I put in a 160 thermo yesterday in hopes of curing my problem of my car running a little hot. Well what happens is my car will warm up to 160 in about 5 min of driving, it will stay at 160 for about 30seconds maybe a little more and then continue to climb whether i am sitting still or driving. it will then go all the way to 200 which is when my fan kicks in and stay there, it will not go down unless you are driving for like 20 min and then maybe it might drop to 195. My fan is working and my air dam is in place, i dont know what to do. What should i check , what could be causing this? All help is greatly appreciated.

 

it could be a clog somewhere in the system, maybe around the heater core, what kinda condition are the hoses in?

what kinda flow ss the water pump giving?
when the last time u replaced the radiator cap?

with a 160 stat u shouldnt get that high on the highway.

what year, model, etc.. is ur thirdgen?

 

The radiator cap was replaced about a year ago, maybe i should change that, but that would be too easy lol. the water pump and the radiator are only a few months old. It is an 88 camaro sc with a gm 350 with less than 1600 miles on it and i havent been on the highway yet but i have been crusing at about 45-50. The hoses appear to be in pretty good shape, i replaced most of them when i did the motor swap.

 

FWIW i have had new thermostats stay closed.........

 

I went home yesterday and popped the hood and some coolant was leaking from the thermostat housing gasket, i pulled it off and put a new gasket on, i rechecked the air dam, checked th air thing behind the grill that leads air into the radiator. There is no debris on the condensor or on the radiator and i tried a different cap same results. last night when cruising in 65 degree weather the car got up to 208 with the heat on and the fan going full blast and this is basically cruising at about 45-50mph. I pulled over and loosened the rad cap and a litlle air came out but it did nothing as far as the car running cooler. Even though the condensor looked ok is it possible it is not and somehow blocking my airflow, what else could it be? help!

 

CAMAROsc350
You say you put in a GM350 motor, are you still running the all the computer hookups and emssions on the car? If so, what is your timing set at? If the timing is retarded it will run hot and also if you are running the computer yet you would need to have a new prom chip for the computer. It will reprogram the running parimeters for a 160 therm. change the timing, fuel curve, etc. which would also turn on the elec. fan sooner. If you are still running the stock prom in the computer then the computer does alot of strange things without necessarily throwing a code.
If you are not running the computer and related emissions comp. then again check the timing both initial and total and then reset the carb. My car was running a little warm but when it came to getting the timing and carb set up right, I finally took it to a professional who got it perfect. Now it's staying cool, I think I'm actually going to put the ac back in next year. Also, one other thing I did that helped tremendously was the installation of an aftermarket aluminum radiator.
Hope you can get it cooled down, I know that it is very frustrating in deed.
Chet cc82z-28

 

cc 82Z-28: The car is no longer computer controlled and im pretty sure the timing is right however i will check it because it is definately a possibility since it has moved once before. This is very frustrating and i hope i get it figured out soon too. Are there any more possibilities or are you pretty set on it being the timing. Thanks

 

camarosc350
If you determine that timing is ok, then check your spark plugs to see what they look like. Make sure you're not running lean on the mixture as that will contribute to running hot. Are you running a quadrajet or a holley carb? What are you runninf for fuel pressure? I put an in line fuel pressure gauge on my car to make sure I had enough pressure but not too much.
As for your water pump, is it a stock unit or a high performance unit? I put plate on the back of the impellar of my water pump to increase its volume which in turn moves more water without the cavitation effects. Make sure the belts are not slipping, if they are it will not spin the water pump as it should, also make sure you have a water pump that spins in the right direction for your motor. A friend of mine had an overheating problem and turns out he had reverse rotation pump on his motor, he got the right pump, problem solved. As for blockage in the heater core, try not using the heater core in the loop by disconnecting it and using bypass hoses and cap it off to see if the problem goes away, if not reconnect it back.
These are a few more suggestions, hope one of them work for you.
Chet cc82z-28

 

cc 82Z-28: my friend is hopefully coming over later with his timing gun and were going to check that first, cars definately not lean 7mpg lol. I am running an edel 600, my fp is good, the water pump is a stock replacement and im pretty sure its the right one, it would probably be running a bit hotter than it is now if it was wrong. The belts are not slipping, hopefully the timing is just a little off but if not i will definately start narrowing the list. Ill keep you updated and thanks for the help.

 

CAMAROsc350
One more thing as for the water pump, are you still running the serpentine belt system? If that's what your car had on it from the factory then I think the water pump runs in reverse of what older v-belt system such as mine run. That friend of mine I told you about did just that, he put the motor in his truck with his v-belt system and the motor originally had a serpentine belt system on it. It is easy to overlook that one believe me. As I said yesterday as soon as he was told to check the pump direction he realized that he had the wrong pump on for v-belt configuration.
If the motor you got was set up for v-belt and you run a serpentine belt the same problem would arise.
Good luck and I hope you're successful in finding your problem so you can start enjoying your car. I know, I'm now being able to start having fun with my car.
Chet cc82z-28

 

Update : still need help
During the week i have checked the timing checked the plugs to make sure i wasnt running lean changed the thermo back to a 180 and drilled two holes in it, same results even when having the heat on when driving does practically nothing which is pretty weird, could this be part of the problem? Another thing that i am finding odd is even after i changed the thermo again the gasket leaks, this is the 3rd gasket ive put in the last 2 weeks and i know for a fact that i put it on right, it didnt leak at first it took a few hours before doing so and then it just seeps out very lightly. I am going crazy i was driving around last night with the car at 210 with the heat on full blast as well as the fan. Should i flush the system even though the coolant is only a few months old? And also one more question(sorry) when you turn the lever to cold on the heater controls dosent that block off the flow off coolant through the heater core or no? I am trying to elimanate all possibilties one at a time. all help is greatly appreciated. Thanks

 

Anyone? all ideas are helpful and all help is appreciated.