I recently had the motor on my 1985 Mitsubishi pajero turbowagon rebuilt. (4D55) 2.5D Auto. With only just over 6000km on the clock and on my return trip from the Kruger Park to Newcastle I encountered Nelshoogte just outside Barberton. Leading up to the event I noticed over the 5 preceeding days that the idle had become lumpy and she battdled to start and took slightly longer to start each time. I resorted to using the glow plugs at each start even though the engine was at running temp.
Driving from Malelane I noticed her running at about 100c but the original spec temp gauge was around mid range so I wasn't too concerned. However once I was going up Nelshoogte I noticed the dash temp had risen slightly and looked over to see the VDO unit registering 120c. With nowhere to stop and a line of traffic I had to slow down to about 40kmh to get over the top where I then coasted down to Badplaas. Temperature had then returned to about 90c, but there was absolutely no power and the engine was idling as if a mounting had come off! I switched her off and checked liquid levels.
She wouldn't start up again and only after running the starter for about a minute did she eventually fire. I crawled at 20kmh to the closest mechanic who first thought it was the turbo but when I mentioned it was just overhauled and that she wouldn't start he said it was definitely the diesel pump.
I proceeded home from there with an average speed of 25kmh to Ermelo with a cloud of black smoke on the hills and no power. A call to the guy who did the overhaul was done first to ensure that there was no more damage in doing this. His advice was do what I can as he suspected a burnt piston, but not being there meant he wasn't sure.
After Ermelo I was able to get up to 80kmh at times, she had more power but I didn't want to push it but it went it cycles and I would often end up doing 20kmh. In Volksrust I let her idle and she would be lumpy then idle smoothly in cycles, I dared not switch off in case she didn't fire (which was wise since I tried to start her this morning and she wouldn't fire)
I suspect that the diesel pump is the cause of failure here. Once all was cooled the next day I checked fluid levels. The Radiator had pushed out fluid into the expansion bottle and the top tank was dry so I filled the radiator with the overfull expansion bottle and it topped up with enough fluid in the expansion bottle to reach the low mark. There was no oil on the dipstick. I topped up with 3l of oil and it was then slightly overfull. My assumption here is that the rings collapsed due to it overheating caused by the faulty diesel pump, thus burning off the engine oil in the process.
In hindsight it is said I should have immediately pulled over, but unless you have been on Nelshoogte you have no idea how hectic it is being in a car doing less than 40kmh with a stream of traffic behind you on an unfamiliar road with corners from hell. I also maintain it was already too late!
Would the diesel pump be the cause of overheating and is my assumption correct that a complete overhaul of the engine again be my best case scenario?
thanks
warren[attachment=0]Kruger Park 03082011 132.jpg
(You mention 4d55 and turbo.
If it has a turbo, it is the 4d56 TD engine, not the 4d55.)
It does not sound good
The first would be a thorough diagnosis by a GOOD diesel mechanic.
When it comes to re-building, you have different choices:
If it has a turbo, it is the 4d56 TD engine, not the 4d55.)
It does not sound good

The first would be a thorough diagnosis by a GOOD diesel mechanic.
When it comes to re-building, you have different choices:
- rebuild
- Mitsu 2.5 engine / sub (hard to come by)
- Hyundai Bakkie engine ('exact' copy of the 4d56 Mitsu engine)
I stand corrected it is the 4D56 engine.
As for the guy who overhauled it. He is a specialist and I have had good work done by him for me before. He stands by his product and service. The motor has a 20000km or 1 year guarantee on the rebuild. I do know about the Hyandai motors, but one guy in our town bought 3 dud motors. I didn't (and definitely don't now) have the budget or the time to go that route.
Having a limited budget is a pain in the butt. I have been mulling over what went wrong and come back to the same conclusion that the diesel pump is the culprit. However we will see when it is dragged to the workshop to be torn apart!
As for the guy who overhauled it. He is a specialist and I have had good work done by him for me before. He stands by his product and service. The motor has a 20000km or 1 year guarantee on the rebuild. I do know about the Hyandai motors, but one guy in our town bought 3 dud motors. I didn't (and definitely don't now) have the budget or the time to go that route.
Having a limited budget is a pain in the butt. I have been mulling over what went wrong and come back to the same conclusion that the diesel pump is the culprit. However we will see when it is dragged to the workshop to be torn apart!
Good news on the motor. Cylinder head gasket failed between No3 & 4 pistons. I am so so chuffed. The head was toast though so the engineering shop who did the initial rebuild is sorting it out! By some miracle there is no further damage to the engine.