kobolt60

Mine is still runing hot but there is a change since I installed a pedal box.

Its now pretty much runs on 97-99 degC, its winter now around zero so perhaps thats why

😎

soluon

A second case succeed!

My friend's X5 N52N have rought idle and I have confirmed low fluctuating temp 77 - 84 oC. He has performed the Italian tuned-up in about 40km distant.
Perfect temp immediately: 99 - 108oC in the city, mostly 99 w/ AC ON and 105-108 w/ AC Off, 93-95 w/ hard drive and back off to 80-85 w/ WOT. Still perfect after 3 days and several complete cold starts, and the engine is silky smooth w/ or w/o AC. He is totally satisfied now!

​​​​​PS: my car n52n is still in perfect temp behavior. It is 25oC in Hanoi for your reference.

kobolt60

Could be that driving too less revs can affect the DME performance.

since I installed Pedal box I rev the engine much more still runing hot.

http://www.pedalbox.com/en/product/response/

T

soluon

I have the conclusion for this ghost...
The problem is carbon build up in the combustion chamber. I do normally run on ron95 gas, but with the carbon build up so the engine think it run on lower grade gas ( octane degration) because it is easier to have detonation. My car have little and very short pinging on light acceleration, not noticable with windows up. Last weekend I have forced to run on lower grade ron92 gas and problem reappear: 77-84 oC happened when I tried to accelerate the car. I changed to Ron95 with octane booster after the trip and temp back to normal 99-109 oC when you drive normally.
With excessive carbon build up in combustion chamber or low grade fuel, the DME reduces engine coolant temp as much as possible to reduce temp in combustion chamber to prevent detonation, which is dangerous to the engine.
Italian tuneup is a method to decarbonize the chamber. Running the engine hard reduces and prevent carbon build up ( like pedal box...).
Hope the problem is finally fixed....I will update more...
Best regards.

Musab Aljbory

I have same problem with my e60 525xi, it started after a regular coolant flush, my car has no drain plug in the radiator so i decided to remove the heat exchanger hose and drian the coolant. After unpluging the heat exchanger hose there was no coolant coming from the radiator so i inserted a screw driver into that hose plug and open it (i though there was some dirt blocking it)
New antifreez filled the radiator and did bleeding the right way using the gas pedal but since that day i lost the heat and the car wont heat up wuickly as used to be before. After reading this topic am sure that heat exchanger hose is the problem. I will block it tomorrow and hopefully it will resolve the problem.

Don dario

Hi Guys




Im allso convinced that a somewhat DME problem and driving pattern!


There is nothing new regarding my temp. problem!!!


Are there any updates from you Guys?




How long time does it take for you Guys to get from Cold engine temp to the 74-82 degreese (mine takes about 20 min in outside temp at 0-10 degreese)


Best Regards

poisike

I'm 99% convinced that in my case it's DME that holds it in high power mode (80C).
I had a vanos error (2A99) yesterday and guess what happened? Temp got up to 93-97C and stayed there until I turned of the car. It appears it entered reduced power mode because of the error and it could raise the temp without any problems. After I restarted the car, it was stuck at 80C again.
I have confirmed same behavior when removing the thermostat plug. So clearly it's not a probleem with heat exchangers or thermostats in my case (I have replaced all but gearbox heat exchanger/thermostat).
When I reset all engine adaptations some time ago, it also got up to 93-97C for a few days and after a few days it got stuck at 80C again. One interesting thing is that I followed the adaptation reset procedure I found using Google, it suggested driving with up to 40% throttle at first and I did that. But reading this topic I started thinking that if DME doesn't see more then 40% power then it probably assumed it was max power and that may be the problem why it's in high power mode now all the time. I will do another reset when i find time...
Only other thing I can think of is the fact that my car seems to be coded for high power from factory (I confirmed that in DME coding, this setting can't be changed after the engine has run for 10h). But I'm not convinced that this coding should make it run in high power mode all the time, except at speeds higher then 96km/h.

Also need to find out what caused the vanos error during cold start... No other errors are stored and that's strange. Usually with vanos problems there are multiple errors.

About warm up time. It's about the same as you. At outside temp 0C it takes between 15-20 minutes to reach 80C. I have a feeling that it used to warm up faster, but I newed timed it before the problems started.
In my case the only thing that can cause slow warm up is gearbox heat exchanger/thermostat. I have already replaced oil heat exchanger and main thermostat. But based on the what I have seen with my testing, I don't see this issue being related to the engine being stuck in high power mode.
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soluon

Hi all,

I highly recommends you guys do some kind of real de-carbonization (not the kind of a bottle in a tank or spray in the intake...)

My car and friend car still run at the perfect temp 99 - 109oC.

After many trial, I think we could replicate the problem like this: At the cold start and AC OFF, idle the car until it warmed up. Most likely, you will get the temp raised to 96 - 99oC. Then drive the car slowly along a long wall with driver window down, then moderately accelerate the car and you will hear a little and very short pinging for about 0.5 second. You can not hear this ping with the window up or with hard acceleration as the engine sound is too loud. After 2 - 3s, you will see the temp goes down very fast from 96oC to 80oC in 5 to 10 second. You can also replicate the ping and temp down with going up a ramp in high gear (4 or 5)...The DME detect ping/detonation then immediately reduces temp to protect engine.

With Vanos error, the DME will disable Vanos and switch to very conservative valve and spark timing leading to very save combustion -> can not detonate/ping -> higher engine temp. After your restart, if the error is not present -> engine will run highly advancing timing for both spark and valve -> pinging/detonation -> temp back to 77 - 83 fluctuation.

I and my friend all have done piston soak procedure with chemical to remove carbon inside chambers and have perfect smooth engine for almost 2 months, can not hear the pinging in any situation. With AC on temp is 99 in stop/go and 103-104 in highway. With AC OFF, temp stays on 105 - 112oC. I rarely see 85oC now, only with WOT for more than 5s continuously. I also notice that the temp is changing much more slowly, maybe 1 degree in 2 - 3 second not like before when it get down from 97 to 77 in 5 - 10 seconds. The engine get from 20 to 62oC within 5 minute, to 82oC within 10 mins.

Hope this help.
Best regards

kobolt60

Im pretty convinced that my engine DME is operating as it should.

For me I probably suffered from granny driving and since I starten to put some more throttle on and also installed the pedal box, engine operate to 99 % on around 100 degC.

With the pedal box I throttle much more time over 60 % of WOT and I love this simple device which make driving fun. It probably cleans the cumbustion chambers etc and I will throw in a bottle of RedLine ST1 next tank.

With very smooth drivning I reach 90 DegC in about 10 minutes with ambient temp of 4 Deg.

Torgny T

poisike

Update on my issue. It appears to be fixed now.
​​I did another engine adaptation reset. After that I let it get up to 100C and then WOT from 0 to ~100km/h a few times, so it can learn the max load parameters.
I did a engine adaptation reset some time ago already, but that time I followed recommendations I found on internet that you should not give more then 40% throttle after adaptation reset. I believe this caused the DME to assume that's full load.

Now my temps are (with climate control off, to remove as many variables as I can) ~110C in city traffic and ~103C at 90km/h. If I accelerate it drops to ~95C for about 30 seconds and then rises up again. It has not fallen below 90C at all, but I have not pushed it really hard either.
Oil temp stays at ~102C
Gearbox at 85C.
Warm up to 90C takes about 11m.
Outside temp was 5C.
So it appears to work as it should now.

I also discovered that I can see in inpa when it opens the DME controlled thermostat. To my surprise it appears it's not only on/off control, but DME can actually open it as much as needed. One thing that puzzles me is how does this two part thermostat actually work. It has a regular thermostat too and I don't understand how the DME controlled thermostat can give more coolant flow even at 110C when the temp controlled regular thermostat should already be open? But this is how it works. Is the DME controlled thermostat on a different hose?
Inpa can also show water pump speed. I turned off the climate control for testing because when climate control is on it forces the water pump to always work at about 60% and because of this I couldn't see how the cooling system works exactly.
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