Ceedub53

mmartinez

Glad to hear that things are looking better, you mentioned that you had a heads and cam done on that car. I had a 79 camero z-28 back in the day that would overheat as summer temps would occur, I tried everything to get that car to run cooler to no avail, sometime after selling that car, I found out that the factory had installed the wrong head gaskets that had smaller coolant holes causing the problem. Hope that's not the cause of your overheating problems, only mentioning it because it's something that happened to me. Good luck.

dmaxx3500

you really need to r&r the rad and a/c cond,and clean out the cooling fins,and get the inside flushed as well,

and how long ago did somebody replace the thermostat?[and what temp therm?]

you need to start with the basic's

leadfoot4

Although most don't recommend it, I did install a 180* t'stat in my '01, back when swapped out the balancer, since I also installed an LS2 timing chain, "since I was in there". Mine runs at 185-187* all day long, as long as I'm moving and have airflow. If I idle it, or get in slow moving traffic, however, it'll run up to 205* in short order. But as soon as I'm moving again, it will come right back down.

neutron82

when both fans were on at 187 were they at low speed or high speed?... the way the fans are wired it is possible for both fans to work on low speed and one cut off at high speed if you have a problem... the higher pressure cap probably only helped a little but I think you still need to address something personally, those temps just seem too high for a 75 degree day... when cruising do the temps come down or do they stay at 220+... for every psi added on the cap it raises the boiling point about 2-3 degrees, so about 6-9 degrees in this case... there are 2 tools I recommend for cleaning the radiator without taking it out, the radiator genie and an air comb... the radiator genie comes with 2 pieces, one can be used with air and the other with water... the air comb hooks up to air and is more like a flute, it is a thin piece with small holes in the end of it... the air comb is a bit more compact and will fit in tighter spaces, but both tools are adequate and put out a lot of pressure to get the job done

abraham

Yea, the radiator is quite dirty still. I can see stuff hanging out of there. I believe I put in a 160 stat, and it was probably around 15 years ago. Everything I did to the car was around then. Except I have refilled the coolant a couple times. Did not mechanically "flush" it but emptied and refilled. Have only drove it a half dozen times since then but even a quick drive(like 10 minutes taking it easy in overdrive) would result in overflow once I got back to the driveway so I was constantly topping it off. I was running around 200 while cruising. It always ran around there before the overheating issue. I all started about 2 or 3 years after the heads and cam. Overheated once. Then the next year it got to where I could not drive for aver an hour or two if it was over 90, then the next year it got to where if it was in the 80's I could not drive for over an hour then the fourth year it got to where I could not drive for a half hr in the 70's. So it was a gradual thing that would suggest a dirty radiator. The best I ever cleaned it was with a ac coil foam and getting under there and spraying out with a hose. I did make up a hose thingy with an elbow so I can blow it out. I will look into the comb thing. I do agree there may still be an issue but I have not drove this car this much in 10 years and no overheating. So thats a big step. Its only 60's here today so I will take it back out when warmer and get some better numbers. Which looks like wed or thurs. Perhaps squeezing the hoses broke loose a partial clog somewhere in the radiator?? Stat should be fine if I can idle the car for 45 minutes and only be running 198 coolant. No?

abraham

Dont you want to blow the stuff out the opposite way they are comming in. Does not seem the air comb would be good at that cuz of the fans. I could feel a nice stream of air comming through the radiator when the fans were on and sticking my hand down inbetween the ac and rad. for what thats worth. I made up a piece of pipe with an elbow at the end to hook up to a compressor. Works ok. Just so damn hard to get at it either way. The ac radiator actually looks fairly clean. At least not stuff hanging out of it.

leadfoot4

Yes.

I should also add that I installed one of the "screens" that fits inside the lower air opening, ahead of the engine radiator/air conditioning radiator. I believe it is the one that was sold by Elite Engineering. It helps keep the big stuff out.

abraham

So I noticed some air/coolant, really just some bubbling comming out of this hose so I tightened up the hose clamp and it stopped. Then I noticed a crack in the plastic tube that the hose connects to (also a metal tube inside connecting the two). The bubbling was not comming out the crack weirdly enough just the hose connection. It is cracked. Is this a major issue? Will jb plastic weld bond this type of plastic? or maybe silicone or crazy glue. Its not broke off just cracked about half way. I would just get a new cap but dont want to lose my paint job. Worse case I need a painter to replicate the job. Any suggestions on how to fix or and least prolong the breakage. Also what is this line?

neutron82

yes but you can easily remove the fans, unhook the 2 connectors then push up to release the shroud tabs from the radiator and it will slide right out... then you can use whatever you have to clean the radiator... removing the air bridge and radiator top cover will also help you get in there

Ceedub53

Looks like your coolant recovery tank is damaged. That crack on the tube extending from the tank doesn't look good. You could try some JB-Weld, but if it were mine I'd replace it. Rockauto has new OEM ACDelco recovery tanks for $110.

abraham

Good to know. I had no idea it was that easy. Top cover has been off for years.

sstonebreaker

Although your fans are running, are you sure they're running at full speed? Reason I ask is because I used to own a 96 impala ss. One of the common cooling system issues on that car were the fans konking out. We'd replace the relays in the fuse box and the fans would come back on; but they'd die again real quick. Fix turned out to be replacing the fan motors as well as the fan relays. It was the fan motors that were aging and gradually running slower and slower while pulling more and more amps until the relays burnt out.

Check the fan relays in the underhood fuse box and see if the plastic on the underside looks burnt. If it does, replace the fan motors and relays. At the time I believe I was able to buy just the fan motor at Autozone a heck of a lot cheaper than the entire fan assembly.

abraham

Good to know. I will check. I'm not certain they are running at full speed but I believe they are. The sound like they are cranking pretty good. they stayed on the whole half hr I had the car idling. I can feel air running through the radiator. For now its doing good. Will have to wait till the weather gets warmer to know for sure I guess. Like I said though. I can drive the car now. Even get on it, and no overheating. Before I had to baby it in overdrive and it would still over heat just driving a few minutes. I drove it to the corner carwash, washed the car and drove home last year and it boiled over. Now I can drive in D and even stretch its legs and no overheating. Granted the temp was 75 and not 85 but its looking good. Is it possible the surge tank cap was totally shot and not pressurizing the system? Cuz its doing alot better. Unless squeezing the hoses broke loose a clog. The only thing I can think of for now.

kh400

Just install a new std radiator. They are not expensive on the internet and will likely solve your problem. Flush the block while you have the radiator out. That red GM antifreeze turns to gel if it is not replaced every three yrs or so. I change all my fluids once a yr. Cheap insurance. Good luck!