Hello. I also suspected that the engine did not reach operating temperature. My garage did not believe it until I used the secret OBC menu to read out the coolant temperature. After 30 min. at idle, I could read 72 degrees Celsius, and once I started driving the car, the temperature dropped 10 degrees Celsius. I got my garage to order the main thermostat and EGR thermostat for me, and then I changed it myself at home. Flushed cooling system at the same time and used the G48 glycol that would fit my 05 '. 525dat. The job took half a day, but with coffee, Spotify and gas stove in the garage it was a cozy job. Took some pics if anyone should be interested doing the job.

Now the operating temperature much more stable, achieves 88-92 degrees Celsius, but the engine still uses a long time to get warm. Consumption is also too high, rarely below 11/10km. The car does not have auxiliary diesel heater. The car lives in western Norway.

Many thanks to you guys here for good information regarding engine running cold and how to change the main thermostat and EGR thermostat.

My next job will be to clean the dirty intake manifold and the EGR mixing valve(?). Mixing exshaust with clean outside air into engine should have been forbidden.

 

Pics would be good, especially for the main stat job

 

I have problems with uploading a 900kb PDF file with pics. I will try again tomorrow.

"Replacing EGR- and main thermostat M57TU_2.pdf

Upload Skipped (Error IO)"

 

Replacing EGR- and main thermostat M57TU_2.pdf

There we go:-)

 

I have also 525d e61, situated in Estonia. I changed the main thermostat but also it takes long time to get engine right operating temperature.EGR should be fine. Generally the outside temperatures are 0-10C below minus. After longer run, it is getting 88-90C, but it takes for excample 20-30 km highway ride 90km/h. Urban condition it takes more than 20 minutes to get operating temperature...

I wondered, is the 525d so energy efficent, that this kind of warming time is normal?

 

If I turn off the heating inside the car, then it takes less time and it stays at 88-90g.C, but with AC in auto mode, temp. set to 22C, cold outside and low speed, engine temp. is only 70-80C. I will check what the position of the shutters in front of radiator is when running the car. There is some sort of magnet device holding it in position. I think they should stay closed until engine reaches operation temp.

 

Another satisfied customer
BMW 525d touring with very high intakes, after some improvements discovered that the temperature of the coolant is very low, about 60 to 70 degrees. sometimes 50 degrees.
I changed the main thermostat but it was almost equal: (
After reading the 22 pages of this topic I realized that the problem was the EGR thermostat.
Yesterday my mechanic changed the thermostat (it was not easy at all) and the temperature finally reached 88/89 degrees in progress.
I do not have ideas of improvements in consumption for now.
Thanks to mini_me and all others who helped

I'm from Portugal
Thanks

jmcdpereira

 

Really? I can change the EGR stat in like.. 15min

 

Not in my car. (special one... lol)
I have no space to push the vacuum hose of the way.
I think the vacuum hose has one centimeter more than it should and it is very difficult to remove.

jmcdpereira

 

Just unscrew the single screw where it's connected to the vacuumpump. Then pull it out and push it out of the way. Done