mikael

I couldn't find any second thermostat on the 545, so I ordered a new main thermostat and changed it myself today. The old thermostat was indeed not closing. Temperature is now stable at 102-105?C when hot, and it gets up to temp alot faster. Can anyone confirm these temperatures as normal on a 545?

Replacing it was easy, basically just diconnect the electric connector, remove the metal wire clip securing the hose and remove the hose then unscrew the three bolts holding the thermostat to the pump housing. Of course coolant will pour out so be careful if you're doing this on a hot car. Mount the new thermostat in reverse order, fill up coolant and run the automatic bleed program described here (I could not find any manual bleed valve on the 545, anybody know if there is one?). Took me about an hour and the thermostat was 60$. The BMW garage wanted 600$...

I'm not sure this is a fix to the "increased emissions" warning the original poster had, but it's easy enough to check your coolant temperature using the hidden OBD menu described below (taken from this post). If it's low the thermostat could be a likely cause.

1) Turn ignition key to position 1 (Radio)
2) Press and hold Trip button until 01.__ appears.
3) The car?s chassis number will soon appear below this ? add the last five digits together, and remember this total for later on.
4) Press and hold Trip button to get 01.__ again, and then keep pressing the Trip button repeatedly until menu ?19 Lock On? appears
5) As soon as 00 appears below it, immediately keep pressing the Trip button until this figure reads the same as the total number of the last five digits of the chassis number which were added together previously
6) Wait momentarily until menu 01.__ appears, and then press the Trip to get menu 07.__, and the temp. will appear.
If the car is started from this menu, you will get a continuous temp. read-out until the ignition is switched off again.

vesil

I don't know about 545 but my 530i keeps temperature between 95-99?C. I have investigated both TIS and WDS but I did not find the official info. I guess that BMW is engineered like that, but the most typical thermostat value in petrol cars is something like 89-94?C.

mikael

Thanks for checking. I seem to remember having read that the V8's normal temp is 108?C, but I cannot find where now. Maybe I should make a thread asking fellow V8 pilots to check and post their engine temperatures.

Btw, the 545 thermostat seems to be electrically controlled (no temp stamped on it either).

VW2545i

I've tried to find anything on how to replace the thermostat, but nothing. Does any one have pictures or a step by step. I've run the Diag tool and I have a bank not getting up to temp.

Sean

mikael

There's a step by step explanation three posts up...

"basically just diconnect the electric connector, remove the metal wire clip securing the hose and remove the hose then unscrew the three bolts holding the thermostat to the pump housing. Of course coolant will pour out so be careful if you're doing this on a hot car. Mount the new thermostat in reverse order, fill up coolant and run the automatic bleed program"

If you read this while standing in front of your car with the hood open you'll see clearly what you need to do, it really isn't difficult on the 545.

This is what the thermostat looks like (part #7, pic taken from realoem.com here):


On this image you see where on the engine it's located, centrally between the banks:

Robbage

In the diesel you'll clearly NOT see what needs doing as it is hidden behind the Egr cooler. It is errr somewhat awkward and laborious on the diesel to change.

Not wishing to hijack the petrol thread but for diesel operators you really do need to read the diesel one before taking this on. Not sure about the petrol one but the diesel has 88C stamped on it, a petrol traditionally runs higher than this i am pretty sure...

Anway back on topic...

VW2545i

Thanks that was the picture I needed. When I asked at my local parts stare they were trying to sell me the pump and the thermostat. I'll take care of this over the weekend. Thanks for the pic mikael.

Sean

fuji0030

Thermostat calibration is a term related to thermostat repair. ... Check out the next section for tips and techniques on how to replace a thermostat

_________________
Thermostat

phocker

i changed the thermostat out with a new one, apparently the defective one was stuck open.

it's not a complicated job, too bad I didn't take note or any pictures. But I remember I used a wrench with an extender to loosen it up the 3 screws on the thermostat. You also have to move some tubes which will be in the way. Once you access the thermostat, you unscrew a few bolts and unclip the hose.

hope this helps

evo42

I did this tonight. Do I need to have the CEL reset as its still on?