Hi all

First off, I am a real technical ignoramus, but I have a problem that has been bugging me for a while (I am unable to get the truck to the garage at the moment so thought I'd ask on here).

When I turn off the AC the engine noise changes a notch and sort of "hisses" a bit more. It seems to come from the front of the block behind the radiator but I can't really pinpoint it. It doesn't sound like anything is going to fall off or blow out and it is not a major noise, but I don't think it should be happening and want to sort it. Obviously air con places different demands on the vehicle, but I find it strange that the noise happens when the AC goes off and not on!

Any suggestions would be helpful. I am overseas and my truck problem and lack of knowledge is irritating me. All research seems to point to extra noise when the AC is on!

 

Welcome to the forum

In south africa you would have the Ranger T6 version, we do not have those model Rangers here in north america.
Your Rangers are bigger and have different engines

But question is general enough to apply to any vehicle with AC(air con)

Best guess would be AC compressors clutch bearing is going out

When AC is on the clutch bearing is not used since compressor shaft and pulley are spinning at the same speed
When AC is off the pulley is still spinning but shaft is not so the bearing is being used, if it is failing then it would make a noise when AC is OFF and no noise when AC is ON

 

Thanks for your reply. That would make sense :) It is a small noise, enough to annoy me but not cause any alarm. Anything out of the normal I tend to pick up!