blkZ286SPD

I just bought this car about a three weeks ago & am having a interesting problem. I loose coolant at higher rpms. What is happening is coolant from the radiator is being pushed out to the overflow tank and once that is full it is being pushed out from the overflow cap. I did a block test (with the blue die stuff) & at first it didnt change color, maybe a lil green (maybe couldnt tell for sure), but after about 20 mins of idleing with the cap off the radiator I noticed water was erupting like a valcano out of the radiator. I tested it again and sure enough it turned yellow right away. My question is It doesnt run above 190-200 degrees ever, no missfire dtc's, it only loses about 1/2 gallon of coolant thats it, no white smoke out the pipes, & no water in the oil. What is going on? I know I'm getting combustion into the coolant, but have no other symptoms of a blown head gasket. should I go ahead & pull the heads off & have a look see or what?

LS6427

iTrader: (2)

With the radiator cap off the coolant should never do the volcano thing.....thats exhaust getting into the coolant. I can run mine for 30 minutes with the cap off, it does nothing.

Its a blown head gasket....IMO.

I would just say you probably need a new radiator cap because the coolant was getting pushed into the overflow tank........but with the volcano thing....not good.

I guess you could try a new cap. Are you sure there's a t-stat in there?

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blkZ286SPD

Replacing the radiator cap was the first thing I did. That slowed it down because the cap that was on it was a 15psi & the oem that I bought for it was a 18psi. The next thing I was gonna do was check the t-stat, I do hear a rattle noise there when I squeize the coolant lines, but still go back to the the dye turning yellow on the block/combustion test. So not sure what to try next. This weekend I'll look at the t-stat & if nothing there I may try to re-torque the heads. I hear the ls1 gaskets arent known for blowing, but the bolts do strech & come loose. Just wondering if anyone has every had a similar problem like this

BRUTL

iTrader: (27)

Coolant system is getting overpressurized. Know how that happens? Blown head gasket. The hydrocarbon test coming up positive (turning green or yellow) should have been your nail in the coffin. It detects hydrocarbons built up in the cooling system. Know where hydrocarbons come from? Combustion, and we all know where that happens. That's right, the combustion chamber. Sorry to hear about your bad luck, but its a perfect excuse to upgrade!!!

blkZ286SPD

True that, I am probably gonna pull the heads this weekend & order the Torquer v2 cam. While the heads are off I will do some porting on the runners & polish the exhaust & combustion chamber area. Thanks for the replies, I knew thats what it had to be just need confirmation I guess.