2000 328ci E46 M52, Engine Overheating.. Help!

[Michaellane72]

BMW dealership diagnosed a fault with the radiator (warped at the bottom) said I needed new radiator and thermostat.

Have just paid an independent BMW repair center to replace and yet they are now saying the engine still over heating at idle...whic was the original fault.

Is it possible that the fan isn't working properly and not therefore cooling the engine? also happens when the aircon is turned on..

Any ideas..

Cheers.

[drz]

Does it overheat when you idle and the A/C is not turned ON? Try turning on your A/C and then going out and check if the electric fan is coming on. It should turn on whenever teh A/C is running, regardless of temperature. There is also a temperature sensor that connects to the side of teh radiator that sends teh signal to turn the fan on and at what speed (low speed/high speed).

[TRuckee]

Make sure that the system is purged of air. It takes a while to get it all out of the system and any air in the system will cause it to overheat. It's not hard to bleed and get back to me if you're interested in tips on how to do this. Tom

[Michaellane72]

Thanks guys..the independant garage have said it needs a new fan assembly ...which I have now paid them to do.

What pisses meo ff the most is when i originally took it to the BMW dealership...saying " i think my fan isn't working properly" they said it was and that it needed a new rad and thermostst. This is what i therefore instrcuted the independant guys to change ..which they did before identifying the fan problem however..they said that theres nothing wrong withthe original rad. BMW said it was warped at the bottom...but its not...now clearly it looks to me thatthey were trying to rip me off...not expecting me to take the car else where to get the work done...does this sort of thing happen often?

Cheers,

Mike.

[witeshark]

If you believe the dealership was trying you, I think you should notify BMW.

[Nichola67891]

Did you mix the BMW antifreeze and normal green antifreez? if so the mixture of the two makes either a grey or a yellowish colored sludge. i know because this happened to mine. it eventually blew the head gasket. i took 7 pounds out of that crap out of the engine myself. not a private mechanic. alot of dealerships will deny that this happens, but it does and you will see alot of 2000 to 2005 bmw's with this problem. now what you can do is have the system purged. but there are areas that cannot be purged. i.e. the heater core supply line. you will have to take off your air intake manifold to get to this but there should be two plastic line comming of the engine one off the back of the water pump housing and one off the cylinder head then they connect to rubbere hoses one goes to the radiator expansion tank and one to the heater core or the heater control valve you want to either replace these or wash them out thouroghly. and this with the system purge and a proper bleeding of the coolant system and use of the BMW antifreeze(which is blue and has a higher boiling point than the standard green stuff) this should get you back in business. i took alot of pictures of the process and the sludge if you would like to see them let me know. good luck