I have a 1996 Chevy Suburban C1500, 5.7 liter Vortec engine. I'm loosing a lot of anti-freeze and I can't tell where it's going. I can fill the reservoir up to the hot fill line and in 3 days it's nearly empty. Sometimes there's a slight odor of anti-freeze, but I can never see anything leaking. It's not going into the oil because I always check that. Where is my anti-freeze going?

 

you may be able to rent a radiator pressure tester from any major chain type store.

on a stone cold engine(like overnight) pump it up to 15 psi and go over the entire engine with a bright flashlight, look also for a white trail of dried up antifreeze.

if it were working it's way into the engine, you would find it inside the oil fill hole, take your pinky and scrape the inside of the top of the valve cover. if you find a thick sludgy mess, (i've heard it compared to butterscotch pudding here) you found your intake gasket leak.

 

Agree with Mike,

Very common problem for intake leak.

 

Park it on some cardboard after a good hard run. They usually leak best when cooling. The intake gasket for some reason on the newer sbc's have had a problem leaking, usually at the rear of the engine towards the distributor.
Hope this helps ya,
Billy