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Braydenp1012 11-15-2012 07:12 PM

Jeep squealing/whistling
A little background..
My jeep has about 144,000 miles on it, I bought it used with almost all the stuff it has on it, already like that, so I don't know very much about all of it. It has been driving just fine, but it started making this weird whistle.
The problem..
It started making a whistling/ squealing sound, a real high pitched sound, and it only happens above about 20 mph when I press the gas pedal down to a certian point, it's not a metal on metal sound it's like an air-whistling sound. The pitch of the sound changes with how far I press on the pedal, and if I press the pedal down far enough, the sound stops, but then if I let back off the pedal a little, back to when the squealing started, it starts whistling/squealing again. But if I completely let off the pedal, it also stops. The pitch changing has no correlation to the rpm's, only with how far the gas pedal is pressed down. I know from looking under the hood I have a Afe cold air intake, and I have done a lot of searching to try to find an answer to this, I can't seem to find anything quite like mine, I have read that cai will make this noise, but why would it just now start doing it? So I went and tightened the hose clamps on the cai, and test drove it, with no change. It still whistled at certain points when pressing the gas pedal down ,above 20 mph. Because it doesn't make this sound while revving it in neutral, I can't find the exact spot where the sound is coming from in the engine compartment, but I do know it is coming from the engine compartment. What could this possibly be? Anyone had anything like this?

perkalator 11-15-2012 07:18 PM

Does your rig have a throttle body spacer.

Braydenp1012 11-15-2012 08:03 PM

No, it doesn't, I know where the throttle body is and looked for a spacer but there wanst one

ipath68 11-18-2012 11:06 AM

I have something similar to yours I posted a thread jeep is howling, mine isn't quite a squeal its that whistle howl noise.

lawndog 11-18-2012 12:14 PM

check your front driveshaft on the transfercase side I had a loud squealing sound i changed brakes and wheel bearings and still had a noise it was the double cardan joint

Braydenp1012 11-18-2012 08:14 PM

Thanks for the replys, I really hope it's not one of those driveshaft joints or u joints, cause I would have no idea how to fix that, and that sounds expensive to fix. Could it really be that? The strange thing is that it only makes the whistling/squeal sound when the gas pedal is in a certian position, so that being said would there still be the possibility of a driveshaft/ u-joint problem?

Mom sold the Jeepster 11-18-2012 08:40 PM

U-toobe has vids to show you how, the Haynes repair manual has some info, too. If you have time and the desire, go for it.

PDXJeeper 11-18-2012 08:49 PM

I bet it is the CAI, if you have the stock air box put it on and see if it changes. If you don't, try cleaning the filter. I hope one of these changes or fixes your noise.

Braydenp1012 11-18-2012 09:13 PM

I dont have the stock intake since i bought it used, buthaven't tried cleaning the filter, I bet it hasn't been cleaned in a long time, I'll try that tomorrow.

Thanks for the suggestions

Braydenp1012 11-20-2012 06:35 PM

Just got around to cleaning air filter. Not much dirt came out of it. I also took the whole cold air intake tube out and inspected it for cracks, it's perfect. Hopefully putting everything back on tomorrow and tightening all the clamps will fix the squeal.

Braydenp1012 11-27-2012 04:46 PM

Been driving it around since cleaning the air filter, and nothing has changed, it still makes the exact same squeal/ whistle sound. Not sure what to try now...

GoGetEm1994 11-27-2012 09:28 PM

I have the same exact noise as you!!!!! same with the gas pedal and 20mph. No idea what is causing this. i just turn my volume on the radio up and try to ignore it. The noise goes completely away once I am in 4th gear, I have no clue why.

Superdave1017 11-27-2012 09:34 PM

Same issue with me !!! Exactly the same

No cai though

iadoin 11-27-2012 09:42 PM

I'm in the same boat as everyone here. Mine though is at a certain point in 4th and 5th gear I get the high pitched whistling. Very annoying!

Braydenp1012 11-29-2012 06:02 PM

Yeah, very annoying. I tried to record a video of the sound with my smartphone while driving, but the whistle is so high pitched the microphone couldn't even pick it up! And my dad couldn't hear it very well so maybe it's something so high pitched that only young ears can hear it good. Anyways it's super annoying being that high pitched. Cleaning the cold air intake didn't change it at all. So maybe it's a vaccum line leak? Would the pressure in vaccum lines change with the amount of throttle applied? Cause if not, there must be some component of the intake that's causing the whistle.

Braydenp1012 11-29-2012 06:11 PM

Gogetem1994, Mine doesn't make the sound in 4th gear either(which is the overdrive gear according to the reading I've done online) so that's really weird. Or I might not have pushed the engine hard enough in 4th, cause of the speed limit being 50, and cops always crawling all over the road.

ohioviper 11-29-2012 06:45 PM

Vacuum leak on intake manifold. I have the same problem on my sons TJ. Take a can of carb cleaner and spray a little around intake and if motor speeds up you found your leak.

Braydenp1012 11-30-2012 07:32 PM

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I went out in the garage tonight and sprayed most of the little hose connections I could see connecting to the intake. I didn't have any carb cleaner, but I read that wd-40 would work too, so I tried that. After spraying the connections I could see, none made any change in the idle speed. Are there any specific ones I should try that I may not have checked due to my lack of knowledge on vacuum lines?

ohioviper 11-30-2012 07:51 PM

Try spraying along the intake to head where the intake gasket is. I would also use carb cleaner as WD never worked for me .PS thats a dam nice clean engine you got there.

Braydenp1012 11-30-2012 08:25 PM

Haha, thanks. Ill go buy some carb cleaner tommorow and try again.

AHLJWV 11-30-2012 10:09 PM

It's probably your intake manifold gasket. I've read some threads on here with the exact same symptoms and the fix was always replacing that gasket.

Braydenp1012 12-01-2012 12:46 PM

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There is a foil insulator thing on the top of the manifold, that is in the way for me to check gasket, is it okay to take this off?

Braydenp1012 12-01-2012 06:16 PM

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Ok, I went and bought some carb cleaner. I couldn't get any idle change while spraying. I sprayed all the areas shown in the photo, 3 elbow connections on the side of the intake manifold, around the throttle body area, the two hoses on top in the back of the manifold, and the crack where the manifold and headers connect to the engine. None made any change in the engine idle. Any other places I should try?

bykryd 12-03-2012 05:38 PM

When you find the leak use some SuperGlue to seal it and you save yourself alot of work and money.

Howard_Urick_3 01-29-2013 10:30 PM

Whistling Noise Solved!

I know exactly what is wrong with your Jeep. For the past three years, my 02 Jeep Wrangler X has been giving off this horrible whistling noise like nails on a chalkboard. It always started once I let my foot off the accelerator while I was on the highway. Always starting when I got over 50 mph. At first I simply could not figure out what the problem was and by the time the third year ended I had almost given up hope. The noise was unbearable. People could hear me coming down the street a mile away. It was even worse at stop lights.

Finally about a month ago, my jeep started acting up. There was no power in my acceleration. With each passing day, my jeep got slower and slower. I couldn't even get over 50 mph on the highway. My check engine light read P0432 - Main Catalyst Efficiency Below Threshold.

Obviously something was blocking my exhaust system from working properly. So yesterday I took apart my catalytic converter and discovered something extraordinary. One of my converters near the engine had completely disintegrated into the pipe and was now clogging up my rear converter causing the cats to become red hot while I was driving regularly. Due to the cats being red hot it melted an O2 sensor wire causing the engine code and the engine itself to run rich. After driving it for three years running rich it caused many problems including:

The idler pulley, tensioner, and the belt to go bad.

Washers on the fuel injectors to go bad with the valve cover gaskets top and bottom.

All PCV valves to go bad.

The battery died due to the delayed starts caused by the clogged cat.

Once I replaced all the washers on the fuel injectors the whistling problem was resolved temporarily for about five miles then the whistle returned. Although frustrated I knew now that I was on the right path. But before proceeding any further with the whistle I decided instead to fix the main cause of all my problems: the catalytic converter.

We put degreaser and soap and water through it and nothing came out the other side. Therefore to remedy the problem I "increased the flow" of the catalytic converter with a hollowed pipe. Once reassembly was complete I took my jeep out for a drive. And believe me when I say “what a difference!” My power was back. My jeep itself felt like it had been reborn. The only problem remaining was still the whistling noise. Only this time it was worse than before.
Opening the hood we finally discovered the culprit – the screw that holds down the intake and exhaust manifolds on the front of the engine near the first fuel injector!
Once sprayed with Tri-Flow "penetrating lubricant" and tightening of the bolt it resolved the issue. The whistling was gone. In conclusion, all of the residual problems which I had to fix originated from my catalytic converter going bad. You may not have all of the issues that I had but regardless I would urge you to check for these problems.

JeepReaper09 02-01-2013 03:54 PM


Originally Posted by Howard_Urick_3 (Post 3297315)
Whistling Noise Solved!

Opening the hood we finally discovered the culprit the screw that holds down the intake and exhaust manifolds on the front of the engine near the first fuel injector!
Once sprayed with Tri-Flow "penetrating lubricant" and tightening of the bolt it resolved the issue. The whistling was gone.

I didnt go as in depth as you did chasing the Whistle, but I did go straight to your Whistle fix, and tightend the screw holding on the intake and exhaut manifolds. No such luck for me though. I even went further and tightend all of the intake screws.

My annoying whistle happens only on the freeway above 50 MPH, and at a very precise throttle postion (usually at my cruising speed). Its not too terribly loud, but definitely noticable on the highway. GOGETUM94's idea with the radio seems to help, but when it comes to little noises, I this complex to not stop until I find the noice.

Anyone with other suggestions?

JRIEDY85 02-01-2013 04:13 PM

Could be an exhaust manifold leak. Mine was cracked and made a squealing noise. Not really a whistle tho. But check it out.

ScubaSteveTJ 02-01-2013 04:43 PM

if it sounds like the one in my ended up being the stationary idle pulley

JeepReaper09 02-01-2013 05:29 PM

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This may actually be my issue, my idler pulley is a bit corroded/rusted and has a bit of a roughness to it so I would imagine my replacing it would cure my whistle, and my belt would probably be happy with a replacement pulley as well. Any idea how much and how difficult this is?

Sorry for the multiple images of the same thing... damn computer!

ipath68 02-01-2013 05:33 PM

Super easy just pull the bolt holding it on. Go to a parts store get a pulley about 15-20$ check the belt tensioner pulley also. Those were the two I had to replace. If that one is bad too pull the torx holding the tensioner on then take it off and there is a torx on the backside. Same thing get a pulley and replace.

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