Front End Chirp When Giving Gas

Hi,

First off, I've been lurking around this forum for a while and you guys have inadvertantly helped me solve many a problem. I thank you much.

Now for my next problem: After driving into town tonight, I noticed a chirpping happening upon acceleration. I pulled over, put it in park, and when I gave it some gas, the chirping could be heard. It became increasingly faster and louder with increased RPM's.

Now, I really didn't notice anything wierd in the drivability department. What could be some possible problems?

I have access to my uncle's garage all day tommorow (will be changing the convertor and installing a cat back system and changing plugs) and would love to go in there with some idea on how to approach this problem.

Time is not on my side! I'm gearing up to go on long road trip early next week. Thanks.

BTW, we are talking about a 4.0 xj sport.

I changed my serp belt about nine months ago when i got the jeep.

And It doesn't really sound like an exhaust leak, at least to me. Chirp/squeak-like. ( The manifold was fine last time I checked, but I'll check it again just to be sure.)

I had my girlfriend hit the gas while I listened, But my aux fan (being loud as it is) made it hard to pin point the sound. I will say the area around the harmonic balancer and flywheel seems suspect.

I know It's hard to diagnose an explained sound. I'm just looking for possibilities. I'm just hoping it's not the timing chain.

Idler pully?

They like to chirp, and then they go.....

unplug the fan and listen to it at higher rpms. i do agree that it could be an idler pully or some other pully. but i would still take a look at the belt. they can o bad anytime iven if u changed it just recently. i put a new one on my xj and two months later it stared going bad cuz it was defective so

Another vote for the idler pulley..... I had one that sounded like a train whistle when it was cold out.

Is your a/c on when this happens? If so, then it is almost certainly the belt tension.

The ac has no effect on the sound. The belt looks ok to me, but i could be wrong.

So, there seems to be concensus on the idle pulley. How hard/time consuming is that job? Keep in mind I'm a no mechanic. It took me over 4 hours today to exhange my exhaust from the cat back and replace an o2 censor. (If that give you an indication of my skills . . .gettin' that effin' cat off SUUUUCKED!) Should I just take it to the shop?

Front End Chirp When Giving Gas
that could be taken different ways

I had a very similar problem about 1 year ago. I had the same chirp that changed with rpms, and the sound was somewhat inconsistent. I couldn't figure it out, until about 1 month later my water pump literally exploded on the interstate, which in turn blew the belt off, which in turn got eaten by the momentum of the clutch fan. Not a fun day. You should really look into getting a mechanics stethoscope, I found one at harbor freight for 2 bucks. It makes finding noises like that so incredibly easy.

pauldo39 said:

I had a very similar problem about 1 year ago. I had the same chirp that changed with rpms, and the sound was somewhat inconsistent. I couldn't figure it out, until about 1 month later my water pump literally exploded on the interstate, which in turn blew the belt off, which in turn got eaten by the momentum of the clutch fan. Not a fun day. You should really look into getting a mechanics stethoscope, I found one at harbor freight for 2 bucks. It makes finding noises like that so incredibly easy.

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oh lord! Sounds miserable. I'm going to be some 450 miles from home next week. If that happens to me somewhere in the middle of the woods of Maine, someone will have to die: either my girlfriend for complaining or myself in an effort to avoid her complaining.

Yeah, buying one of those stethoscope seems a wise investment.

In this case I think I'm gonna have to bite the bullet and go get it checked by a mechanic. I just hate not being able to at least diagnose a problem, even if i can't fix it myself.

I hope you get that figured out. I was convinced my sound was a bad idler pulley as well but it wasn't, as I unwillingly found out. Now, I'm not going to guarantee that's your problem (my w/p chirped faster/higher pitched when I did anything to change the load, like turn on the a/c or work the power steering and I don't know if that's what yours is doing). Mine was inconsistent though. I can tell you one thing though, I am 99% sure I could have pinpointed the sound with that stethoscope (which I have now...) and gotten it fixed before losing a belt as well (it was less than 2 months old ).

Firewater said:

The ac has no effect on the sound. The belt looks ok to me, but i could be wrong.

So, there seems to be concensus on the idle pulley. How hard/time consuming is that job? Keep in mind I'm a no mechanic. It took me over 4 hours today to exhange my exhaust from the cat back and replace an o2 censor. (If that give you an indication of my skills . . .gettin' that effin' cat off SUUUUCKED!) Should I just take it to the shop?

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You'll need to remove the serpentine belt. That's probably the biggest job. The idler pully itself is held on by one bolt. Remove the bolt, swap in a new pully, and tighten it back up.