Thermostat Mahle or Wahler

I’ve installed Borg Wagner thermostats and those always failed until I installed a Mahle one which never failed. For some reason any other brand will get stuck open and the engine will never get up to temp.

I used Mahle, but I got lucky I got the German-made one (afaik now most are made in Italy). It was NOS so I expect the electrical heater (to open early) to be defect. It's been 3 years without issue though.

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 brand new mahle one with the connector wired in reverse for constant. Kept blowing a fuse. Returned it for a replacement and worked fine.

Mahle is an OEM supplier and is on stock in Amazon.

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

Hatte auch schon ein Mahle Thermostat das kurz nach eimbau defekt war. Dannach ein Originales von BMW rein und seit dem wi3der keine Probleme.

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.