Update: Heads are holding 40psi......

Now I'm even more confused. The block holds 25psi, the heads are fine at 40psi even. The head gasket never looked blown to start with and the cylinder that's full of water isn't even next to water jacket. I would say this HAS to be the block/sleeve leaking but if that was the case, wouldn't it leak at least SOME at 25psi room temp?

Bear in mind, this is an 04 with the sleeves that can't drop unlike older years so that's out of the question (I think).

Is it somehow possible that the water magically leaked past cylinder #7 next to the water jacket and didn't go in it but went into cylinder #5 instead? That seems so very unlikely.

 

Did you check that head bolt socket? They have been known to crack when hydrolocked.

 

Checked and just double checked the block including socket to 28psi. A good thought though, especially with that bolt being loose when I tore the thing down. Zip, not a single bubble except at the water pump a VERY tiny leak under that much pressure.

The manifolds I could check, I know they both have water but the lower portion seems to only have water in the front, the top portion if it has water, would share it between 4 cylinders at that point given the shared area after the throttle body.

I'm at a loss.....

 

I would do this with one modification, instead of using a modified water pump I would use the existing on and connect it to a running vehicle top radiator hose via the land rover T fitting. Put some brass barb fittings in the block drain ports at the bottom and route atf hoses in to the catch bottle with another Tee fitting. That way you run hot coolant through it to get it to temperature at full pressure.

Is the engine in or out of the truck?

 

^ Brilliant idea and ironic. I just did this a slightly different way but same concept a few minutes ago. I filled the block with hot tap water. I used a few heat guns in multiple cylinders in the block, after 10 minutes this got the block warm to the touch but even the sleeves were evenly heated, never hot, just warm. I used some tiny copper tubing, and put a torch to it with a 5 gallon bucket of hose water on the other end, this sucked the water up the tube and put it into the block in a slow controlled manner as the tube is only 1/8". I continued this water which was steaming hot letting it mix with the hot tap water. It took about 30 minutes to finally become a hot engine. When this happened, I put my air nozzle to it and held my finger with gloves on and a piece of scrap rubber over the other hole and boom, bubbles formed around one side of the sleeve in cylinder #5 only.

So, if you're going to do a leak test in the block HEAT THE BLOCK or it will possibly pass the test with a false positive.

So sad my engine is F#$%#KED. I guess now I have to decide, used engine, Turner short block, LS1 swap if ACE get's it done sometime this late summer as they expect to.

What is the going rate for a used but working '03 '04 motor? I will likely pull the block out and heat it and press the sleeves out, I'm curious to know what kind of failure occurred.

Many thanks to all who contributed, hopefully others who come across this will be able to better pinpoint their issues.

-Greg

 

if picking up a 4.6 pick one up from a P38. I've heard that the issues with the later disco blocks is due to not replacing machining as it wore down to save money. This is one explanation as to why the disco2 4.6 motors appear to have more issues than earlier manufactured blocks.

 

I've found the same, the trade off seems to be that anything earlier than 03 / 04 drops sleeves and anything that IS 03 / 04 gets a cracked block. My god Land Rover, what were you thinking?! lol When GM stopped production in 1962 of this motor because it had inherent flaws, it should have stayed dead. Why decades later anyone would want to revive it and not address those issue is beyond me.

 

true but pinning a motor before swapping it in is much preferred to cracking blocks haha. Good news is the motors are pretty much disposable with the cost of a used one. A hassle no doubt but beats spending a bunch of money rebuilding a flawed and underpowered motor. The LS swap I've been keeping my eye on for a while now as well but still taking a risk with a used motor and more potential issues then just finding a junked p38 with a running motor.

 

That's a fair point! I haven't been finding many running 4.6 motors it seems, I find plenty of Discos with non-running motors though! I will say this though, if I had to blindly choose a junkyard motor and my choices were a LR4.6 V8 or a GM 4.8/5.3, I sure as hell wouldn't pick the LR motor. lol

 

You see what I said here. This is all your doing I don’t care of the circumstances
first thing after buying one of these you need a ultraguage period.