tact78

What's normal operating temp for a 75 c3 and or best way to deal with high engine temp? Thanks!

resdoggie

Normal temp is the rating of the thermostat. If you have a 195* tstat, then normal temps when thoroughly warmed would be 195*-ish for a properly functioning coolant system. Define high engine temps please.

tact78

230-280

Easy Mike

That range is scary high if you are consistently getting those readings. 190-220 is a common operating range.

tact78

just got it drove 1:45 back home ran about 210 for 40. Minutes then went to 230 . jumped just under red pulled over sat an hour then ran home at 230started fine the next morning been sitting until registered and tagged.

v2racing

You need to check the temp with a infrared heat gun at the engine temp sensor and thermostat housing. These old gauges can be off a ways. If it is running that hot for real, then you have some checking to do. There are several things that can make these C3's run hot. Missing lower spoiler in front, missing radiator and hood seals, retarded ignition timing, gunk buildup in radiator, collapsing lower radiator hose, and so on.

Mike

7T1vette

If you have a stock engine and cooling system setup, you likely need to change the thermostat (still need to put 195F stat in, because of the ECU requirements) and CLEAN [not flush] your radiator out well. You might also have some issue with the thermostatic fan on the water pump. They can go bad, so that they don't lock-in when their prescribed temperature is reached, and that will make you run hot.

There is an easy 'test' to determine if the thermo-fam is working, or not. Ask if you need it.

tact78

How do you test as im new to this? Thanks again

Strokemyaxe

7T1vette

Get car up to operating temps...up where the thermo-fan should turn on (slow speed, A/C on, hot day, whatever you can do to get it sufficiently warm). Stop, leave engine ruinning, open hood, stand just outside the driver's door and while watching the fan, turn the ignition key OFF. If the fan stops rotating in 3 or less rotations, it is engaging like it should. If it just spins down slowly,it is not engaging when it gets hot. When the engine is hot, you should hear the 'wind' noise of the fan when the thermo-unit engages. Depending on your model and engine/trans configuration, that fan should engage in the 200F-220F range.