Anybody that has recently responded to my thread about overheating with a/c on can put that on the backburner for now because now the damn car is overheating without the air on. As some of you might know from my previous threads, i had my timing chain slip off my gears because of worn and broken teeth. I put a new oil pump, water pump, pushrods and timing gears and chain. Yesterday i completely put the engine together and with extreme difficulty finally got the timing close enough for the engine to idle and rev cleanly. After running for no more than 5 minutes the temperature went up to 230 than about 10 minutes later 250. I adjusted the valves by the book with the engine off, one cylinder at a time. I took the thermostat out but that didn't help. It didn't do this before the timing chain went. I'm getting so fed up with this crap
85 vette
assuming the thermostat was stuck closed, the increase in capacity of coolant should reduce engine temps even if the rad didn't work at all.frankenstang57 said:What kinda car and motor? Are you sure the timing marks are lined up? Taking the thermostat out will actually cause the car to run hotter. The coolant passes too quickly through the motor to dissipate the heat.
Also i would think that statement would be cause of some debate, it is not necisarily true that running without a t-stat will make the motor run hotter. I can see the argument of both sides. It would depend on the capacity of the rad, the motor, the efficiency of the rad, the flow of the pump, the flow of the thermostat ect ect.
Check your timing. A retarded timing will cause you to overheat very quickly at idle (ten minutes or less). You will more than likely also see the exhaust pipes just below the exhaust manifolds glowing cherry red. This is a definate sign of a retarded ignition timing.
Also check for vacuum leaks. This will cause a lean condition and can also cause overheating.
Use a good 180 degree thermostat! Do not run it without a thermostat.
If your water temp sending unit is in the head rather than the intake manifold the temp gauge will read about 20 degrees more than the coolant temp.
Also check for vacuum leaks. This will cause a lean condition and can also cause overheating.
Use a good 180 degree thermostat! Do not run it without a thermostat.
If your water temp sending unit is in the head rather than the intake manifold the temp gauge will read about 20 degrees more than the coolant temp.
Did you reconnect the EST after the initial timing? I just mention it as we JUST put a new cam in an 85 Vette and went through the same thing you are. The headers started to glow red. Shut it down and remembered to plug in the EST once base timing was set.
Then while it was running and I was doing cam breakin (watching the time and coolant temp), my friend, who owns the car, was burping the radiator of air and making sure it was full. This quickly dropped the temps from 230 down to 195 or so.
Make sure you aren't getting any vacuum leaks and that the MAF is getting a correct reading. Anything that is adding more air physically to the engine, or making the engine THINK its getting less air, is going to lean out the system causing a hotter engine.
Perhaps check the plugs and see what they look like.
Then while it was running and I was doing cam breakin (watching the time and coolant temp), my friend, who owns the car, was burping the radiator of air and making sure it was full. This quickly dropped the temps from 230 down to 195 or so.
Make sure you aren't getting any vacuum leaks and that the MAF is getting a correct reading. Anything that is adding more air physically to the engine, or making the engine THINK its getting less air, is going to lean out the system causing a hotter engine.
Perhaps check the plugs and see what they look like.
Hot topic
Did you use a degree wheel and dial indicator to check your cam timing as well?
Due to manufacturing tolarances, its entirely possible your cam is retarded way too much. If thats the case, then your engine will run hot as its like running in a super lean condition all the time.
That was a problem with a lot of cars built during the mid and late 70's, as the factories did retard cams a lot in order to meet immission standards. Consequently, a lot of cars ran way too hot from the factory.
Did you use a degree wheel and dial indicator to check your cam timing as well?
Due to manufacturing tolarances, its entirely possible your cam is retarded way too much. If thats the case, then your engine will run hot as its like running in a super lean condition all the time.
That was a problem with a lot of cars built during the mid and late 70's, as the factories did retard cams a lot in order to meet immission standards. Consequently, a lot of cars ran way too hot from the factory.
85 vette
the answer is one or both listed in the previous posts,
to much air or not enough timing.....way lean burn
one more maybe, did you hook up the vacuum advance, computers want everything working or they puck.....
put the thermostat back in,
it wasn't overheating before you tore it down,
don't make it more complicated with a 3rd variable
the answer is one or both listed in the previous posts,
to much air or not enough timing.....way lean burn
one more maybe, did you hook up the vacuum advance, computers want everything working or they puck.....
put the thermostat back in,
it wasn't overheating before you tore it down,
don't make it more complicated with a 3rd variable
The 85 Vette had no vacuum advance. Other than base timing (which was set by the user) the entire timing system is ran by the ESC (Electronic Spark Controller).
Anyways . . . I think the problem lies in one of the areas that was mentioned above.
Anyways . . . I think the problem lies in one of the areas that was mentioned above.
FOUND IT!!! Damn. This car drove me crazy. I must have pulled the distributor 7 times checking and rechecking timing . Trying it here and there but the car would still run like crap. The only time it would resemble running was when i would advance the distributor so much i could hear a snap in my left nut. That and the overheating simultaneously were stretching my limits and patience. And then i found it.. a stupid, simple vacuum line under the plenum. I hooked it back up and lo and behold it idled. It didn't get over 170* in 30 minutes. It revved. It was a normal car again. 2 birds with one stone. That thing was running so lean from the leak that the engine overheated and it ran like crapola. I'd like to thank everybody for their insight and suggestions. As usual always good advice. I'd also like to thank the academy and all the little people that got me where i am today. lol rick
Always the little things causing the problems aint it .
Glad to see you got it fixed. Enjoy the drive.
.Glad to see you got it fixed. Enjoy the drive.
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