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Joel, Auto Service Technician
Category: Car
Satisfied Customers: 1603
Experience:  18 years and growing GM, ASE certified. Specializing in Chevy, Buick, Olds, Pontiac.ASK!
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Isuzu Trooper: I have a 2001 Isuzu It has developed a weird

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I have a 2001 Isuzu It has developed a weird whine. It seems to stop when I accelerate. but starts again when I let off the gas. It also seems to not want to always idle, acts like it might die. Not all the time though. This whine has gotten louder and I am worried something it about to break. I listened under the hood thinking it is a hose leaking, could seem to tell where it was coming from..??? Any ideas???
Hello and welcome.
The noise you are describing and the fact that it has an erratic idle and wants to die, tells me you have a vacuum leak. Vacuum leaks can cause a whine or whistle noise and affects engine idle speed- not higher RPM's.

A vacuum leak can come from many places...
Throttle body gasket, any numbers of vacuum hoses, intake manifold gasket, etc. The best way to find a leak is to spray some brake cleaner or carb cleaner in those and all areas where there is vacuum.
NOTE: stay away from any source of ignition like plug wires and coil, also stay away from the exhaust- the spray cleaner is VERY flammable. When the spray gets into a vacuum leak, the idle will surge indicating the source of the vacuum leak.
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Customer: replied 2 years ago.

thank you for getting back to me quickly... I appreicate your time and your answer seems likely. I am glad to think it is a leak and nothing to major. Just one more question... You say to spray carb or brake cleaner in areas with the vaccum? Am I to understand I just spray at the hose or manifold? I take it the car needs to be running and I want to stay away from ignition wires... I does not wish to sound too silly or ask a stupid question just never done this before and want to be sure...

Sorry, yes that is exactly correct. Not a silly question. Yes, with engine at idle, spay around looking for the leak.

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