Reviews of GRAF thermostat

I had the same problem when I put in the all aluminum graf waterpump. It had a bad thermostat right from the factory, I replaced the thermostat after trying all sorts of coolant bleeding, temp logging, etc. The oem thermostat solved the problem.

I had the same problem after installing the metal graf water pump. The problem is caused by the cheap thermostat that comes with the kit( assuming it is the graf kit). I put a stock OEM thermostat back on, and now the temps are fine.

Thermostat for Graf Aluminum Water Pump I have rebuilt my 09 Eos with this pump. It worked properly for the first week, then the thermostat started sticking partly open, resulting is slow warm up, but proper temperature after several miles.