Alright so my car has felt sluggish for the past couple of weeks which is strange since the temps are finally dropping a little bit here in South Florida. It's usually "fun time" this time of the year lol. The car has also had a strange overheating problem. The first time around it was a little low on coolant so I topped it off with water. It has happened a few times already, the temp is fine while running but begins to heat up at idle. Today the coolant/water overflowed A LOT and the car started to overheat. Shut it down and let it sit for about an hour as I had class. Came back turned it on and it seemed fine, topped off with water again and all is fine for now but the car still feels super sluggish.

I'm going to do a full coolant flush and replace with a 70/30 mix of water to anti-freeze along with a bottle of water wetter. But in addition I'm wondering if the thermostat is not functioning properly and not letting the coolant through, thus causing the overheating issue. May be time to swap out for an M7 thermostat since it's always hot here in South Florida.

I assume the overheating is what is robbing the car of power but worry it could be something else? I was thinking of replacing the coil and spark plug wires just for maintenance as the car has ~64k miles and they've never been replaced. I've read the #3 coil can have some issues on the earlier cars?

Engine mods are intake, 19% pulley, plugs 2 ranges colder than stock and a cat-back exhaust...

 

what year is your MINI?? It might not be the thermostat. First make sure you don't have any leaks. Alot of the R53's have coolant leaks from either the coolant reserviors or thermostat housing. Also, are you sure that both of your Aux Fan speeds are working?? If you turn on the A/C and your high speed fan keeps cycling on and off.. chances are your stage 1 Aux fan is not working. Check those first.

 

It's an '02. I saw the coolant overflow from the expansion tank but I'll check for leaks. How can I check if each individual fan is working properly?

 

^check for leaks using a coolant system pressure tester available at your local autozone for free rental.

a bad thermostat, can cause the car to get hot/overheat. Get it hot enough and you'll warp the head and kill the head gasket (if its not already) so that coolant leaks into the combustion chamber. Fun $tuff.

 

Make sure PS fan is working. Failure can cause major overheating problems.

 

Thanks I'll see if I can swing by today and do a coolant system pressure test. "Hot enough" would be full red on the gauge for a while I assume?

If the PS fan wasn't working wouldn't that cause the PS pump to fail? My steering is fine so I doubt it, but I'll look into it.

 

Where exactly is the PS fan located, drivers side? Car is too low I can't get a good look under lol. But, I do hear what sounds like a PC fan so if that's it then it works. The fan for the radiator/a/c does work it cycles on/off with the a/c on and will turn on once the car is off if necessary. Checked the fuses all good except for PS fan, dunno where that one is located. Under all the others?

Coolant was low again and topped it off. No visible leaks but I'm not sure where every single hose/clamp is. Could be leaking through the thermostat, seems that's a common issue on early models.

Went for a short trip and the temp didn't get above 96*c in the odometer readout (trip button > 19 off > 7.0) ... i had the a/c on and when i shut it off the fan kept running and the temp went down to 94-93 and the fan shut off. I then turned the car off cause my dog was waiting to go inside lol. I read in another thread the slow speed fan should turn on at 95* and the high speed fan at 101*. Waiting for it to cool down so I can check the coolant level.

Seems to be pointing in the direction of a new thermostat, gasket, maybe housing and a fresh coolant flush but I'm no expert.

 

Hmmm ok. I was messing around the with odometer diagnostics readout again and apparently the high speed fan isn't kicking on at 101* like it should. If I turn the a/c on to kick the fan on and then turn it off the fan will stay on until it cools down. But it won't automatically turn on at 101* like it apparently should. Not sure how to correct that problem...

Also, after all of this I noticed the coolant overflowed at the expansion tank a tiny bit but very little. Will check in the morning to see the coolant level, I think the thermostat may be leaking. Gonna have to check it out later in the week, sadly enough, no tools.

But, other than that, is it safe to assume that the reason for the overheating could be a stuck thermostat?

I want to get this fixed ASAP as I'm also finally replacing the worn front control arm bushings with the Powerflex bushings and the worn drivers side wheel hub with bearings. Really want the car back to 100% so I can enjoy it in the somewhat cold weather.

 

We had to replace the fan. We were shown the little part that gets burned up and were told that it's more common here in FL due to the heat. Apparently one of the signs that there may be a problem is a slight shudder that feels like you're going to stall (like when stopped at a light).

 

How much was the fan and associated labor?

Coolant is low once again. There definitely has to be a leak somewhere other than the expansion tank. Will check the thermostat for leaks.

 

I don't remember without hunting for the invoice... and I think it was covered under the one time goodwill warranty thingy. From memory (and of estimate when they thought "we" were paying) maybe around $200? All I remember is that we couldn't just replace the little crispy part... it all had to be replaced.