Originally Posted by sundancer
Hi guys! My small family and I have been traveling cross-country since June in our 1991 International DT360. It recently started making a mid to high pitch noise that only happens when we are driving up hill. The noise is non-existent at all other times. Describing the noise is tough. It's not a squeak or screech really. It's just higher pitch and slightly louder than the normal engine noise. Any idea what it could be? We're not really losing power anymore than usual when it happens.
if its a squeal it could be the fan or water pump as some state... however the DT360 has 3 belts driving the fan so you wouldve likely seen issues with your aire brakes or alternator charging... the fan clutch itself could be going bad..
does this sound gradually come on as you start up a hill? or is it pretty much right away when you punch the accelerator to the floor. (within say 5 seconds or so?)
the turbo will make a high pitched "whistle" when you are on the throttle hard, however it happens fairly quickly once you punch it and you get your RPM up a bit...
if you have an automatic transmission (AT545) and you pull a hill hard enough and slow enough that it downshifts 2 gears it definitely makes a whine at full load in 2nd gear..
since this just started it could also be an air leak somewhere.. perhaps an exhaust leak around the turbo or a pinhole leak in the intercooler?
P.S. I just bought a 1991 Carpenter wit ha DT360. what kind of bus is yours?