Random XJ Whistling Noise

[king282]

Well, to all of those who offered their insight and help with this issue, I am happy to say I finally got it figured out. It was the intake manifold gasket. I didn't even originally think to look at that, but after picking the brains of some Jeep-only mechanics at my local five-star Chrysler/Jeep dealer, we figured it out. I hope this helps all the people who said the had the same problem, and hopefully this will become a good refrence to all that stumble across it in the future on this post.

Thanks again! Bill

 

[outlander]

My 89 had a whistle......it turned out the water pump was worn,and the alt. and idler pulley bearings were whining.Changed all three and the noise ceased.
When I took the old idler pulley off and spun it by hand you could actually here it squeel.....just something else to consider when trying to track down a noise.

 

[Rocketman]

Noises can be VERY deceptive. Check all your pulleys. I had one that "whistled" till one day it exploded, throwing little bearings all over my garage floor and engine compartment when they hit the fan. $7 fix from NAPA.

 

[jcnoble]

I had that noise too. After I replaced all my sensors and fuel injectors to help pass smog it went away. I wonder if it could have been coming from the map sensor, it was sort of in that area. Maybe the vacuum hose there had a leak??