Car: 2002 MINI Cooper S, 59,100 miles.

I'm an autocrosser, and had some issues with overheating this weekend. After reading a few others posts about overheating problems with these cars, I'm concerned that I may have made a mistake or two, but I'll tell my story and see if you all agree with me on where to go from here.

I was autocrossing Saturday, and since it was above 90 degrees, I switched on the AC while I was waiting in grid. Soon after, I noticed the temperature gauge (stock idiot gauge) had gone up to about the 3/4 level, and immediately killed the engine and popped the hood. Packed up and drove home after it had cooled off, and there was no sign of any unusual activity after that. I attributed it to a low coolant level, and topped it off last night.

I went back up for another event today, and got in 3 runs (7 total, between myself and my co-driver) without having any issues at all, then as I was in grid for my 4th run, the temperature spiked again (almost to the red line), so I immediately killed the engine, popped the hood, and let it cool. I talked to some other MINI drivers, and, concerned that it was my head gasket or water pump, decided to test it once it had cooled off - I took it for a couple of leisurely laps around the campus we were at, with no issues - I figured that meant that the coolant was getting from the engine to the radiator, so the water pump should still be good. I then took it out on a main drag and did a couple of full throttle pulls, which should (to my understanding) spike the temperature if there's an issue with the head gasket. No change at all at that.

After looking it over, we noticed that the radiator fan was not spinning, and visually checked all the relays and fuses according to the diagram, which did not appear to be blown - the connections were good, there was no sign of charring or anything of concern. We swapped a few fuses around and all the other systems continued working fine, while the radiator fan continued to not function. We checked all the wire connections that we could find under the hood, and they all appeared solid (though we didn't have a manual on hand to know which connections we were actually looking for).

The radiator fan can spin freely (tested it with a long screwdriver), so it's not seized or jammed, but it is not working at either speed. Since I'm going to be getting adequate airflow and it was a 60 degree day today, I decided to drive home, and had no issues on a lengthy highway drive, watching the temperature like a hawk the entire way.

At a risk of rambling on too much... I was listening to Car Talk on the radio, where they mentioned that a failed thermostat could manifest itself both by a decrease in gas mileage, and the radiator fan ceasing to function; I have only been getting about 24 miles per gallon the last few fills, but I hadn't really thought anything of it, since I've been driving like crazy since the snow melted, and I knew my air filter was on its last legs.

I replaced the air filter about a week and a half ago, and I don't recall hearing the radiator fan after that, so I'm considering the possibility that I could have knocked something loose, but I checked all the connections around the air box, and nothing appeared to be out of sorts. I also did the spark plugs and wires about 2 weeks ago.

Anyway, does anyone have any suggestions on where to start? And should I be concerned for damage that might have been done by a couple of brief (3-5 second max) overheats?

Right now I'm torn - I'm aware that there are known problems with the radiator fan, and that I'm in the failure range for that part, so I'll probably need one soon.

I'm also considering the possibility that it could be the thermostat itself causing this, since I don't believe the radiator fan malfunctioning would by itself cause decreased gas mileage, but a thermostat issue could cause both problems (to my understanding). However, it's possible that the gas mileage issue is from an unrelated problem, and that it's the fan.

Is there anything I can do to test for one or the other? Is there any information I can provide that will help you help me? Please discuss/advise.

E: Also, I drove it for quite some distance on the highway today after the event with no issues, so air seems to be getting to the radiator just fine. Is it going to be safe to take to work while I wait on parts/repairs?

Are there any how-to/walkthrough threads for replacing the thermostat and/or radiator fan for someone with the self-taught knowledge to do oil, headlights, air filter, and spark plugs, and with common sense and an ability to follow instructions? I couldn't find any, but if they're out there and you know of them, I'd love links.

 

You might also want to check out the PS fan under the engine. On early cars, they are tied to the same fuse as the radiator fan. If fuses are not blown, it could be a bad fan motor but that seems unlikely.

 

This is a really good book that will help to solve your problem; I have also posted some information on this forum on how the fan works! Do a search for radiator fan.

Good luck.

 

Bump for a small update - I called my mechanic and I'm going to send it to him for this one. Without the time to wait for parts and manuals to get shipped in, or the time to learn to take apart the front of my car to do this myself (and without someone to supervise me to make sure I don't make some kind of catastrophic error), I'd rather just pay the guy. I'll update when I know what's going on further, but I'm expecting a solid $500+ repair bill if it's the fan unit.

 

The green relay on the radiator fan; not sold separately.

 

Or better yet get it to a MINI dealer and let them fix the power steering fan/rad fan problem under warranty/TSB.

 

Let us know what the issue was. Sorry to hear about your troubles... Mine was quickly spiking like yours but my overflow tank was leaking and I was extremely low on antifreeze. Since replacing the tank, and topping it off, I've been fine.

I autox'd this weekend 6 runs total, and my guage never once went beyond 1/2. Now my aftermarket oil temp guage was telling my that I was sitting at approx 275! Which one's right, who knows...

 

I was having the same problem on my 2003 MCS. Two of the relays have been replaced with the new ones and everything seems working fine for last couple days.

I checked the circuit diagrams of the cooling fan, it seems the problem can only be caused either from the relays or the main computer.

 

2002, no warranty.

It was the fan, alright. It's getting fixed, now.

 

Actually MINI is obligated to replace the faulty wiring no matter the mileage.

 

If it's already been repaired and I was unaware that this was a TSB, will they reimburse me for it? Ugh.

 

It doesn't do anything to the radiator fan. It just has an updated wiring harness so the radiator fan and power steering pump fan are not on the same fuse. Thus if the PS fan stops working it doesn't cause the rad fan to stop also.

 

Do you have the TSB # ?

 

Antifreeze level - these damn cars should really have an antifreeze/coolant sensor in the expansion tank. Cheap A$$ BMW/MINI. The cap also vents so don't overfill. So check your coolant level regularly.

I'm assuming you're referring to the gauge in the Chrono Package... at 275*F it should be a little above the 3rd mark. Is your aftermarket temp gauge hooked up to the OEM oil temp sender or does it have its own? If different and at installed at a different location, naturally it will have different reading.

 

I don't have the number, but the dealers should be willing to check and see if this was done to a car.

 

And the repair's done. Changed the oil and there didn't appear to be any coolant in it, so I'm hoping the head dodged the bullet.