Drove my 1 year old Isuzu D-Max Highlander 2WD 4 cab up to Buriram last week and about half way there I noticed a noise coming from roughly under the driver's footwell.

If I ceased accelerating, was coasting or just cruising on the flat at anything over about 60/80 then this noise would come like a loose exhaust but roughly in line with the revs and speed (not exactly mind you).

A couple of days after being in Buriram I toko it to Isuzu who had it up on the ramp and found nothing but said that it might be the wheel ?????

Now I think I might have lost some power which reads exhaust to me. The truck has 18,000 on the clock and full dealer service history every 5k.

Now I've no real idea what to do apart from get the grease monkey in the truck and show him whilst driving. They don't speak English and the missus knows bugger all about cars or mechanics.

Any ideas ? Could it be tracking ? Could a balance have fallen off the friver's wheel causing imbalance. I don't notice any pull to one side or the other, it brakes straight.

I just know it wasn't there before and now it is which means something is broken to me. Any help much appreciated.

You didn't say what the noise sounded like. However if it is a whirring type noise that increases with speed i would say possibly a wheel bearing maybe on it's way out.