I just picked up my 96 LT1 about three weeks ago. It seems that while driving my in stop and go traffic the temp. gauge runs way up to about 240degrees. I've heard that this is not altogether abnormal for these cars. I'm considering just popping in a 160 deg. thermostat. Would this be as simple an answer to the problem as it seems, or should I expect any performance complications from this. :confused:

 

you can throw a 160 in there, they shouldve come from the factory with lower tstats

however, in traffic it may not help the problem, as the fans need to be set to come on earlier, this will require a hypertech Power programmer

 

I think the LT1 has a 160deg stat. You can verify this by checking the coolant temp during highway driving.

You'll need to get the ECM reprogrammed to lower the fan On temps.

 

Keep in mind that thermostats only controll minimum temperature, once there open, there open. As stated previously programing to turn the fans on sooner is the ticket. What worked for me was turning on at 200 degrees and off at 190 degrees with a 160 degree stat. The car never saw over 200 degrees in heavy traffic and never over 180 degrees to 185 degrees at highway speeds in the summer. Now the winter was another story, it never reaches over 165 degrees with ambient temperture below 30 degrees. Hope this helps.

 

The thermostat alone does not control the coolant temperature. If you see 240 in slow traffic, then your 185 thermostat is wide open and a 160 thermostat will also be wide open and you will still see 240 F. The radiator in C4's are sized intended for 185 F (factory stat) operation. At low speeds the fan will be turned on at 228 F and the auxialliary fan comes on at 238 F. Use of a 160 stat and turning on the fans at a lower temp simply will not maintain your coolant at 160 because the radiator cannot get rid of heat fast enough. Also, a 160 stat will operate the engine at 160 when you are well above about 35 mph because enough air will pass through the radiator to get rid of heat fast enough to allow the 160 stat to control the engine temp. 160 is too low for high speed operation. Another contributor to the soaring temps at low speed is the GM waterpump which has inadequite flow at idle speed. I recently replaced my waterpump with a Stewart pump which has 41 % more flow at idle and when I see my temp soar, I turn on my fan with an add-on fan switch and the temp comes back down. Also, debris collects in the radiator and decreases air flow. Removing the radiator shroud will allow access to the radiator and it can be cleaned. I had better cooling when I blasted water with a garden hose backwards through my radiator and then flushed out the debris by blasting water around the radiator cap gap. I didn't want to go through the shroud removal. Look into the air scoop and see if the a/c condenser has any fins bent or has debris stuck in it and clean/straighten which will increase air flow.
Installing a 160 stat and turning on the fan at a lower temp for red lights will do nothing for where the engine temp stabilizes, it will stabilize at the same temperature as a 185 stat does because BOTH a 160 and 185 stat will be wide open and no longer have any control over coolant temperature.

 

The factory stats are 180. I bet that if you pull your radiator and clean the fins it will make a big difference. Also try this, around 228 degrees make sure the fans are running, if not then turn on the ac and see if they start then. If they do and it still stays hot (240) then pull the radiator and clean it.