Okay people, I have a 88 camaro with a 83 305/ 700r4(original). It has a edelbrock cam, pushrods and lifters. Edelbrock intake and carb. The heads have been ported and polished to match the rest of the setup and the usual stuff(water pump, radiator, thermostat180, electric fan 2950cfm) have also been replaced. Oh ya and headers too.
The car warms up to about 185-190 when I first start driving. When I go up any hills the car begins to heat-up to about 220-230. If I get on the pedal(not on hill) the car heats-up just the same. But when I idle the car will begin to cool back down. Because of this I've had to keep the car under 65 and I can't go on long trips. The problem with that is that I commute 70 miles to school, one way.
Guys please help me. I can't figure this out but I'm confident it isn't much. This engine is the first engine I've ever built-up and I've done it on my own. I've had to ask many questions on the way but I got it going. This problem however is the only thing holding it back. Thanks... the timing is at 14 degrees which is what the cam card said to put it at,14-16. If I go below this it will bog, but I can go up with no pinging.

 

WHat distributor? If you are still using the stock computer controlled HEI they you need to yank that and put in a non-computer controlled HEI cause the computer (what's left of it) is now running in "limp home" mode due to it not seeing the original computer controlled carb hooked up. Result- really weak advance curve, possibly making the overheating worse.

Putting that aside for right now let's look at some simple stuff:

1. The old "chin spoiler." Its a 4" black plastic piece that bolts on under the radiator support. If it's not there your highway cooling will suffere even if you have the electric fans rigged to run all the time.

2. Are the belts tight?

3. The lower rad. hose should have an "anti-collapse" spring inside it so the water pump can't suck it flat when the revs come up. Give it a squeeze by hand (engine cold) and you should NOT be able to squeeze it flat- you will feel the spring inside if its there.

4. Coolant should not be MORE THAN 50% anti-freeze. Anti Freeze isn't a very good coolant which is why you mix it at least 50/50 with water.

5. Since you did the pump, stat, etc., there's only two things left- the radiator itself and the rad. cap. They can get pretty messed up after 100K+ miles and it might be worth looking into new ones anyway.

6. Popped head gasket. Hate to bring this up but often a blown/leaky head gasket can blow bubbles into the water jacket area interrupting flow and acting almost like an insulator. A dead giveaway will be bubbles blowing into the radiator/overflow tank while the engine is running.


------------------
94 Firebird Formula M6- No options but Z rated tires. No mods over $10. 13.5@105.
79 Malibu "beater" w/junkyard 400 SBC, tweaked QJet 4bbl, finally a decent set of heads, a few other tricks. A maddening 13.000001 @ 108 on the motor with little traction. No nitrous runs with the new heads yet.
Grandma's old 78 Malibu (33K miles!) soon to have the powertrain from the 79 put in it.

"One of the last remaining QJet tuners on Planet Earth!"

 

Damon, how would I know if the distributor is for a computer controlled engine. That's about the only part that I haven't bought new. I bought it from a recking yard that told me it would work. It does have a vacume advance and has no plug-ins except the wires for the super coil which sits on top of the cap. I junked the old distributor that came with the engine. It however had several wires as well as a computer controlled carb.
I also don't have a fully intact front air-dam. There's only a small piece that's angled but sits about maybe 2 inches down. You can't see it without looking under the car. If this is the problem would it also effect the heating when climbing hills?
The radiator has less than couple thousand miles as well as the cap. Though the fliud is roughly half and half as faras I know?
And for the belts, they're as tight as I can get them. The water pump+belt is new as is the power steering+belt and alternator+belt.
I hope that might narrow things down a bit?

 

JC88Camaro,
It seems that you airdam or as Damon calls it "chin spoiler" under the radiator is bad or missing. Without the piece or having a damaged one it will not let any air get up to the radiator, hence causing the car to over heat. This will be noticed mostly when highway driving leting the temp get to 240* or higher. But when you stop the fan(s) can pull air in and you'll see the temperature drop.
You can get a replacement part at any GM parts dealer for under $30 and you may need new bolts to bolt it up ( 6 or 7 bolts and washers).
I know this problem cause it happen to me!

Good Luck!

 

..... and you're probably OK with that distributor- it's an older NON-computer controlled one so you've got a good start. Just make sure that the centrifugal and advnace mechanisms are not "locked up" from rust/corrosion. Lack of advance WILL cause overheating and so will TOO MUCH advance. THere's an article in the tech section about prepping the non-computer controlled HEI for performance that you should read. You may want to compare your current distibutor's advance curve to what it SHOULD be ideally. If yours is way off it could be making the overheating problem worse. MOST COMMON DISTRIBUTOR MISTAKE: using a stock vacuum advance canister but advancing the base timing well beyond stock and/or without the combustion "cooling" benefit of an EGR valve.

Anyways, that chin spoiler is the NUMBER ONE reason for 3rd gens to run hot. Get a new one and make sure it is held in place with ALL the bolts- not just one or two. It has to stay rigid against a strong stream of air while the car is moving forward.



[This message has been edited by Damon (edited September 29, 2000).]

 

Damon, I just went and ordered a new air deflector from a chevy dealership. I tried to get one from a junk yard but had no luck. Though I'm glad I didn't because it's only 22.50 for a new one. I'm supposed to get it by Tuesday of next week.
After reading your first response I started thinking about getting a new distributor, maybe a MSD or something. What one do you think is good for my setup. Thanks alot, Jason

 

check the air cond.condesor in front of the radiator for blockage...ie feathers,leaves ,paper..and look at the front of the rad too

------------------
87GTA,MAF screens removed,K&N,modified air intake,ADSchip,3:73s,3inch cat back Flowmaster,TPS.54,Bosch Plat plugs,base timing 6BTDC,Bilstiens in the rear....,don't let yer meat loaf

 

That air condensor is one evil SOB. My IROC used to overheat all the time. I had my a/c system evacuated and yanked the condensor to clean it out. Not only was it completely clogged with 12 years or crap and crud, but all the fins were flattened to prevent any air from flowing through, I drove for a week w/o the condensor, while I straightened all the fins back and cleaned out all that crap stuck in it. Result - cooling system works like the condensor isn't even there.

------------------
'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler

 

Thanks guys, but the condenser is out already as is the whole air condition system. I've deleted everything I could delete including all smog equipment and don't worry, I don't have to have the car smogged like everyone else. Here in Valley Springs your only required to smog the car when you first buy it and when you sell it. No other time Jason

 

Thanks guys, but the condenser is out already as is the whole air condition system. I've deleted everything I could delete including all smog equipment and don't worry, I don't have to have the car smogged like everyone else. Here in Valley Springs your only required to smog the car when you first buy it and when you sell it. No other time Jason

 

I wish to add one thing here, the "chin spoiler" will only make a difference if you have all the ducting in place inside the front nose peice. They are the upper and lower radiator baffles and they channel the air straight to the radiator instead of underneath it or around it. This is because the air will travel the path of least resistance, so it wiil try to go around the radiator unless it is directed with the baffling. ALso the chin spoiler creates a low pressure area behind the radiator to help draw more air through it. It is obvious that the above mentioned prob. is due to misdirected air because it worsens at higher or sustained speed, rather than when sitting still. One other thing, the fans are nearly as effective when the vehicle is moving as when it is still, this is why the airflow baffles are so criticle.

------------------
"84Z28/'91 305TPI comp cam flowmaster TB coolant bypass/shutoff valve to heater core MAT relocated Ram-Air(home-made) gutted air-box IROC ground effects/wheels GY245/50's 700R4 superior shift kit/ corvette servo(excellent shift kit BTW) Rebuilt engine and transplanted it myself. Love this engine!
LOW performance people should drive low performance vehicles!