Illini82

This is the second time I've had the upper radiator hose come off my 01 C5. It was about 3 months after I bought the car that it happened the first time, and about 1.5 months since then when it happened tonight. Has anyone experienced this problem or have any idea what it could be???

The hose isn't really that tight, so I can't imagine it is slowly being pulled off by the engine rocking. I also find it hard to believe that random pressure spikes are happening.

Please, someone help me. This is really annoying!

Illini82

bump

Still can't think of a problem

LS1-450

iTrader: (33)

You're talking about the 2" upper radiator hose that runs from the radiator to the water pump? Is your radiator cap spring stuck closed? Make sure that it's allowing coolant to overflow into the overflow reservoir.

If the hose clamp is tight, what you're describing is almost hard to imagine. Even if the radiator cap spring is stuck, I wouldn't think that enough pressure could build up to make the hose pop off. Well, unless your coolant is low & steam pressure is building up against the hose connection, then maybe this could happen if there's no lip on the radiator hose nipple or if the hose clamp is shot.

Illini82

The thing is, when this happened last night I walked to a gas station, got some water, and filled up the tank with bottled water. it was fine to get me a half hour home. When I got home I was able to squeeze the top hose with the engine off and hear and feel it pushing fluid into the tank.

I just had the system flushed and filled at the dealer about 1.5 months ago when it happened the first time. I'm hoping they filled it to the correct amount then, and since then I haven't EVER noticed any coolant below the front of the car. So if it is leaking, it's VERY SLOW.

Thanks for the response, let me know if you can think of anything else.

LS1-450

iTrader: (33)

I don't mean that it's leaking. Well, at least not externally where you'd see it. If the air was never purged from the cooling system, your gonna make steam & possibly warp the top of number 1 & 2 cylinders because of the hot spot created by the air pocket.

After the car cools down & the coolant drains back into the engine, open the radiator cap. The coolant should be to the top of the radiator & should also be overflowing the radiator becaue when you remove the cap, the small amount that remains in the overflow (by design) will overflow out of the radiator. Also, keep the overflow container filled to the low mark on the side when the car is cold. Don't let the coolant level get below this line.

My guess is that when you remove the cap, the radiator will not be full. This is your air pocket that is allowing steam. The air is there either because it was never purged or the coolant is leaking through the head gaskets. Remove the oil filler cap. Is there white residue on the under side of the cap?

staringback05

iTrader: (8)

check and see how its flowing...let it warm up and just watch the flow....

DaddySS

Generally overheating and pressure build up will make the hose pop off, rarely unles you have other symptoms, head gasket leak will build pressure in the system. If a shop puts a pressure tester on your system, they should be able to see if it is building pressure as it runs.

Illini82

Well I'm sure there is going to be some air in there now because I didn't remove the air after I reattached the hose on the side of the road and filled it back up with water.

So wouldn't you have thought since it easily got back up to temp before I got home that it would have blown again? Someone correct me if I'm wrong but if it is building up that much pressure shouldn't the overflow tank cap be blowing off the pressure. This weekend I was going to try using my air compressor to put pressure in the overflow tank and make sure that valve was working. I guess that could answer some questions.

All your suggestions make sense, but what doesn't make sense is why it took 1.5 months to reappear and that it takes place during normal driving. If I do take it to a dealer, I'll make sure they refill the system properly and check the pressure.

With regards to the oil filler cap, I just changed my oil this weekend so would there still be a residue? What is this residue from? Would this indicate the head gasket leaking?

jam01

first thing you should have done was call the dealer. and i would still do so, just explain your situation they should (better)take care of it. as far as residue on the oil cap that could be an indication of other problems, head gasket or just condensation from the season change. if the dealer wont help you you can call gm or email them with the problem. sorry i cant remember the phone #,ive been out of the busine's for a couple of yrs. hope that helps you