I just purchased and installed a new pump on my 84 berlinetta tonight with the 2.8.

They pump was leaking from the bottom weep hole. Anyhow, I get it buttoned up and filled with fresh coolant. I start it and it runs for about 5 minutes and is at 220* on the cluster. I am guessing it is the thermostat, what do you guys think?

 

IDK if this applies to 3rd gen, but my '91 Blazer would show over 220* just turning the key and would have a hard time starting. Turned out to be some kind of temp sensor was bad.

Our Camaro doesn't have any ECM so IDK if there's one in 3rd gens or not.
5 mins driving or idling? Hoses feel hot?

 

lower hose feels warm and the top hose that goes to the thermostat stays cool. Also after it gets to that temp there is a ton of pressure on the system, but no steam.

If I let it run, it will peg the gauge at 260*.

I have not driven the car yet, I am afraid to. I do not know how fragile these things are to overheating

 

air in the system? thermostat is easy to change too. Siphon down radiator level until it's just below thermostat. Pull it off and see if there's coolant right there. Fill coolant up to top of hole, put new thermostat in, add a bit to radiator until it starts coming out around thermostat. Push down on plunger a little bit to get air out, put t-stat housing and hose back on, and fill radiator back up.

That's how I usually do it (a little pushing up and down on the upper hose too to work the air out of it), and I hardly have to add any once it warms up.

With a new pump and t-stat and all the air out of the system, if it still over-heats while idling, the fan isn't coming on (electric right?), there's a passage blocked, or the radiator core is plugged.

I can't think of anymore than that at the moment.

 

Fan(s) turn on?
Do you have a new thermostsat already, but not installed? I don't think it would hurt to put it in.

Gurus will have to chime in on this. IDK how to test the fan circuits // relays.

 

It was a clutch manual fan car, but I have added an e-fan with a switch in the head and an over ride switch. No, the fan didnt come on though

I am going to put a thermostat in it tomorrow and bring my IR temp gun tomorrow and check the temp that way.

 

I see my EDIT didn't go...
coolrimsatleast makes a good point-- air pocket can cause a problem.

IR gun would be an idea!

 

If that engine has a coolant temperature sensor (or some sensor or switch in the intake coolant passages), remove it and put coolant directly into the engine. Then fill the radiator and overflow bottle again. You have a MASSIVE air pocket right underneath the thermostat, which is why the sender reads hot after only 5 minutes. That's why I fill the engine first and then the radiator.

 

After I had heard about the history of the car(over heated quite a few times), I went ahead and replaced the thermostat. While I had it out, I filled the block that way. Oddly enough it took about half a gallon.

We drove it around tonight a little bit, put fresh gas and aired the tires up.

Thanks everyone.

 

if it's still running hot and when you accelerate it pings, check your timing...

 

Its all good right now, I am going to run it around in some day time heat and make sure.

It idled in the driveway for about 45 minutes with the fan cycling on and off. It didnt get to about 190 degrees via the ir gun.