Thermostat Mahle or OEM Mazda

I replaced my newly bought Wahler t-stat with my old Mahle but drilled. Temps stays 80-87c.

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.

Always buy the Mazda OEM branded thermostat from any local or online Mazda factory parts retailer, this is not the item you want to save a couple bucks on, no matter how much you trust that ‘other’ brand.

Make sure you use a Mazda OEM thermostat. I wouldn’t trust anything but OEM for those.

Swapped to mahle and it's good to go.

They kept it for another day and were obviously able to replicate the fault and replaced the Thermostat as they thought it was sticking causing the Temps to fluctuate.

The Mahle thermostat arrived today along with all the other bits I think I need to put the car back together. The problem is that the new one doesn't quite match the old one.

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.