Thermostat Wahler or MISHIMOTO

In the past and up to several months ago, I’ve always gone with Saleri (Italy) pumps and Wahler (Germany) thermostats for the M54 and have had great results.

I had a wahler thermostat and my temp range was 93-96

I got a Wahler thermostat once who was the OEM maker for MB, the only difference between the Wahler and the old MB one was that there was a spot where the MB logo was, on the Wahler one that logo was gone, looks like it was there, but someone with an angle grinder scratched out the MB logo so it probably came off the same line that made the MB part.

I have had a car not bleed properly/ run hot (but not overheat) only when using the wrong thermostat. Replacing it with Wahler fixed the issue.

I spent a good chunk of change on the Mishimoto thermostat and it got stuck closed within a couple months. Needed the car back right away and all I could get was a dirt cheap MotorRad one. Darn thing has been it in now without issue for a good long while now.

I recently changed the thermostat on my dad's car as well, I went with a wahler, and I'm observing the same things.

I decided to try another thermostat, this time a Wahler and nothing has changed as the car will still not get up to temperature and no hot air.

I changed on mine 2-3 months ago with a new one from Wahler/Borg Warner and now it's leaking through the connector.

I have experienced same with Wahler thermostat.

I’ve replaced it twice and it starts leaking from there in about 2000 miles or so. I’m willing to bet that thermostat is a Wahler brand. They are known to leak like this.