Thread: Another overheating post..

I started to overheat and changed The coolant elbows then later needed to change the lower intake gasket. It was running great for a couple weeks and now it's getting warm again. I am loosing coolant. I have to add a splash every other day. When it's really warm I can hear a hissing from left side. I can't tell if it's by the belts and elbows or closer to the front by the lower rad hose. I can't see a leak anywhere. COuld removing the elbows to change the lower intake have broken the new elbows? I did oil then before installing both times. Plz help thanks

if you can hear a hiss, i'd start with rechecking the elbows. did you clean the holes real good? where the elbows go, both sides, the bracket as well?

Originally Posted by scottydoggs

if you can hear a hiss, i'd start with rechecking the elbows. did you clean the holes real good? where the elbows go, both sides, the bracket as well?

Clean the hoses that come out the back of the braket? I cleaned out the old elbows that broke inside the block and bracket. I might take it off tomorrow and check...

Originally Posted by 99PontiacGTP

Anything loud enough to hear a hiss is big enough to leave a puddle. Could be your A/C if you hear the hiss with the car off.

I assume you bled the system?

I did bleed it after every opening of the system. The a/c unit is around there but I do t think I've ever hear this noise before.

I replaced the gasket between the supercharger and manifold. The coolant portion had damage. After refilling coolant im still having to add a splash every other day and don't see a leak anywhere. Also if it needs coolant isn't it suppose to take from the reserve tank? Mine never has. Tank will be at full line and radiator empty... (while I was at it I clean the crap out of the supercharger and manifold and it's amazing!!!!)

Originally Posted by hitman92499

Have you pressure tested the radiator cap or replaced it? Without pressure in the system, the coolant will be able to evaporate since pressure in the system increases the boiling point. Also, a faulty radiator cap will make it so the cooling system never pulls from the overflow reservoir. Just a thought.

Interesting! I didn't think of that. That will be the next thing I try. Do shops charge to pressure test?

Originally Posted by matt5112

What part of the blower did you clean?

I used brake cleaner on the throttle body, supercharger, and manifold. I was very gummed up.

Im curious about the supercharger rotors and if their coating is still intact.

Also apparently gm had some issues with rad caps failing which aggravated dexcool to sludge. Didnt keep the cooling system full.

If the reservoir tank is full and the rad is empty, either the cap is bad or the hose has some type of blockage or pinched. If you remove the cap, can you see coolant flowing from the tube into the rad?

Originally Posted by 99XC600

If the reservoir tank is full and the rad is empty, either the cap is bad or the hose has some type of blockage or pinched. If you remove the cap, can you see coolant flowing from the tube into the rad?

It flows through that hose. Wow if I've taken my car apart 3 times and it's the dang radiator cap I'll be pissed! Well not really. At least I got to clean it out and change gaskets that if weren't broken b4 would eventually break. I'm gonna get a cap on break.

Just remember that the radiator cap is essentially another thermostat that is set to open at a certain PSI. If it doesn't open, the coolant won't have a place to expand when it's at operating temp.

Too see how it work's just put it on the bench and fill it with some water. Push the plunger down and the passages will be exposed and the water should flow out. This is how the coolant from the overflow tank flows into the rad.