Isuzu MU-X Engine Problems
Why is my 2017 Isuzu MU-X struggling to make power?
If the new clutch helped the vehicle climb hills, then I dare say that was money well spent. As for noises from the engine under load, I’m afraid that’s a job for somebody on the spot who can listen to the vehicle and make an assessment. The noise could be major internal problems or it could be something as simple as a loose heat shield under the car. Even a loose or worn engine mount can create all sorts of mysterious and expensive-sounding noises and rattles.
Don’t forget, your vehicle came with a five-year factory warranty, so a major failure that is not the result of mis-use or general wear and tear (provided the vehicle has travelled less than 130,000km) is still covered by Isuzu.
Isuzu MU-X 2014: Service light and Vacuum Switching Valve availability
I wouldn’t go on a trip without fixing the issue. I'm surprised to hear that there is no stock in Australia, but I would reach out to Isuzu Ute Australia head office if you've only tried dealers so far.
UPDATE 12/2/19: Greg advises that this part was replaced under warranty shortly after this response was published.
My Isuzu MU-X has turbo underboost
What do you know about its history before you bought it? It could have occurred before you bought it, and just shown up now. It’s not something we hear about.