 2-3 years ago. Later replaced the power steering pump and fan. I seem to recall pulling apart front end to access rad, as we wrongly thought the fan always running was rad fan, and later discovered it was the power steering pump and fan causing it to kill battery. Point is, I know we removed rad and then reinstalled. Hoping all of this is not cause of latest issue:

Car is leaking coolant. Car seems to run fine, EXCEPT a long period of idling will cause overheating. Normal driving does not cause overheat. I notice a coolant puddle in my parking spot, after car is shut off, which seems to be getting worse. seems to be dripping from behind rad (as in, closer to firewall from the rad).

Any other car I've owned.... the coolant puddle when not running is indicative of water pump failure. Is the long idling/overheat also suggesting water pump issue?

Anyone replaced water pump? Always an ugly job on the easiest of vehicles, what is it like on these?

Any other trouble shooting I should do before diving into this repair?

THANKS!!

 

'05's are well known for thermostat leaking - it's on the top right side of the engine. But that shouldn't cause overheating, unless your coolant level is low (which could be if you're not refilling it as it leaks.)
Water pump is a big deal, but if it's not overheating when driving, I would not suspect that. More likely a failed low speed fan resistor. You can replace/bypass the resistor, or just replace the fan.
If I saw those symptoms, I'd replace the fan, and the thermostat/gasket.

 

+1 for what Eric said.

More than likely the low speed of your fan is not working.

Motor on!

 

hmmm, thanks very much. Car has around 120-140K miles and is 10 model years old, so I thought water pump might make sense to be going by now. Would love to discover I'm wrong because it looks like a big ugly full day job...including pulling the intake manifold, injectors, etc..

Would the thermastat gasket leak when sitting, or only when running? It leaves a puddle when sitting, which has been getting worse.

Overheat is only when idling. Pelican parts site suggests getting up to operating temp, squeezing upper rad hose and trying to feel for pressure. If so, pump is probably circulating. I will try that one.

What is the thermastat gasket and resistor job like to do? Where can I buy resistor part, or fan?
THNX!!

 

The thermostat housing/gasket usually leak when car is not running. I would find a puddle under the car in the morning after the car sat in garage all night. You should be able to look down at the thermostat housing to see indications that it is leaking. Look for puddled coolant near the housing and/or white residue from dried coolant.
However, as stated that leak should not cause overheating unless you have been letting the coolant level run very low, from coolant leaking out.

 

hmm, only overheats when sitting in line and idling, so perhaps the combination of no low speed fan while idling, and leaky thermastat to cause the pooling... is my issue. I don't think coolant gets that low, pretty sure overflow bottle (or expansion tank...whatever people call it) gets topped up regularly.

It is my brother's car, I just get the luxury of fixing it.

So how much stuff needs to get pulled apart and removed to gain access to fan and thermastat. I vaguely recall a long time ago when his Power steering pump and pump fan wouldn't shut off, he could hear a fan running and it would kill the battery. He self-diagnosed a defective rad fan, so we replaced it, and/or possbily a small electrical resistor looking thingy (??). I recall pulling off front bumper to gain access, and swinging rad out of the way with AC lines still connected (?). This was a long time ago.

I'm just wondering if perhaps we already tackled the fan and resistor part. Or maybe it's gone again?? What sort of fan activity should we see when it's sitting idling? Fan should kick on and we see/hear it?

 

I do see evidence of leaking on thermostat housing area, lots of dried coolant and corrosion, plus some green too. I call that area left side of engine (driver's side), near air filter box; just below.

I also see the actual cause of leakage and coolant on the ground is where the upper rad house connects to the plastic housing mounted to the rad, on the right side (passenger side). The plastic mount is screwed/bolted onto the upper rad area. I can see dripping there. Can that piece be replaced?

My fan comes on when idling/heating up, so i think the fan must be okay, and the relay/resistor. I tried squeezing upper rad house when warm, but couldn't tell anything from that.

 

Is it item 1 in the diagram? If so it is P/N 17127515500 for about $27.

 

very close, but it's actually the part mounted on the rad that item 1 mounts to.

 

STOP!!
if the car is overheating when siting....then the FAN is not likely running....
The fan will cool the car FINE WITH only The HIGH speed fan on...not ideal...and it will LOUDLY cycle on and off...but car should NEVER OVERHEAT.
Look at the seals on the water pump...might be leaking...
If the car is very low on coolant, you can get a bubble in the cooling system.....
I suspect your 2005 has a 2004 production date...check the driver side door...
If it does, you might have a stuck PS FAN....
That can blow a fuse....and stop the radiator fan...
Other possibilities include a heagasket, or even early stages of a sc gear failure....along with a leak of some type.........

Edit....
See you say you HEAR the fan....so look for the leak...might be a hose...
Look back by the oil cooler....it has a coolant loop....and they sometimes leak...

 

If you look at parts diagram posted above by quickmni, part #1 is a rad hose that clamps onto this plastic elbow, and this elbow bolts onto rad.


this is a different angle and it looks a bit warped. Mini doesn't seem to show this part.


Here is where this part bolts onto rad.


And last..I think this shows my thermostat leak.

 

tried to post pics, but i can't seem to....awaiting moderators approval??

 

this part is leaking:

 

the part mounts onto the rad. In quickmni's post above, part # 1 (a hose) clamps onto this, and this part bolts onto rad. Also, this pic shows it looks a bit warped. Mini does not show this as a replacement part.




Here is where it mounts on upper right corner of rad:



And this is what I believe to be confirmation my thermostat is leaking:


Probably a poor choice of words to say my car was "overheating" when idling. The dummy temp gauge climbs and the fan kicks on and helps, but gauge is still elevated over normal, but not buried in hot/overheat. Just heats up is all.

 

OK...high speed only will result in elevated temp at idle...
And think you need a new radiator....a few folks have tried to fix the elbow... Is ususlly a very short term repair...and it leaks again...

 

OK, thanks for info on the elbow. Shocked I can't buy a replacement elbow and gasket. I found an o-ring that fits. What about slathering RTV sealant and re-attaching? Too easy to pinch or not seal properly? Short term??

high speed only? do you mean fan running high?

I see a couple of rads on ebay that appear to have eliminated removable elbow with a permanently welded aluminum piece, around $140. Like this:
http://www.ebay.com/itm/ALL-Aluminum-Radiator-Fit-For-Mini-Cooper-S-2002-2008-L4-1-6-2ROW-MT-NEW-/251533484234?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2005%7CModel%3ACooper%7CSubmodel%3AS&hash=item3a909060ca&vxp=mtr
Or cheaper versions ($68) like this: http://www.ebay.com/itm/RADIATOR-FOR-MINI-FITS-COOPER-1-6-/261380114948?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2005%7CModel%3ACooper%7CSubmodel%3AS&hash=item3cdb780a04&vxp=mtr
Probably only have the car another couple of years.

 

You could try it...new o-ring might work with some sealent...but I recall at least 2 folks that tried...
Maybe buy an elbow from a member who junked a rad for a different reason...
The all allumuium one on eBay...know one guy on *** (different site) that had the aluminum collector tank crack...so might be replacing depending on if it can be fixed...
Bet the sub $100 aftermarket clone "cool-zone" etc brand(rockauto/eBay/amazon) would get you 5 years plus if not tracked...heck stock seem to fail regularly around 10...
Yup...high speed/fan running full tilt sounding like a plane getting ready to depart...

 

Well then I may go low budget on rad. Sometimes I splurge on quality and sometimes I look at fact OEM failed, and look at how long I'll have item and opt for cheaper.

oops, I wasn't very clear in that reply. I understand the sound of the high speed fan running at idle, what i meant was I didn't really understand your earlier comment, "high speed only will result in elevated temp at idle". If high speed is on, doesn't that cool it down? My temps come down when the high speed kicks in.

 

Oh... and I seem to have temporarily fixed the elbow leak. There is a recessed spot on the rad. The o-ring seal over the elbow slides into this recessed spot. I had an o-ring kit and had to slightly stretch a tight fitting o-ring over my elbow, then re-attach elbow. It fit in and isn't leaking, so hopefully it will last awhile.

I went to local parts store and showed them. They gave me a larger O/D o-ring. I could tell the larger OD was not going to seat into that recess. So i used the o-ring i had.

I felt a combination of RTV sealant and the o-ring would not work. Another option might be to goop up the recess with RTV, then slide the elbow in and tighten it. Hopefully enuf RTV would seal it up. But it seems like if you twist or cockeye it, it could create poor seal and leak.

 

The issue with the temp...
The car is set to turn on the low speed at one temp....then TURN ON the fan to a higher speed at a higher temp......once the temp drops a bit..the high speed turns off...and the LOW should take over...but no low....so car runs 15-20° higher than spec, cause you car expects the low to function...the exact numbers are posted....but just know if the high is the only one working, car is HOT and close to overheat....the standard dummy guage has just a couple spots...
Cold, normal, and overheating.....
The chrono pack DOES show actual temp....but not many cars got it as an option that was sold 2005+ on....

 

ah-hah...now i get it!! So if I check fan when idling, I should see or hear low speed running? The fact I'm getting high speed in the "heating up phase" , means the low speed wasn't doing it's job, which helped get it to high speed !!

Is the fix a new fan assembly, or some other method? Can low speed be bypassed to run all the time?

On replacement thermostat & gasket.... Is aftermarket okay?, or is this something where spending extra $20 for OEM is a no-brainer?

And ZippyNH, thanks for your patience and help. Ditto to the other posters too.

 

You could bypass the resistor...or even replace it for $25 or so....or just get a new fan for under $100.
I'd just get an OEM thermostat for the $20...new gasket is built-in....a few aftermarket places tied to sell them separate and cut the notch in the edge of the thermostat to make it work...
If you start the car, AC OFF (IT HAS A PSI switch than can turn on the fan) after a few minutes the fan should run (take it for a drive....the high NEVER RUNS UNLESS CAR IS RUN HARD)and then idle...low speed fan is pretty quiet, but you can see it run...and feel the air blow....car should be able to idle indefinitely with the low running....
If it goes off/hi....you have the low burnt out...
Should see. Off....low...high....low........never off...high...off....
Doing something with the fan is kinda important....many folks find they have a fan issue when the ac fails....it is safe to assume (IMO) the lack if the low speed fan and reduced airflow cause the ac to run at higher psi, wearing it out, and causing pump and/or clutch on it to fail...

 

IF my fan works on low, is it possible the thermostat replacement might help (doubting it??).

I recall replacing an electrical part a few years ago, related to the fan. Do they just not last? I recall it was quite corroded looking, and it was a common failure on these. I thought the replacement was improved. Very vague..will have to check records.

 

Thermostat helps if it is bad or leaking....they don't last forever, but if it works and is not leaking....
Hopefully you found the leak on the radiator....low coolant will cause an overheat every time....
If the fan is good...its good..lol..
Not aware of any "factory" replaceable parts on the radiator... All fixes are homebrew...only factory fix is to swap the unit...heck cause the labor needed to change the resistor, fixing might ( if you value your time very low..fixing a part gets you it remaining life)make sense if you diy it, but to pay a shop when you can get an aftermarket fan for under $100 is a waste of $$ IMO....
Maybe the part was a relay?

 

IMO, no way the high fan should come on in the 'heating up phase'. Mine only comes on when it's really hot and I'm sitting in traffic. I had the patience once to wait for it to come on in the driveway, but it took ages.