Help! Cooling Problem

[83 turbo]

I have an 83 Turbo with an HC turbo engine fitted. I may have a problem with the engine running too cool???? If I let the car warm whilst parked up, the temp gauge rises to just over 90 deg centigrade then the fans kick in. Take it for a run and the temp gauge falls and stops and hovers at the 75 deg cent marker. I have only noticed this over the winter months when the ambient temp has been around 5 deg cent. I thought the previous owner had maybe removed the thermostat or perhaps it was sticking open. Today I replaced it with a new one but the problem still exists. The handbok says optimum running temp is 90, I am concerned that It could damage the engine running 15 degs below the required temp. Anyone got any ideas, and what temp does yours run at on the highway?
Thanx in advance, Jez U.K.

[cnh1990]

In really cold temps below 0 mine runs 82. In warm temps above 100F it runs a little over 90. You can try a hotter opening thermostat. Maybe your gauge is off or the temp sender is malfunctioning which is not unheard of. Sometimes the contacts have corrosion or the sender itself is crusted over with material. Measure the actual coolant temp with a thermometer and compare with the in dash temp gauge before you do anything else.
Calvin 90 SE

[lotusguy]

I have an 83 Turbo with an HC turbo engine fitted. I may have a problem with the engine running too cool???? If I let the car warm whilst parked up, the temp gauge rises to just over 90 deg centigrade then the fans kick in. Take it for a run and the temp gauge falls and stops and hovers at the 75 deg cent marker. I have only noticed this over the winter months when the ambient temp has been around 5 deg cent. I thought the previous owner had maybe removed the thermostat or perhaps it was sticking open. Today I replaced it with a new one but the problem still exists. The handbok says optimum running temp is 90, I am concerned that It could damage the engine running 15 degs below the required temp. Anyone got any ideas, and what temp does yours run at on the highway?
Thanx in advance, Jez U.K.

Jez,

What you describe is not a problem at all. Esprit engines actually run pretty cool so long as they are in motion, this is especially true in the temperate weather common this time of year.

Usually only when you stop does the engine heat really build up. Of course, in normal city driving in summer climes, there is usually insufficient time between stops to dissapate all the heat build-up. One possibility though is that you have an obstruction in a coolant line. The best way to check this is to open the bleed valve on the radiator (located on the left hand side by opening the boot and removing the little cover in the front boot floor, then open the expansion tank and pressurise it or cup your hand over the opening and blow into it taking care not to ingest any ethylene glycol. You should see coolant flowing out the bleed valve.

I'm pretty sure everything is ok, but you won't be able to really check it fully 'til the ambient temps stay at about 70°F. Happy Motoring!...Jim'85TE