millsj

I recently replaced the waterpump on my 86' 951. I decided to install a lower temp rated main thermostat. (71C if I recall) I also replaced the turbo thermostat on the front of the water pump with a new factory stat. Problem is this: after turning off the car the aux. water pump now runs for several (5+) minutes before cycling off and on for approx. 25 secs. Prior to the water pump/stat changes the pump would run for 25 sec.s and then cycle off and on a couple of more times before shutting down for good. If I unplug the temp sensor the pump will shut off after 25 secs indicating to me that the sensor is hot and calling for cooling. Now that the engine/coolant is running much cooler (below the 1st white line)due to the lower tempo stat.; is it possible that it is no longer hot enough to open the turbo thermostat and cycle water thru the turbo? Can I remove the turbo thermostat and run without it? If so, what are the concerns? Thanks.... Joe

Danno

I was wondering about that too. Appears there must be some sort of one-way flow control with the two thermostats.

Although I don't see why people install lower-temp thermostats in their car anyway. It will just take your car longer to warm up. If you have an overheating problem, a thermostat won't help. Once your car gets to 71C or 83C, both thermostats are fully open anyway; flowing the same amount of water. And if you don't have an overheating problem, running your car at a lower temperature than its design spec will have you making less power. That's because more heat energy from the combustion chambers will go into the cooler cylinder walls instead of out the tailpipe to power the turbo.

Anyway, Joe, your turbo is beating away and living well in my car!

Jerry

There is a ideal temp range the whole motor was designed to operate at and you want to be in that range. I f you have cleaned your motor recently sometimes that will make strange things happen.

cruise98

I removed my turbo thermostat at the water pump. I have noticed no ill effects.