Hey guys my 2003 r53 with 80k miles on it just got the 15% pulley as well as some new spark plugs and they also fixed the gasket cover leak. After driving for a few days the temperature light went on. I went to my mechanic who has a car reader thing and told me the car was overheating. He checked the coolant and saw that it was low but couldn't find any leak. He put new coolant in and the car was fine for a few days but it is now overheating again.

Any help would be appreciated!

 

Check to see if the fan is functioning properly, get the car up to temp, then cut AC on full blast, the low speed should come on constantly. If it just cycles the high speed on or off you have a bad relay or resistor.

 

Yeah the fan is always on. It's super load and annoying. When I park the car and turn it off the fan runs for 10mins

 

No that's not what I mean, but that sounds like it is bad. Let the car get warm, normal running temp. The turn ac on full blast, as cold as it can be, if the fan cuts on and off then the low speed is dead.

 

Was the coolant low again when it started to overheat again?

 

High speed fan kicks in at 232*f. This is a symptom more likely and not the problem.

 

What is the coolant level in the bottle now. When cold remove cap and point a flashlight in there to check. If you have frequent top offs in short periods of time and not finding evidence of leaks, the system needs to be bled properly.

 

At the very least, your low speed fan resistor is shot. That's an easy fix. You may also have a bubble in your coolant system that's causing hot spots. Address this immediately--it can damage your cylinder head. Also check that your thermostat is working well (after running the car for, say, 4-5 minutes from cold start, check that the top hose that runs next to the radiator is hot to the touch). BTW, do you hear clattering from the front center of your engine bay?

 

I betting it's the fan, either a relay or more likely the resistor. I just dealt with this exact issue. New fan overnight shipped from rock auto was about 100.

 

Can you send a link to the part?

 

I believe the op said:

Adding coolant helped initially....So maybe adding more and Doing a BLEED will help and costs nothing, see if that helps before shelling out the $ for something that sounds like its just trying to do its job. ( The fan )

 

+1 ^ That's why I am curious if the coolant level was low again when it began to overheat the second time.

 

Yeah the coolant is low. Just put some more in. It looks like I need a new resovior tank. I think it's leaking through the cap of the of the tank and dripping ontop the metal below it causes steam to make the engine bay overheat

 

The steam is not causing the overheating. But the reservoir is part of the pressure system. If that has a leak then the coolant is under less pressure, which gives it a lower boiling point causing the engine to overheat internally. The steam is not causing the engine to overheat. The engine overheating is causing the steam.

That leak is most likely the culprit though.

 

That's not a leak. The coolant is overheating and boiling over and has nowhere to go but out through the cap. It's a symptom, not the cause.

 

Not on a Mini, that cap should be sealed tight. The reservoir is pressurized as part of the system unlIke traditional overflow tanks

It's literally a reservoir. It's extra coolant underpressure. Not like a regular tank that catches the extra being pushed out.

 

Here's a picture of the tank and what's under it. It looks clear to me that's it's overflowing from the cap? Should I replace the whole thing or just the cap? Also should I get another oem or a nicer aftermarket aluminum one?



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OK. I didn't know that the S is different. The non-S just has a flip snap-on cap and it isn't pressurized.

 

Oh, I didn't know the non s wasnt the same! And to the OP, that depends on what you wanna spend. I'd replace the whole reservoir at the very least. But whether you want to fork out the money for aluminum is up to you.


I'm gettin real sick of the autocorrect changing whole dang words on my phone

 

The seal on the cap may be bad. Check it over and also check the seams around the coolant tank to make sure the tank isn't leaking as well (view image below). Replace whatever is leaking and make sure to fill the system with 50/50 MINI blue coolant.

Cap - http://www.pelicanparts.com/catalog/..._pg1.htm#item4

If the expansion tank is bad, it comes with a new cap (the aluminum one doesn't) - http://www.pelicanparts.com/catalog/..._pg3.htm#item9

Coolant - http://www.pelicanparts.com/catalog/..._pg1.htm#item0

 

The radiator cap is meant to vent the excess pressure developed from engine overheating, similar issue a month ago when my radiator fan low speed resistor shot due to pothole(hard drop) steam will comes out as a relief valve, replaced the resistor from Detroit Auto bled and evacuate the system and everything is fine..

 

It's still a sealed part of the system. It's the same as a radiator cap, it only let's out pressure if it's above a safe limit.

Not the same as a normal overflow tank, which just has a snap lid and is after the pressure cap.