1994 water cooled turbo cracked head questions

[chainslap]

Hi there, bit of a intro and question thread rolled into one here.

I'm from Arizona, but currently residing in New Zealand on a bit of a vacation. About a month ago I bought a 1994 4wd L300 with the 2.5 4d56t motor in it. Everything was great until heading over a pass when it started spewing coolant. Topped it off but it kept filling the overflow bottle and spitting it out the left side. So we checked the rad cap and thermostat and those were both functional. Then after doing some digging around and talking to mechanics here we came to the conclusion that the head is probably cracked.

Started pulling the head today and as I was unbolting things, on the backside of the head I noticed a short piece of rubber hose that I thought went into the head, but it is in fact plugged with a piece of steel...Did some more digging and realized this is one of the rare water cooled turbos.

Now my suspicion is that this head has been replaced with an incorrect one, and they just plugged the water line...ugh. Can anyone confirm that this line does in fact go to the block, and secondary question is where does the return line go to?

I can get pics up in the morning as well. Hoping that I can find the correct head and that the turbo is OK. This is honestly turning into a huge headache and I am close to throwing in the towel and scraping the thing since I'm here short term but I'm pretty mechanically inclined so I was hoping just a new head would take care of it, but it seems I keep getting deeper and deeper into this potential lemon...

Thanks for any help.

Geoff

[thedjjack]

my guess and it is just a guess is the Turbo will be fine without the cooling... I think it probably just attempts to keep temperature down.

You could splice the coolant from another source such as the heater system with the wrong head.

put a new head on and go have a vacation...

Remember it is a little diesel if adding fuel does not change the speed you are just poring diesel on a fire and the end result will be heat that cracks heads and melts pistons... lots of RPM climbing and watch how much you push the pedal down.

[chainslap]

my guess and it is just a guess is the Turbo will be fine without the cooling... I think it probably just attempts to keep temperature down.

You could splice the coolant from another source such as the heater system with the wrong head.

put a new head on and go have a vacation...

Remember it is a little diesel if adding fuel does not change the speed you are just poring diesel on a fire and the end result will be heat that cracks heads and melts pistons... lots of RPM climbing and watch how much you push the pedal down.

Thanks! Turns out you can order a different freeze plug for the head so I'll go that route. And the local Mitsi dealer actually has them in stock.

Got the head off, don't see any obvious cracks except in the injection ports. Anyone have some pics of where they typically fail?

I've driving in like an old lady from the get go, never going more than 90kph and letting it rev and not lugging it in the OD. NZ has some crazy steep passes so it sees some heat cycles regardless. I will say it's not quite as "peppy" as the 7.3 Powerstroke I had in the states, ha.

[Rattlenbang]

Unless you've had it since new, you have no idea how many overheat cycles it's gone through in the past. And if you don't have a EGT gauge, chances are you are doing the same on hills. Very easy to do, and it's a potential issue with every turbo diesel out there.

The crack that appeared in mine was tiny, a couple of mm; I couldn't even see it until my machinist pointed it out.

[chainslap]

Nevermind...

[Rattlenbang]

I'm loathe to say this, but ten to one timing is off and you torqued a valve into a piston. Easy enough to do. There's no way a bit of sitting should seize a crank.