Additional Thermostat? Do I need it?
 

I am trying to determine whether or not the additional thermostat on my 89 325is can be removed and replaced with conventional hoses leading to the heater core.

What does the additional thermostat do or prevent from doing?

Any info would be greatly appreciated.

Thanks,

JohnW8

The thermostat on the heater core is likely to shut of flow to the core if the engine starts to overheat. This is to prevent damage to the core and the interior of the car.

Hmm, I think it may be the other way around, to recirculate hot coolant back into the engine when the car is warming up. You don't want it flowing to the heater core, as that would effectively just cool the coolant, and slow the warm up cycle. I think if you live in a warm environment like SoCal, it wouldn't make much of a difference. But in cold climates, it would probably slow the warm up of the engine...

-Wayne