LS1951

Hey guys. Just picked up a 1988 Callaway Twin Turbo. The car runs and drives great but coming from the Porsche world, the coolant temps shocked me at first! After some research I now know that these cars can run in the upper 230's on a hot day. My question is, what's normal after the engine is shut off? First thing I noticed was that all the fans turned off when I turned the ignition off. There's no way this is normal right?? Temps jumped up to 265 so I turned the key back on and let the fans run for a while. 265 cannot be ok right??

bjankuski

The fans turn off when the key is turned off, that is normal. The other issue of the temp climbing when the engine is off is normal. It is called heat soak and since the water pump is off when the engine is off running the fans will not cool the engine and only wear down the battery so turning the fans off at key off is normal.

cv67

It if were me Id upgrade the cooling system to a better radiator/fan setup, use a 160 stat and lower temp fan switch so it never gets that warm in the first place.

bjankuski

I agree, with that!

TerryOlson

I don't have a twin turbo, but I installed a 180 thermostat and a lower temp fan switch from Corvette Central (on at 190, off at 175 I think). I'm not seeing any more than the low 200s on a 90 degree day idling in traffic with the AC on. The stock fan switch on mine is set to cycle the fan at 238 degrees - way too warm for my liking because it means temps in the 240s. My original interest in lowering engine temp was to resolve a hot-restart issue that I was having. That's a thing of the past as well.

In other threads I've read that the fan switch can be reprogrammed in the ECM of later cars but I don't know what year this became an option.

Cruisinfanatic

That will cool of radiator coolant, not the engine's. You simply need to remove the radiator and clean out the fins properly. That will cool things off a lot

LS1951

ex-x-fire

Does it get to 230 going down the road? It shouldn't.

LS1951

Cruisinfanatic

Like I said. Chances are your radiator is plugged up. Just needs to be cleaned. Lowering the thermostat will not change anything. Putting a lower temp switch is a band aid.

kenmohr

tHERMOSTATS DO NOT LOWER TEMPS. tHEY ARE DESIGNED TO GET ENGINE WARMER SOONER.

bjankuski

yes and no, they will warm an engine up faster and keep it cooler as long as the rest of the cooling system can do its job correctly. As stated by the OP he said lower the t-stat and turn the fans on sooner. As long as the system can keep up the car will run cooler.

BillDurant

https://www.rockauto.com/en/catalog/...,radiator,2172
are these appropriate for the 89 6 speed ?
Or this one ??

FASTAZU

I agree make sure the radiator is clean, turning the fans on sooner is the best way I have the stock 195 thermostat but have my fans set to both on at 210 off at 205 never see temps over 210. 200 while moving. I also always open the hood after a drive just to help let the heat out.

Cruisinfanatic

His problem is not the thermostat and changing it to a lower one won't fix it. The car runs hot

bjankuski

Exactly, Make sure the system is operating as it should so it can extract as much heat out of the system as possible so he can keep the water temperature down to 200 degrees or less. That means make sure it is clean and then program the fans to come on at 200 degrees and off at 195. This is a turbo car, keep it cool if you can.

kenmohr

Thermostats do not control high temps. If that was a true theory just pull the thermos out. There is another explanation for over heating.

bjankuski

If the cooling system has the capacity to remove more heat from the car then it generates then the thermostat does control the high temperature of the system. In this case it is not doing that because either the system is not running as it should be and needs to be fixed, it might be dirty. Also the stock fan settings are 228 and 238 so it will not run cooler then that in town or wherever the airflow is low. The OP wants the car to run cooler so the suggestion is to clean the radiator, turn the cooling fans on earlier and run a lower temp thermostat. See where it runs after that and make changes as necessary. I would suggest a 180 thermostat and 195 on and 190 off fan settings. After those changes if the car will not run at 180 on the highway and 195 in town the radiator would have to be changed to get the car down to the thermostat setting. This is a turbo car, keep it cool.

fake

Take it to ct and have Callaway go threw it before you blow the motor! If you are not a mechanic and you have a no1 car why take the chance.?

Cruisinfanatic

All cars do. Thermostat has ZERO input on how hot it runs. If the car is running hot because of plugged radiator, the lowest temp thermostat put in the car won't change that