53chevyfan

Hi, I've got a 2004 tahoe with a 5.3 that I got about a year ago. It was a good running low milage suv that was run off the road and rolled onto its side at a low speed. When I got it from an auction I put a battery in it and it fired right up and ran great. My plans are to use the motor and trans to swap into an older truck. I let it sit for the past year without touching it. Now I'm ready to mess with it and motor is frozen.... pulled spark plugs out and number 6 plug was all rusted out and coolant(or water) poured out. I filled cylinders with marvel mystery oil over the past month and tried to turn it with a breaker bar every week. Now I finally got it unfroze.
My question is where did the water come from? I've read about castech heads, is that the issue? The heads say 706 on them.
I've seen cylinders fill with oil in the past due to a truck flipping but I've never seen it happen with coolant and I did have it running after it was flipped so I doubt thats the problem.

Basically I'm looking for advice if this problem will happen again in the future and if so should I put new heads and gaskets on before I swap the motor
Thanks for any help

Che70velle

iTrader: (6)

It was froze so you know your at a minimum pulling the heads to take a look at just how bad the corrosion is in that hole. While it’s apart, you can easily see if it was the head gasket or a cracked head issue. You’ll know which direction to go once you see for yourself what went bad and/or will you need to have a shop do an overbore to clean it all up.
Your correct in assuming that the rollover had nothing to do with this. Usually there’s a lot of oil in the cylinders from a rollover, not coolant.

G Atsma

Possibly a victim of the Castech 709 head syndrome.
Like you said, disassembly will tell the tale...