I have an 03 MC that has until just recient never had a problem with overheating... It seems that the only time this occurs is at idle with the AC off if the AC is turned on during the begining of the overheating I can watch the temp gauge drop right back to normal.


1.) (Radiator level is full) (could use a flush however)
2.) Does the ac turn on other fans that blow on the radiator?
3.) Fan is spinning like a banshee when this happens.

Is a flush going to fix this or is it a larger problem?

 

The thermostat could be bad?

 

I would think that thermostat wouldnt change with AC?

maybe I am wrong

 

Both A/C pressure and coolant temperature control the fans speeds. Is the fan spinning when the A/C is off?

It sounds like you have something wrong with the coolant temp sensor or associated wiring. I'm not sure if the gauge on the dash gets its reading from the same sensor that turns on the fan. If there is a separate coolant temp switch, it could be bad. Until you get it fixed, keep the A/C on so the fan pulls fresh air through the radiator.

 

Thanks for the info that is logical

I guess another trip to Chicago land for repairs (living no where near a MINI dealership has its downfalls)

 

There isn't a dealer in Des Moines?

 

nope closest to me is Naperville near Chicago

 

Under warranty, right? i can tell ya what they'll do. Straight out,they'll replace the whole fan shroud assembly and the thermostat.

From what you describe yeah the fan isn't behaving correctly, though i've gotten some conflicting information about 'what' is supposed to happen 'when'.

If the A/C is switched on the radiator fan is supposed to come on, period. Now, whether that is the low or hi speed fan is not known to me.

The low speed fan kicks on when the engine coolant sensor hits 105C, the high speed at 112C? (don't quote me on those exact temps).

What it sounds like to me is that the low-speed fan is not kicking in, but the fan itself works fine. There's a resistor assembly in the fan shroud that may have conked out, very common.

Under warranty? Let them figure it out.

 

Check all the fuses first. from fuse 1-5 then fuse #8 30 amp thats the fuse for the fan. is the fan coming on when the engine gets up there in temp.
there are different circuits in the fan unit. stage 1-2 may be shorted but the final stage is only coming on with the ac.

is the coolant reservior tank empty. if your loosing coolant. The t-stat housing seal may have went bad and starting leaking,thus causing overheating and air pockets to form in the cooling system.

Check these and get back to me.

 

No waranty

Coolant tank is low after about 4500 miles but takes that long and no drips what so ever?

Just changed oil and no foam or radiator fluid I could find

 

I have gone thru 2 fans, 1 stock and a cheaper after market. Both had the resistor for the low speed go bad. I have now added a aftermarket control to turn on the fan rather than letting the car control it. $39.00 for a/m control vs another stock fan. I would not recomend the Taiwan replacement on ebay. I have been tracking the car a couple times and it has been nice that I can change when the fan comes on.

 

update: Fan issue finally fixed after extensive testing.

The 5amp fuse in the main engine compartment fuse box was blown and I replaced it. Fan working in top shape, couldn't be happier

 

YAYYYYYYY!!!!

Now, get out and MOTOR!

 

Hey cool you got it working!

Btw, just as a heads up, if you're in Des Moines, try MINI of Omaha, it's closer than Napierville.