Pistratoaie

It's starting to be the case of that's just how the N52's behave??? Although I swear my car was working much better before I had to change radiator and hence mess with the cooling system. I've tried turning off AC/heat and while the engine warms up, I still can't get to 90 unless it's above 28 degrees (Celsius) out and when I switch the heat on... its just air, not exactly hot (tried on every combination of fan output, heat, etc possible).

But how did your car start with the problems Alexander? just after thermostat change? replacing it again might help but it didn't for me. do you get heat in the cabin when driving and warmed up?
I sort of refuse to give up and accept that's just how they are meant to work, knowing it was considerably better 4 months ago!!! just running out of ideas, and money

alexanderxvi

Well I've had the car for 1.5 years bought in March(it was cold, I'm from Canada). When I bought it radiator was leaking so it was replaced right away under warranty. Temperature was fine, car warmed up really fast. Then about 6 months later when it started getting cold again I noticed it took longer to warm up. Then I noticed that if I turn off heat/ac it warms faster/higher. I changed my thermostat because of this, but it hasnt changed at all. Same problem. My mechanic couldn't diagnose it, except that MAYBE its a faulty stat. Right now it got a little worse if before by turning off heat/ac I could get it to 100C, now it just stays around 75-80C regardless if the heat is on or off or if the weather is cold or hot. I'm on the fence about changing the stat again as I dont have the extra cash at the moment but I think I will do it once I go change my brakepads soon. No other car I had behaved like this. Even my 04 X5 with m54 engine didn't do this.

alexanderxvi

Also I do have heat when the car is warmed up, but for it to warm up the heat needs to be off. Its kind of a bitch since when its cold windows start to fog up way before the car is warmed up.

Pistratoaie

Those are almost identical symptoms to what mine is doing. Straight after radiator change everything went downhill. Like you said, it's only really an issue in winter because that's when heat is needed. Mine was sitting around the 75-80 degrees for the last 2 months as well while it was cold, weather picking up here so haven't relied on heat anymore. It's a risk getting the thermostat because it's no guaranteed fix this seems to be an issue elsewhere, just no-one seems to know where or what is going on.
You're not wrong about no other car behaving like these, special cars
I'm still researching and testing things, it's going to the dealers hopefully by end of year with a few requests and going to open a case with them to see if they've got any ideas

alexanderxvi

Good luck with this man. If you ever find the problem please post it here. It might be some time before I change my thermostat again, but I will tackle this issue again. If I ever fix it I'll post it here.

kobolt60

I did some cleaning of the Vanos solonoid powerplugs because I got P0012 this morning (realy rainy weather), anyway I disconected the plugs for the fan switch and the rad coolant outlet temp sensor.

Long shoot but will take a test drive to Falkenberg and back to Väröbacka (120 km) ...will keep yo posted!

sanjsanj

E60 diesels are NOTORIOUS for failed thermostats... there have also been a small number of cases where if both thermostats still doesn't cure the problem, changing the gearbox oil cooler (there's a stat in it too) has helped.

Non genuine diesel thermostats are also known to fail within a short amount of time so if you didn't get your part from the dealers that might be another cause.

I've only read of one case where a brand new main thermostat from the dealer was faulty from the outset.

kobolt60

Still runing cold so only way to find any cable ruptures will be to measure all components...thats over my head.

Found a document, look at page 3...problem is here somewhere...

http://prodcds.bmwuniversity.com/lib...System.qxd.pdf

kobolt60

Drove 75 miles after trying to pull out the fan switch, radiator outlet sensor, and both individually .. not much difference except that the fan does not regulate between 76 _ 84 degrees .. and at idle it goes up to 98 degrees but as soon as I start driving ... down to 80 ... no error codes, whatever ...

Tested on the highway to drive below 95 km / h ... 80 degrees ....> 95 km / h ... 100-103 degrees. Drove in 120 stable at 100-103 degrees, disengages and rolls for about 30 seconds in downhill down to 100 km / h ... little cooling to type 98 degrees but quickly up to over 100 when I increase the throttle speed. If I reduce speed below 95 km / h at idle reduces the temperature to 80 degrees .... same thing if I reduce the throttle to below 95 km / h as the temperature decreases instantaneously ... what is it that is speed related ??? Is there any gadget, hose or anything else that is affected by the wind in 100 km/h ??

Luckily I have a lot of spare time .. Will try and cover for "kidneys" and see if it then gets hot at all ... before I pull the thermostat connector ..

Pistratoaie

Definitely keep everyone updated, as or if things develop
I'm waiting for new Vanos Solenoids to arrive, mine are gone too. Then I'm doing transmission pan and oil change. Mechanic suggested the possibility of these things acting as failsafes... or the battery being something to consider. And, for the first time in 3 years of ownership the car took a little longer to turnover than usual, although it was a one-off.

Great document find Torgny, could the data-maps for road speed be affecting your stat? page 18 and 19 would suspect faulty management, that's what I'm going to get the dealers to look at in mine, because I have no idea if I can access those maps. Anybody know how to access these data-maps??? If you cover grill and it still doesn't heat up then it's definitely not wind/air related (yours doesn't have those shutters right?) curious to see what would happen.

Sanjsanj I've been reading into the diesel versions more than petrol lol, I'm guessing it's about 1 to 20 ratio of petrol to diesel questions of this nature in forums. Since the petrol only has the main stat, should be easy picking, apparently not. I'm still contemplating whether to do oil cooler, I'm leaving that for after inspection of wires and software.