03 chevy coolant leak

[sweet85chevy]

I have a 03 chevy silverado with the 4.8 and sometimes it leaks coolant and some times it doesnt i have been looking all around the motor for leaks i cant see any signs of wet spots any help with be great thanks

[blacstar]

heater core lines

[Ray@NP]

you might want to put a pressure tester on the cooling system, the water pump are known to leak all the time.

[dropem]

heater core lines

Im with him, it took me forever to find the small leak on my 05 and it turned out to be the heater hoses. Mine was actually leaking from a very small crack on the plastic fittings that clips over the metal lines from the heater core.

[bootlife]

I had a similar problem, turned out to be seeping out the weep hold on the water pump, almost couldn't find it it was so little of a leak

[stumpy]

Now I know where to really start looking. Past couple years mine has been leaking coolant but its not constant. Had the problem with the first real cold day went to heat up the truck and it wouldn't heat up again unless I revved the motor up from idle.

[danrock2384]

cracked heads, I have this problem as we speak on an 04 sierra 5.3

[danrock2384]

pull a valve cover, if its all yellow under it......sell your truck

[blacstar]

pull a valve cover, if its all yellow under it......sell your truck

its easier to just swap heads... and cost effective.

[1BAD6660]

pull a valve cover, if its all yellow under it......sell your truck

Lol.. easy! HIGHLY doubt its internal if its not been ran hot. Like was said its probably heater hose connections,water pump,radiator, but dont rule out freeze plugs or heater core..get you a pressure tester,mirror, and a good flashlight and park it on some clean concrete! Look over it SLOWLY