Mitsubishi Pajero Problems

You're right, a seal is meant to seal, not leak. My guess is that if is a weep and not a full blown leak the dealer will want to continue to "monitor" it, whatever they might mean by that. I would get on the front foot with them and demand that it be fixed, it is only likely to get worse and probably leave you with the bill to fix it after the warranty has expired. Get it fixed now and should be no further concern about it.

Timing chains do not need to be replaced regularly as timing belts do, so there is no requirement in the service schedule for such a replacement. But they do wear and can become slack over time, and when that happens they do need to be replaced. If you don't replace them in that situation you risk them breaking or jumping teeth on the drive gears and if either of those things happened you could do serious internal damage to the engine. I'd be inclined to follow your mechanic's advice.

That's correct, the 3.2-litre turbo-diesel engine has a timing chain, not a belt, so doesn't need to be replaced.

Clutches are a regular complaint item at Carsguide, but determining what is acceptable life for a clutch is difficult because it depends so much on use and that varies from owner to owner. I would regard 39,000 km as unacceptable in normal use, but to argue your case would be a long and frustrating thing to do and I would fit a heavy-duty aftermarket clutch, which should give you better service.

The Mitsubishi engine is generally sound and doesn’t normally use excessive oil. If and when they do it’s usually found to be worn valve stem seals, and it that’s the case you won’t find and leaks or see any sign on the tailpipe.

The trade tells us that there is no issue with your model, but make sure you fit a quality sequential injection system, such as the Impco one that Mitsubishi released as a factory option for the 380.

I don't believe so; they're mainly fitted to prevent water getting into the engine when crossing creeks and rivers etc.

If you removed the tensioner pulley when you replaced the belt I would guess you didn’t set it up correctly when you reinstalled it and the belt was loose as a result, and has jumped a tooth when you revved it. Check the belt again and make sure the tensioner is installed correctly and the belt is tensioned. While I think that could be the explanation it is also possible that the wire to the crank angle sensor has broken.

I too have read the claims made by makers of these chips as well, but I don’t have the evidence that confirms the benefits, so I would leave well enough alone. By your admission the Pajero is doing the job, so I wouldn’t change it.

The diesel engine has a chain, so there's no requirement to replace it as there is with a belt.