I just bought a 2003 4WD Silverado with a Vortec 5300 V8, Airaid induction, and Gibson catpack exhaust. Has 207,000 highway miles on it and runs and looks like new inside and out. Nice low rumble and no engine noise, no visible leaks or smoke. But there's a very slight sweet smell (coolant) when it's idling and you're outside - don't smell it in the cab through the vents. Loses antifreeze very slowly. Guy had to put some antifreeze in the overflow reservoir every two months or so. Am I probably looking at replacing the water pump? Like I said, engine runs perfectly. Only work done on it was a serpentine belt replacement. Belt has about 30,000 more miles to go before replacing again. Water pump has never been replaced. Really don't think I'm looking at a blown head gasket. No water in oil, or oil in overflow tank.

 

maybe pump, hose leaking, radiator leaking,

 

Checked the visible spots for hose leaks and didn't see any. Pump wouldn't cost too much. Is that a fairly easy DIY job? Is there easy access to everything in a 2003 Silverado?

 

Hi goodeknight,

Welcome to the Chevy Forums.

The Vortec V8 engines have an issue with their waterpump gaskets. If you check very carefully you'll probably find the leak at the gaskets rather than the center shaft seal which usually goes in a waterpump. Generally the seal goes to pot rather quickly, and gets very bad fast. With the WP gaskets, it's a small leak which doesn't change much over a long time.

The fan OEM fan clutch is a real brick, and the OEM waterpump had some issues with plastic parts. If you change the old waterpump, find an aftermarket fan clutch which is smaller.(They have ones literally @ 1/4 the weight.)

The good news, waterpump is easy to change, and most major parts stores have the tools and parts in stock, priced reasonably.