RaGe

Pictures attached.

The pistons look clean, the bore looks very good (shiney and has a nice cross hatch) and the heads are in good shape (pending a visit to the machine shop)

however the headgaskets - which were not cracked or burned - have a buildup of sludge around the water jacket holes...

What should I do about the sludge in the water jackets? Leave it alone and bolt on the heads with new gaskets then do a cleanout? Or clean them out first? I don't want to take the motor apart and have the block hot tanked if I don't need to.. I want to put the damn motor in!

I pulled the heads because one of the exhaust bolts was broken off flush in the head. I tried to drill it out and remove it with an ez-out but ended up breaking the damn ez out!

Pics of head gasket attached! I'll follow up with pics of the pistons/top of the block later.

bingo

iTrader: (2)

That is how one of mine looked when I got my engine. I pulled the heads to install springs and to check the bores. I cleaned up as much as I could and installed That was 4 years ago and I haven't had any problems.

Klortho

That is what happens when someone mixes the green (non-prestone mix with anything anti-freeze) with the Dex-Cool, it turns into a glob of black goo

LT1guy

iTrader: (1)

The brownish goo (looks like mud) is a byproduct of the DexCool; I have seen it even on LT1s (like mine) with low miles and the proper coolant from day one. Some say its caused by air in the cooling system, not sure about that, but if it were mine I would put it back together, do a thorough coolant flush, and get every trace of Dex Cool out of the system. Its known to corrode gaskets, form sludge, etc. I have been using the green stuff in my SS for the last two years with no ill effects.

bingo

iTrader: (2)

My LT1 is a 94, what year did they switch to dex-cool? Mine had the green stuff in it.

LT1guy

iTrader: (1)

They switched for 96 I think; my 94 and 95 both had the green, the 97 had DexCool.

TwiSSted

That is correct.
The "mud" found is also normal.

88blkbird

Either coolant is fine as long as the other is thouroughly flushed out first. The waxy sludge is normal with dexcool, most commonly found in the coolant reservoir, it is typical over about 75,000 miles or so, though it will vary, not sure whether or not replacing it at 60,000 will prevent this or not.

blander66

the reason that dexicool causes that is GM was having problems with coolant system leaks so they put stop leak in every car using dexcool from around 94-97ish. It tends to build up in the heater core and block it up.

LT1guy

iTrader: (1)

It won't. I replaced mine far before then (drained it during a cam swap), and it still did the same thing. I'll take the old coolant that doesn't cause sludge buildup in the cooling system...its a real PITA to get out!!!