Disappearing engine coolant

[MidwestSS]

i just replaced mine in the SS. the gaskets were leaking slightly, and id only see a couple drops on the ground,, but the whole underside of the engine was soaked, but not yet dripping. .my coolant wouldnt go low.. so i just replaced it.. if you need a water pump for an engine, or if a 6.0 would fit, hit me up.. ill sell u my extra one for what I paid for it.

[GasGuzzler]

Umm....the 04 might have head issues. Pull a valve cover and look in there as you will likely not see it in the drained oil. Where is Steve?

Water pump to block gaskets are super common and only leak when COLD after sitting all night. Since the Dexcool has so much alcohol in it it evaporates and dries up off the floor and engine block and leaves no puddle in many cases. Look for pecker tracks on the front of the block, usually on the RH side of the engine, down towards the cross-pan harness.

[txarkitekt]

Umm....the 04 might have head issues. Pull a valve cover and look in there as you will likely not see it in the drained oil. Where is Steve?

HAHAHA!!! I am not laughing AT Steve, just the reference. I will bet that it is the dreaded Castech 706 head.

Dude--don't mess with anything else--replace the heads. Trust me. Also, while you have the heads off, clean the tops of the pistons cause they will more than likely be pretty gross.

[sierraman]

what is wrong with the 04 5.3's with 706 heads???? i would like to know.

[RedHeartbeat]

Google Castech Heads and see what you get.

[Beatdown Z]

HAHAHA!!! I am not laughing AT Steve, just the reference. I will bet that it is the dreaded Castech 706 head.

Dude--don't mess with anything else--replace the heads. Trust me. Also, while you have the heads off, clean the tops of the pistons cause they will more than likely be pretty gross.

What would you use to clean the pistons? Think I remember someone talking about using Kerosene.

[MYSHTBX]

they had a problem with the casting and the coolant would seep through the pores of the aluminum...and you would have yellow oil/coolant build up all in that valve cover... i replaced 2 sets when i was a tech at gm.. even if one side is leaking we would replace both....

[GasGuzzler]

they had a problem with the casting and the coolant would seep through the pores of the aluminum...and you would have yellow oil/coolant build up all in that valve cover... i replaced 2 sets when i was a tech at gm.. even if one side is leaking we would replace both....

Ooops and Steve's was the only one I ever saw.

[sierraman]

thanks for the info. we don't do alot of gm where i work and i haven't heard about the 706 heads until yesterday. so looks like i need to start another parts list.

[Frenchy]

We've had 3 trucks with Castech heads in the last week, one of my motors had them