My 2003 1500 5.3 Z71 (70,000 miles) is consuming coolant. No visible signs of a leak, but I've been adding about a quart of coolant every couple months (haven't compared mileage). I don't see any sign of moisture on the inside of the oil filler cap, but I do occationally notice a 'coolant' smell when exiting the cap after a drive. I'm planning to do a tune-up (oil change/plugs and cap etc) soon so we might find something on the plugs. I guess I'm wondering if there is a common issue with these symptoms...other than something like early head gasket leak.
Thanks

 

Could it have anything to do with the type of coolant you are using? I have a 2004 Silverado with the 5.3L engine and have had it flushed out (at the GM dealer) two months ago. I kept the OEM type of coolant (Dexcool) - rather than switching to Prestone or some other type.

I have heard that the two are not compatible and that any mixture of them is bad.

I have almost 78,000 miles now, and (Knock on wood!) it is not losing any coolant or oil between changes. I hope to keep this truck a long, long time.

Good luck finding the leak!

 

check your weep hole on your water pump. you may have a small leak from there. the water pumps on these trucks are known for failure at a early millage..

good luck

 

Hi there neabud,

Welcome to the Chevy Forums.

There's a problem with the gasket seals at the water pump with the vortec V8s.

The good news is they're easy to get at, and most large parts stores stock everything you need, since it's such a common problem.

Wow you made it to 70K, mine failed on me at 24K.

 

Thanks for the comments gang. Gives me food for thought as I get ready to figure things out.