96 LC - Coolant leaking into engine

[volos]

Hey I'm new here, but not to Land Cruisers or working w/them. I put a new head gasket in 96 LC (standard 6-in line 4.5) 80k miles ago. Yesterday I had a very sudden hard time starting (I've never had a partial hydro-block but I can imagine that's what this sounds like). I finally get it to turn and low and behold I'm blowing white smoke and the LC is shaking violently (I replaced the radiator 20k ago, don't think that has anything to do with it). After I'm looking around the engine for about 10 min (running) I notice I'm boiling coolant so I shut it off (have since replace the coolant).

I assumed it was the head gasket again, but when I popped the top off the block it looked fine. Not great. Now I assume my possible problems for coolant in the cylinders are:
1) Came through the head gasket
2) Came through a cracked or eroded head
3) Entered through some intake cooling / warming path (unlikely, it's never that easy, and I've really checked the lines)

Anyone got any recommendations as to how to really trouble shoot which problem it is? I was hoping visual inspection would give me the answer but nothing was obviously wrong. My biggest concern is the head itself might be slightly warped (no more than 1 mm). Or perhaps something I didn't think of (it was not blue smoke, it was definitely coolant there is no denying the smell)?

If I have to machine the block at all has anyone known to have problems with the tranny or hydraulics after that (I had a Subaru where that was a big problem). If anyone cares the millage is 286,321.6, of which I did about 215k.

Thanks,
Volos

 

[NLXTACY]

DO NOT TURN THE MOTOR OVER!!!!!

Pull the plugs, that will tell you right there. If you THINK you may be hydrolocked then pull all plugs FIRST and then turn over to get the coolant out of the cylinder.

 

[MARLIN375]

Do all the valves and pistons look alike (carbon residue and color)? Once you take the head off its pretty hard to diagnose exactly what was happening by standard means. It is basically just a visual thing now.

When you say it was boiling coolant do you mean it was pushing air/fuel (on the compression stroke) back into the overflow res.

When you replaced the head gasket on this truck 80k ago did you use the "new" toyota gasket?

it sounds like a no6 fire ring failure but I have not heard of any "new" gaskets failing in the same spot.

 

[volos]

First it wasn't a real hydrolock, I definitely wouldn't push that. My guess is a minor amount of coolant getting in some where.

Actually bought the HG from the dealership so I assume it was, I will track down the part # tomorrow. I really can't imagine it's a 6 leak, but since I have the block open I might just try swapping one..

What's blowing my mind is how even the wear looks on everything. Nothing is sticking out to say "here's the leak."

When I say the coolant was boiling, I mean that quite literally. Engine temp way spiked. When I cracked the spill-over it was boiling on it's own w/o taking air from the radiator. I know that sux hard, but was only for a sec. I'm going to try and figure out if the block is warped somehow.