ian9123

Hi there, posting here because I'm not sure what my next step should be. Recently acquired an 89 camaro rs 2.8L v6 5-speed.
Got it back about a month ago from mechanic, had to have the wiring completely re-done (prev owner let friend try to install undercarriage lights, ended up un-hooking rad fan to install lights, ghetto rig to the max). Drove it back from mechanic, highway speeds, car ran real hot, could hear water boiling over into overflow tank.

After letting it cool i popped off rad cap, noticed it needed a flush. Coolant was pretty much murky brown-ish water. Flushed rad completely, filled with 50/50. Let car idle for ~20 mins with cap off to bleed radiator, seemed to have good flow. Fan seemed to work fine, came on around 220, after coming on it cooled the engine back down to a good temp.

After flushing, the car no longer runs hot at highway speeds. I live in hot and humid south florida, and on highway it runs about 200-220, very steadily. Now the problem is when i go to park at work after a decent drive in the hot weather, or when i drive stop and start in my area. The other day i drove around the lot a few times trying to find a good spot and when i parked i noticed my car VERY close to the red and i could hear the overflow tank boiling. this also happens if traffic is slow.
So when it gets hot like this i let it cool off and after about 20 minutes i can start it again and the fan seems to kick in and cool it back down to about 220, and when i get back to highway speeds it cools back to its "normal" running temperature.

Im not sure exactly what the problem is, i'm leaning toward the fans due to shoddy wiring from original owner. mechanic verified it was working in his possession, but im just not sure it kicks in 100% of the time due to low speed overheating.

any help is appreciated!

90 camaro cj

did you check the flow through the radiator? on my 90 TBI it was getting hotter then i liked with the A/C on, i put in a new radiator because the one in the car was from the mid 90s mine too had murky brown coolant. the radiator i got was a Venguard, has a lifetime warranty and was 85 bucks i installed it myself. now it doesnt get nearly as warm with the A/c on stays right at the mark between 100 and 220. just a thought

ian9123

yeah when i flushed and bled the rad i noticed it had good flow, all the hoses are in good shape, doesnt appear to have any kind of blockages.

just double checked coolant levels, topped it off a bit, and took it for a drive. ran really cool on the open road (55 mph), right around 170. I pulled up to my driveway, already noticing the temp climbing. so i got out, popped hood and let it idle while watching for the fan to come on. Lo and behold it never came on, let temp get to 250 before shutting her off.

90 camaro cj

fix that nasty solder job if its still there and check the plug on the fan see if its burnt or anything?

Scorpner

iTrader: (4)

Also check that the fins for both the radiator and A/C evaporator aren't clogged with debris. It's commonly overlooked and could contribute to it overheating.

JamesC

iTrader: (5)

Is the air dam in place?

JamesC

ian9123

Well...half of it is. Its still rigid and attached solidly...but apparently half of it broke off at some point.

Will take a look at all the wires for the fan tomorrow during daylight, friend at work mentioned it sounds like a problem with the fan relay.

JamesC

iTrader: (5)

Replace the air dam.

https://www.thirdgen.org/forums/cool...-dam-test.html

JamesC