Why is my camaro is overheating?

Question

I have a auto. 1990 Chevy Camaro, I swapped the 305 for a carbureted 350, and everytime I drive it for more than about 15 min. it starts to overheat. It usually overheats the most when I'm in stop and go traffic but it also overheats when there is no traffic... it just takes longer. The water pump is good, I flushed the radiator, and I have a 160thermastat in it. But I am almost positive that the timing is off slightly because when we put the new engine in I didn't have a timing light, I know that the chevy 350 should be timed at 4 degrees before tdc but the guy that put my engine in also put in a "mild cam", and I don't know exactly what timing it should be at with a mild cam so I just timed it the best I could by ear, also at least one of the spark plug wires has a bad connection. Could this be causing it to overheat? What should the timing be for a chevy 350 with a mild cam? thanks

Answer 1

I own a shop, and have seen this one before. You probably have the wrong water pump on it. One is a reverse flow, and the other is not, so when put in with the water pump running backwards, it won't pump enough to keep the engine cool. Many things can cause it to overheat. Start by pumping up the system with a pressure tester, and don't forget to check the cap. Did you bypass the computer? This does matter as to the answer. A mild cam and a 305 computer won't work! The timing must be set at whatever it works out to be. If you don't know how to figure your total timing, then go to this site
www.chevyhiperformance.com
and look for a past article on setting up your ignition timing. Your timing could be from 4 degrees on up to 12-14 degrees of intital timing, but you must consider mechanical, and vacuum advance timing into the equation to come up with your base timing, if you don't know the base timing. An engine that is low on igniton timing runs hotter. Kick it up a few degrees to see if it fixes the problem. If one overheats when it's sitting still, it could be the wrong or bad water pump, radiator stopped up, wrong thermostat, a fan issue with it not running enough due to the wrong thermostat in it. A stuck thermostat, or a radiator hose collapsing. A cracked head or bad head gasket can do this too. I have seen the coolant not staying in the radiator long enough for it to cool down, cause this. As for your timing, run it up until it starts to kick back, and back it down until it will start good, and you should be close enough until you can do it better. Remember; the lower the timing, the hotter the engine.
Glad to help out, Good luck!!!

Answer 2

Be sure the electric fan is working, this sounds like a car with no computer, if so I would go with aftermarket thermal switches to control the fan, one that will turn it on and also keep it running after engine shutdown to bring it down to about 130 before turning the fan off. Also replace the radiator cap, it may not be allowing the cooling system to pressurize, I've had that happen about a dozen times. As someone else already said check your thermostat, just because its new doesn't always mean it's good, put it in a pot of water and heat it up with a thermometer in the water and watch to see if it opens around its rated temp. And again make sure air can get to the radiator which could also be a problem. For starters have a shop pressure check your entire cooling system, sometimes just the check will expose problems.

Answer 3

timing would have little do with it unless it;s retarded to the point not allowing the engine to fully combust the mixture, causing hot cylinder walls = hot engine. Make sure your electric? fan is turning on when appropriate, see if the thermostat is opening. Just because it;s new doesn't mean it can't malfunction. See if the upper radiator hose is hot, warm. The reason it overheats in traffic is due to decreased air flow that isn't assisting in cooling off the engine.

Answer 4

Nick, underneath the car is a piece of plastic called an "air dam" located under the radiator support that forces air up into the radiator. Is it there? What it does is force air up into the radiator from underneath. With the design of your car and many more grille openings are for show and not practicality. Your car is equipped with an electric fan, is that working? Also since ya went with a carb if its set too lean that will cause an overheating problem as well . So richen up the mixture screws a littl(e if the air dam is in place) and that will take care of your overheating problem

Answer 5

Im sorry to assert yet i think of you get carry of two undesirable theromostats. this is why. the perfect hose could be warm and be particularly frustrating to squeeze. try this a million extra time. do away with the theromistat and placed a pot of water on the range. Boil the water and then drop the theromostate in and notice if it opens. If it does that's possable the water pump isn't working and imparting the water it needs.

Answer 6

More displacement bigger radatior please! and 4 degrees is kind of slow timing. Get a bigger radatior and set the timing at about 12 to 20 degrees and rev up to 3,000 and attain about 35 to 45 total advance on a 4bbl 350 anf you will have even more Hp. Use good gasoline too

Answer 7

Check your fan clutch, usually when you are in traffic that is the problem.

Answer 8

you might need to replace the air intake or get more coolent