• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

high pitched whistling

fspell220

NAXJA Forum User
Location
Attalla, AL
Hi,
The other day my 89 auto 4.0 cherokee started making a loud whistling noise. It is the loudest if you put your ear up to the radiator. Could it be that the fan is pulling the air so fast past the radiator fins it's causing it to whistle. I really don't know what this could be but it's so loud that you can hear it inside the jeep. Sometimes it will go away if you give it gas and then when it comes back to idle the sound will reappear. Any help is appreciated.
 
Actually I would try and listen to your pulleys, especially the idlers. Mine did the same thing and it was the idler pulley. I could hear my whistling over my stero. I couldn't stand it.
 
I tried to listen to then but you can't really get that close without taking your head off. Could the clutch fan make any whistling noises.
 
fspell220 said:
I tried to listen to then but you can't really get that close without taking your head off. Could the clutch fan make any whistling noises.

It could be the idler shaft that the clutch fan turns on, there are bearings inside the a/c bracket that eventually go bad. The clutch fan idler shaft bearing on my 90 is raising cain now that the weather has gotten cold here, just got a new bracket from the dealer, $85. The bracket comes with the shaft/bearings installed. I'm going to take the old one and try pressing out the bearings and replace them, others on here have tried and usually crack the bracket.
 
Did you modify your air intake at all?
 
Possibly an Idler,I use a pressurized spray bottle with water to shoot a stream of water on the belt then pulley by pulley till the noise goes away. Easy way to narrow down where the noise is. I usually use brake cleans in our shop pressure pump sprayers but not a very good idea
 
i am having the same problem and I am 99% sure that it is a fuel injector that has not got a good seal or seat on it. I can put a little pressure on my fourth injector and the whistling subsides substantially. keep us informed
 
Back
Top