e53 temperature issues - KTMP is much higher than OBD reading

[cz550]

Hello all. I have a 2005 3.0i X5.

Yesterday I hooked up my OBD gauge tool and when the engine is hot it reads around 77 C (170 F). Then I looked at the KTMP (using the dash "secret" menu) and it says 132 C (270 F). The needle gauge on the dash is right in the middle of the range.

Is it possible that my temperature switch is faulty and the computer thinks the engine is overheating, so it is opening the thermostat and not allowing my engine to actually come up to temperature? I'm also noticing white slimy stuff on dip stick and oil fil cap, so I don't think the engine is getting up to temperature. It's not throwing a check engine light.

KTMP 132 C (270 F)
OBD 77 C (170 F)
Ambient -7 C (20 F)

[cz550]

Okay well I just learned a valuable lesson... the KTMP temperature is not correct when the car is off. I didn't know you could look at KTMP temperature while driving (hold right button for 5 seconds), I was using the KTMP menu when the engine was off (hold right button for 2 seconds, then go to key position 1).

So now the KTMP temperature is matching the ODB temperature while driving. It's just not getting up to operating temperature. Could this be due to a thermostat that is stuck open?

[Overboost]

Originally Posted by cz550

Okay well I just learned a valuable lesson... the KTMP temperature is not correct when the car is off. I didn't know you could look at KTMP temperature while driving (hold right button for 5 seconds), I was using the KTMP menu when the engine was off (hold right button for 2 seconds, then go to key position 1).

So now the KTMP temperature is matching the ODB temperature while driving. It's just not getting up to operating temperature. Could this be due to a thermostat that is stuck open?

In the winter months you can find that you have a soft fail thermostat. You never notice it in the summer months but once the ambient temperatures drop it becomes evident and could possible have been failing for months.

That being said, if you have been operating the engine at highway speeds for 15 minutes or more, your gauge should be at the 12 o'clock position. Keep in mind, short easy throttle runs to the market will take longer to warm up in the winter months. If it never gets there after 30 minutes on the road, you probably have a soft fail thermostat. It happened to mine last year.

https://xoutpost.com/bmw-sav-forums/...hermostat.html

[cz550]

Solved! Thanks Overboost! I swapped out the thermostat and now it gets up to 94 C (202 F). Swapping out the thermostat was a surprisingly easy job. Here's the video I followed:

How to Replace the Water Pump and Thermostat on a BMW X5 with 3.0 L Engine
https://youtu.be/HdsxsDNeSic

[Overboost]

Originally Posted by cz550

Solved! Thanks Overboost! I swapped out the thermostat and now it gets up to 94 C (102 F). Swapping out the thermostat was a surprisingly easy job.