Freefallin

1. Coolant overflows through reserviour.

2. I cant fill up through the radiator because it shows that it is full or will take only a cup or two of coolant before it fills up. But if i disconnect the top radiator hose, the engine will take 2 gallons of coolant...which means that the engine was almost completely depleted off coolant even though the radiator suggested that it was full. So now i just fill up through the top radiator hose.

3. Temperature gauge will shoot up to hot while driving. When i immediately shut the car off, sometimes the top radiator hose will not be pressurized as it should be on an overheated engine. That could be due to very low coolant. The car will then take 2 gallons of coolant even though i had filled it up an hour ago.

4. A lot of times the temp gauge will only go up a quarter of an inch above normal or even not at all even thou the car it totally overheated.

5. I can hear the radiator cracking loudly when the car is about to overheat or is overheated. Its like loud banging/cracking noise that comes from inside the radiator.

So what could the problem be?? I figured since coolant was overflowing through the reserviour even after driving the car for like 5 mins or less after a stone cold start, it could be the radiator cap. Replaced that with a genuine one from the dealership just a few weeks ago...although that was for a different reason. Also replaced the belt cz i thought maybe it was not gripping the water pump pulley properly.

I usually notice after coming back to the car after shopping or whatever when i see a puddle of coolant under the car. Its right under the reserviour which means coolant overflowing.

The cooling system has no thermostat. It was removed so it could not be that. And yes, it IS completely ok to remove the thermostat when you live somewhere where 115 degrees is the norm. I know "theoretically" the engine should overheat when you remove the thermostat since the coolant is not being held in the radiator long enough for it to cool. But then that is just in theory. In practicality, it does not cause overheating because i have the same car (different trim) with the same engine that ive been driving for over 5 years without a thermostat and it has never once overheated or given me any cooling problems. Even the car before that had no thermostat and it gave me no problems. It is a common practice here to remove the thermostat. Even the radiator shops suggest doing so. Reason i am making this clear is because i dont want you to think the problem im having is due to the lack of thermostat. I assure you, it is not. Car had no problem without a thermostat for years, that cant be it all of a sudden. And if it is hard to think otherwise, then just "assume" it is not it.

Ive also already bled the cooling system. And head gasket is ok cz there is zero coolant in oil and vise versa. Plus ive recently done a compression test...all is good.

Any idea what is going on?

Engine: LS1

2QWK4RU 06 GOAT

iTrader: (1)

When you bled the system, did you get lots of air out?

Blackbob

iTrader: (1)

Raise the front end of the car ( jack stands would works ) and then repeat bleading process.

Freefallin

I removed the rad cap and let the car idle for about 40 mins. Coolant would raise up and overflow every 20 secs or so, then it would reside... like nowhere to be seen even with a flash light. 20 secs later it would emerge to overflow...slowly. Kept on filling up as the coolant resided. There were hardly any bubbles.

silver sin

I had the same sort of problem a couple summers ago. No matter what my husband did he couldn't seem to solve the issue of overheating. I seriously contemplated getting rid of the car due to frustration. However, we solved the problem by using EFI live to look at what temperature the fans were supposed to come on that were set by the factory. It was incredibly stupid how high the temperature settings were programmed to be before the fans were to come on. We set the fans to come on at a lower temp and the overheating issue hasn't occurred since.

So my suggestion is to find a tuner with EFI live access, and have the guy adjust the temp settings. Worked for me.

Wish we would have thought of it a lot sooner, might have saved me two thermostats, a water pump and a few jugs of antifreeze. Plus the stress of watching my car puke antifreeze any time it got a little warm. Good Luck!

Buzzmanb12

iTrader: (11)

If you are putting 2 gallons in at a time...You have a leak. Either one of the end caps on the radiator (they are plastic and crack), a hose, heater core, the reservoir or maybe even a warped/cracked head/head gasket/cracked block if it got hot enough.

Blown Goat

air locked??? mine was

ACCLR8N

I had a similar problem on my 05 that turned out to be a poor sealing radiator cap. Seems I was bending the little tabs taking it on and off. I'm not familiar with the overflow arrangement on the LS1s though.

As to the temp gauge, it is programmed in the cluster that it rises until about 86* C then it holds there and doesn't start moving again until somewhere between 104-112*. So you really can't tell the car is getting hot until it is just about to boil over.

luigiandme

iTrader: (2)

The 04's dont have a reservoir. The surge tank is part of the cooling system. If it's overflowing out of the surge tank, its your cap. If the system cannot contain pressure, boiling point increases and cooling capabilities are dramatically reduced.

Put a cap on it.