Thermostat Mahle or Wahler

I've had the thermostat on my M272 engine replaced by an indy mechanic. OEM was Wahler, looking at the original the the Wahler I got, the only difference was the spot where the MB logo was on the original, it was grounded out by some grinding disk on the replacement one.

MAHLE was the last thermostat put in her… no issues happened since then to this day, continues to runs fine, no fluctuations in gauge, or overheating. The dealership even started to have that issue with other customers until we switch to Mahle, solve all thermostat issues.

Replaced the new Mahle/Behr one with a new Wahler one, and now it runs at 97° under low load and 80° under high load, as it should, and seems to be fine.

I replaced the thermostat myself. It’s in a pretty bad place, hidden under the intake manifold. It took me about 3 hours to get the job done, had to use a mirror to see the screws. Mine was stuck open so the car in winter time wouldn’t even reach 190 F. I bought an OEM Wahler 07K121113B thermostat from Amazon for like 30$, so far has been working great.

Swapped to mahle and it's good to go.

I installed a Wahler thermostat a little over a year ago and it's still holding strong.

In regards to replacing the thermostat, Id stay away from Mahle/Behr. I just ran through two that stuck open, so far the Borg and Warner from FCP can actually hold temp @ -19C, which the Mahles could not at -10C.

I have the same one in my E53 X5 3.0 and it takes forever in the winter to warm up. I replaced the old one as it was leaking but the new one takes like 10miles to get fully up to temp. If I have a long coast up to a stop the temp gauge will actually go back down.

I just be replaced mine for the low regulating temperature, and the snag seemed to improve, but it will still pop up and the car is slow to hit temp, slower than it was last winter at least.