rhoff

I've spent a lot of time, and money, to try and get rid of any annoying whistle when my 2001 Jeep is stopped at a light. There is an annoying, intermittent whistle that cars around you can hear, the dog in the back of the Jeep can hear (and bark at!) but 2 different mechanics and a Jeep dealer couldn't figure out. I was told it's the alternator, which the mechanic replaced last week, but the whistle lives on! When you accellerate from the light, the whistle goes completely away. Has anyone ever heard of this, or know the problem. Thanks in advance, RHoff

jordan96xj

Check the brake booster vacuum connection. Its the rubber hose that runs from the intake manifold over to the large black drum shaped brake booster vacuum chamber that sits right behind the brake master cylinder. It is a check valve that has a tendency to whistle when the vacuum is strong. The vacuum is strongest at idle, and reduces as engine speed comes up.

Try to reproduce the noise with someone on the brakes in the garage. With your hand on that booster connection to see if it is coming from there.