1999 Chevrolet Silverado

[Gatores]

I have a 1999 Silverado with the 5.3 V8 with 200,000 miles that is buring coolant. Which in turn makes the truck overheat. There is no signs of leaking coolant just seems to be buring it. Any ideas what I am up against?

Thanks

Rick

[Scott K]

More then likely intake gaskets, or possibly head gaskets. Perform a pressure test on the cooling system to make sure there are no external leaks, then do a HC test on the cooling system, to see if the head gaskets are leaking.

[Macgyver55]

The 5.3 is a "dry intake" so that can be ruled out. You'll have to have a pressure test to determine where it is going. Dont forget to check things like block heaters, (if it has one) pressure cap and coolant reservoir hoses too.

[Scott K]

Nice catch

[Jeremy airjer W]

The throttle body still has coolant passages, it could be leaking although I have yet to see this on the 5.3.

[Gatores]

Are you leaning towards the head gasket then? Is that something a do it yourselfer can tackle?

[Jeremy airjer W]

how much are you losing?

[Gatores]

Roughly about 1.5 gallons in 30 miles or so.

[Macgyver55]

Roughly about 1.5 gallons in 30 miles or so.

Shouldn't need a pressure test to find that one....it must be pouring out somewhere.

Do you have lots of steam out the exhaust, coolant in the oil or any other symptoms?

[Capt. H (Ret.)]

Would this be a 5.3?? I thought it would be a 5.7 but then maybe it doesn't make any difference.

[Macgyver55]

Would this be a 5.3?? I thought it would be a 5.7 but then maybe it doesn't make any difference.

It definitely does make a difference, and the 5.7 did have coolant leakage from intake gasket problems, but 1999 had both the 5.7 and the 5.3.