When at 2100 rpm or over in any gear, a low howling sound from engine comes into the cab. This can be very annoying when traveling long distances. Had dealer out for a ride, said he could not hear the noise. Could the turbo cause this noise? New air filter installed 4 months ago. Has anyone else had this noise?

My 01 makes the same noise. I suspect it is the fan. Mine also makes an additional noise when tha A/C is on at that rpm.

My 01 makes the same noise. I suspect it is the fan. Mine also makes an additional noise when tha A/C is on at that rpm.

I agree it's probably the fan.