Hey everyone, I have been experiencing some coolant leaking recently ('06 MCS). Every two weeks the car had been about 10-12oz low on coolant, which wasn't a huge issue but something that I just couldn't track down. Well today I was changing my oil and noticed a good amount of coolant around the lower shield.

I removed the lower tray/shield and found a massive amount of crud/coolant caked around the front of the engine below the supercharger. I am trying to figure out where it might be coming from...

My first guess was the water pump, but I'm not sure if it might be the thermostat. I ordered a new t-stat in hopes that it might be the cause (mainly because I'm hoping it's not the water pump), but couldn't find enough similar threads to confirm.

Has anyone had a problem like this? Sound familiar?

 

On second read I don't think it's really qualified as a "large" leak in that no coolant is actually hitting the ground, but it is definitely well into the "class III" department given the giant globs of congealed coolant I cleaned off the engine.

I have been replacing the coolant for a few weeks now simply because it has been too cold (no garage) to work on the car and I haven't had to make any long drives. So I am assuming the coolant has just been dripping into the same spot and collecting road grime at the same time.

 

thermostat housings leak often.

 

I'm hoping that's what it is as the water pump sounds far more complicated. I'm going to replace the t-stat whenever the part comes in this week.

 

The thermostat housings are ok, it's the gasket that leaks.
I'm not sure if you can buy the gasket alone or if you have to get the thermostat also.
Have had very good luck using Permatex gasket seal on water pump, thermostat housings etc.
Just an idea.

 

The MINI T-stats come with a new gasket and both are only available from MINI unless you buy a 180* stat from M7. Gaskets are not sold anywhere separately. New ones are whiteish color. Old ones were a brownish color.

Check from the top of engine bay and exaimne the area where the thermostat housing flange bolts up and look for signs of leaking such as a formation of crystaline like substance.

 

You said in front of your engine, have your radiator pressure tested. The tanks are made of plastic and will leak. I had that problem ---

 

Sounds like the water pump weep hole is over active, in other words the inner seal is wasted. It is possible to be leaking from the water pump block O-ring, but my money is on the water pump weep hole.

 

I am assuming the fix for this would be pulling/replacing the supercharger assembly?

 

Yes your assumption is correct.

Jeremy

 

Damn.... I think my Mini is slow pissing at the same possible spots too. Only at 37k, this is a joke. Does MINI stand for mini-quality?

 

With a little more research it looks like just the water pump and seal need to be replaced and not the entire supercharger assembly. Does this sound accurate? If so I'm going to order the pump from WMW and give it a go next week. Nothing too difficult from what I've read. Pull everything in front of the engine, replace pump, reinstall. Simple enough

 

To be fair I have yet to own a car that didn't have some common problem that was near catastrophic, but well-known to enthusiasts. No truly good car can be trouble-free, then it's like it doesn't have a soul. A water pump that's terribly inconvenient to access, but prone to self destruction? Sounds par for the course. At least the car has enough flavor to still entice a large cult following with a wealth of information. I'd rather have that than some beige econobox from the other companies. Could you imagine having to drive a Toyota Corolla every day?

 

Mini does have soul... but modern engineering on simple things like a gasket or O-ring shouldn't be so difficult to figure out.

My '81 Audi 4000 didn't get a new H20 pump till ~200k-mi. My 24yr old Porsche 944S is still on its original pump (125k-mi). And my daily beater '01 VW Beetle had its original pump replaced with the timing belt at 105k-mi and again at 175k-mi.

My Mini is definitely a whiny little prima donna!

 

So follow-up on this. I got home today from work and saw a small (about 1") puddle of coolant beneath the front of the car and small droplets of coolant around the lower splash-guard. I inspected around the area of the thermostat and couldn't see any indications of moisture whatsoever. I tried to see the water pump, but it's simply too hidden by the intake manifold and radiator. From what I could see it also appeared dry, but the lack of anything from the thermostat has me more and more convinced that the "leak" is coming from the weep hole in the water pump as a result of a blown seal.

I have a weeklong vacation coming up the week after next and if it's decent out I'm going to pull everything off and see if I can't replace the pump/seal. From what I have read it doesn't appear that it is absolutely necessary to remove the i/m and s/c, just pull everything off of the front. It also seems like the Mini is built like the older (MkI-MkIII) VW's in that the front is not part of the frame of the car and can all be removed.

 

So final question:

This may sound really stupid, but the water pump can be replaced without replacing the entire s/c assembly correct?

 

Yes 3 bolts and it's free from the blower. I'd inspect the water pump drive oil and gears in the *** end of the supercharger along with the snout oil level. You just need 1 bottle of GM/eaton oil(most GM dealerships will have it in stock) and some anaerobic sealant.

Jeremy

 

Sounds good to me. Now that I am learning about "service mode" this should actually be pretty simple.