Hello friends,

Before you read any further or post, be advised that I did do at least some of my homework and thought the issue with my car was the low speed fan resistor. I replaced the resistor with this Dorman kit sold by Detroit Tuned today and expected it to solve all of my problems, especially since my factory resistor was absolutely SHOT.

However, the mini still overheats, the heater core still does not produce hot air, and I honestly have no idea what the issue is. The only thing that comes to mind is that the car might be low on coolant? I'm going to try and add more once it cools off again as well as re-bleed the system. I'm rather baffled though as I remember topping the coolant off not too long ago and I don't remember ever having a car that needs constant coolant fill-ups. I don't see any signs of a coolant leak or blown head-gasket (though I suppose either could be possible)..

Any help, ideas, suggestions, etc would be really appreciated.

 

Coolant temp Sensor on it ok? Today my dealer told me mine is just starting to corrode and when it fails could cause over heating, not running well to just plain old not starting up or not start untill you try a couple times.

 

Hm. I'll swap it out with the spare one I have.

What does everyone's temp gauge normally read at?

Mine reads just about a hair to the left of the middle tick between 140 and 250 on the gauge (when it's not overheating).

 

since you said that you just added more coolant recently, i'm going to guess there might be an air bubble in the system. that will cause over heating issues and a failure to produce heat. burp the system.

 

On a gen1 car....
Bet you ran low on coolant...
Leaked through the seam on the overflow bottle on an s, the thermostat gasket, or maybe a crack on the radiator....
Then you filled up the coolant...if the overflow goes dry...you need to bleed the cooling system to get airbubbles out....or it will overheat at lights...
Safe to say you DO HEAR the fan...if not...you likely have a blown fuse...pre 2005 mini's have a 5 amp fuse that powers the power steering fan AND the relay that turns on the radiator fan...if tge PS fan gets stuck...the fuse often blows...stopping THE radiator fan from activating...
If all this stuff is ok...then your waterpump could be worn...or if on a s, the gears might be failing...from lack of lube...not nearly as common as folks would lead you to believe....kinda uncommon...unless you read this site...and see how many folks freak out over the possibilities and go ocd over it....
No heat may/may not be related....cooling system should be flushed every 3-4 years....or rust builds up..and can plug it...the heater core is The low point in the cooling system...

 

+1 for Zippy's post.

AFAIK, if your fan resistor is blown your fan will operate only at high speed when necessary, even while stopped - although you won't have a/c while stopped.

My car overheated recently due to lack of coolant - experienced the same things Zippy mentioned. My fan resistor was blown before hand and is still blown now, although I'm back to normal after replacing coolant and switching out CET.

 

Pretty much everyone said what I was going to say. If coolant is low and that you don't do a proper bleeding, air will get stuck anywhere it can. In your case, there could be an air pocket in the heater core, if there's no antifreeze in there, it can't use its heat to warm the inside of the car. As for the engine, it won't get cooled down properly and wil overheat. I'd get the issue fixed asap, it could (if not careful) cost you an engine. Doesn't take a lot of overheating to mess up an engine.

 

i think you've got a bad heater core...check under your left front floor matt...if it is wet, then that's it...pretty simple check...also you might be able to smell something or see a little fog on the base of the windshield.....

 

I would double check the core as well, especially since you say heat doesn't work. When I bought my '06 the overflow tank coolant was filled with rust and then I found the heater core hoses tied off (no heat). I replaced the core and it was full of gunk.