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Unread 08-04-2010, 08:06 AM   #1
CoronaCowboy
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1991 YJ Wrangler 
 
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Help diagnose a strange Engine Noise...

Hi,

I've got a 1998 TJ 2.5l AT; it's my daughter's Jeep.

Last week it started making a weird almost grinding/gravely noise. At first I thought it may be the transmission; but ruled that out by listening for where the noise came from. To me, it sounds like it is coming from the power steering pulley or pump.

I took off the belt and turned all the pulleys and they seemed pretty quiet and smooth except for the PS. It had a little gurgly sound to it, but I thought that may be the fluid? Now I know that this is not the most scientific experiment, cause the motor turns it faster than I do, but I'm trying...

When the engine is revved and then slows back down, more of this strange noise occurs.

I've linked to a mp3 of the sound for you to check out. I know, it also has a valve or lifter ticking noise too... that's a project for another day.

http://www.chuckrock.net/media/2010-08-03_19-12.mp3

I told my daughter not to drive the Jeep till I get some more info on the problem...
Thanks so much for your help!

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Unread 08-04-2010, 08:57 AM   #2
Jeepsr4me
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i could not tell for certain but does it have exhaust leak?
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Unread 08-04-2010, 09:08 AM   #3
CoronaCowboy
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I don't think I have an exhaust leak, but I will check tonight and get back to you.

Thanks for the input.
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Unread 08-04-2010, 09:32 AM   #4
sherminator866
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doesnt sound good. when my water pump went in my old truck it sounded pretty bad too. just a thought. check this out it sounds similar: http://www.youtube.com/watch?v=2C4gQB8-64k
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Unread 08-04-2010, 10:32 AM   #5
CoronaCowboy
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Sherminator,

Sure sounds similar. Did your water pump turn ok by hand, or could you tell there was a problem?

Thanks!
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Unread 08-06-2010, 08:44 AM   #6
CoronaCowboy
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Quote:
Originally Posted by Jeepsr4me View Post
i could not tell for certain but does it have exhaust leak?
JeepsR4me: I checked and don't see an exhaust leak... at least not that I noticed at the engine to header or header to exhaust pipe connections.
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Unread 08-06-2010, 08:49 AM   #7
Jeepsr4me
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Does your engine have the single pulley that is used to tighten the belt? The bearing is known to go bad in them. with engine running spray a little WD40 in the bearing to see if stops making noise. Dont go crazy with it, dont want to wash out grease. But you will tell in about 2 seconds if thats it.. Alt will make noise too, they have bronze bushings in them that wear out over time. Again it will only show up with tension on the belt so free spinning does not always tell the tell.
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Unread 08-06-2010, 09:01 AM   #8
CoronaCowboy
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Quote:
Originally Posted by Jeepsr4me View Post
Does your engine have the single pulley that is used to tighten the belt?
The tensioner pulley is on the power steering bracket:


Is that what you are referring to?
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Unread 08-06-2010, 09:02 AM   #9
Jeepsr4me
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Yes the idler pulley.
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Unread 08-06-2010, 09:03 AM   #10
CoronaCowboy
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I'm going to give this a try this afternoon and see where it gets me.

Thanks for the advice, I'll post back with my results!
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Unread 08-06-2010, 09:08 AM   #11
R0cket
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if your PS pulley is making a grinding noise don't neglect it... check all your other pulleys first, then replace any one that is making bad noise... you DO NOT want a pulley to fail on you.... happened to me in my old truck... took the radiator, and a bunch of stuff with it.. $$$$$
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Unread 08-06-2010, 04:50 PM   #12
CoronaCowboy
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Quote:
Originally Posted by Jeepsr4me View Post
The bearing is known to go bad in them. with engine running spray a little WD40 in the bearing to see if stops making noise. Dont go crazy with it, dont want to wash out grease. But you will tell in about 2 seconds if thats it..
Ok, so I did a bit of poking around after getting home today. I tried a quick shot of WD40 on the bearing of the pully but it made NO difference in the noise.

But... That got me looking in more detail at the engine. I was looking at the belt where it comes over the fan/water pump. I noticed that, as the noise came and went, that I could see the belt vibrate and then stop vibrating when the noise stopped.

My assumption now is that it is the water pump. I went out and purchased a replacement, and unless someone tells me it is not that... I'm going to replace it tomorrow.

Thanks for the input everyone!
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Unread 08-09-2010, 08:18 AM   #13
sherminator866
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good luck with the pump. my pump was fine looking at the time but traced it down to the water pump. i think the bearings or whatever is inside just started to freeze up and wear out.
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Unread 08-09-2010, 08:24 AM   #14
CoronaCowboy
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Good news!

This weekend I changed out the water pump and that was the noise.
Now it runs as quietly as it should.

Thanks to everyone for their input in helping me fix this issue.

On another note. After I put the water pump in, and started the Jeep for the first time, the new pump squealed loudly for a second or two, and a little fluid leaked out... maybe a half ounce or so, then it was fine. The next day, I started it and no leaks whatsoever. Any ideas on this?

Thanks again everyone!
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