Thermostat Gates or Wahler

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 only use Gates now after some cheap ones failed but didn't leak. Gates are very good. I have not had to replace one.

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.

My 2007 MKV 2.5 Jetta is still having overheat problems even after changing the tstat to a OEM (Wahler) and the waterpump to one with metal impeller, which works way better than the original.

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 installed a Gates one a couple months back and it worked well for a little while; engine got up to operating temp fairly quickly and stayed there, but now it’s running really cold no matter how long or how hard I drive it. Think it’s stuck open.

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