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Whistle under the hood

7073 Views 29 Replies 12 Participants Last post by  eekthekat
It is a little bit colder these days in montreal...
This morning I started the 1998 Rodeo (3.2/ Automatic/ 50K miles) and between 1900 and 3000 Rpm I hear a whistle comming from the engine. It cleared away as the engine warmed up. I did not push it at all so I can't tell if there is a power loss or not. First day it does that.

Is that the first sign of a leaking intake gasket?
Could it be a stupid idller that starts to rock not roll?
Anybody has ever seen this before?
Should I simply raise the volume on the radio or leave the truck in the driveway for a week to punish it?

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Honestly, I feel that most of the problems on this truck give fair warning *and* can be fixed for pocket change if you DIY.

Except for my ABS failure, everything else has been relatively simple for a home mechanic. Thankfully, the ABS failure was covered under warranty, not that I cared for the system. However, in the unlikely case that I ever decide to sell the car it is a nice thing to have.

112K miles on my '99 Passport
Gas gauge problem: Dropped the tank and fixed the fingers on the fuel sender.
Intake Manifold: Replaced both gaskets at 40K miles, no problems since.
O2 Sensor: Replaced bad sensor
Valve ticking: Happens every now and then so I change the oil and it goes away.
It's been smooth sailing otherwise *knocks on plastic wood trim*
It still idles smooth and I'm getting a consistent 18MPG driving to/from work near NYC in moderate traffic everyday.


Just one question here for everyone: Is WD40 an appropriate "lubricant" for a bearing? Isn't the stuff like 80% solvent?

I don't know the specifics of the bearing in the idler, but I'm guessing that it is a sealed unit and once it starts to squeal it should be replaced. I think you're risking a broken/damaged belt if that thing starts to seize up.

Glad to hear you resolved your problem!
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I personally wouldn't use it as a lube. It's good for getting into cracks and crevices to undo bolts etc but as a lube? No... Grease all the way baby!!!!

Howdy guys. Just a word on WD-40. Now, I'm not entirely sure this is true. But my grandpa used to tell me that the "WD" stood for "water-displacement". I know for sure that it works well for water displacement and it is high in mineral spirits. However, as a lubricant, it is crap. I personally like using it for cleaning adhesive and hindering rust from forming, and that's about all.

And yes, sealed bearings are just that, once their gone, that's it. V2, take everyones advice and just fix it and be done. At best, any lubricant is a band-aid fix. If that pulley locks up you could be asking for a lot more trouble. My 2 cents.

Pulley and bearing 68$ at the dealer.
Bearing alone 6.19 tax included at industrial bearing service
Labor 0$
I could have buy the lower quality bearing for 3$...
I replaced my idler pulley yesterday, the pulley with the bearing inside was only $20 at Carquest.
Its a canadian 6$....
Bad news, it is still whistling a bit, the bender pulley is still stiff (no side to side play) but it does not spin very long when I give it a quick shot.

step 1 will be the belt anyway, it is craked a little bit.
i've been having what I think may be a similar whistle in my 3.2l 2001 rodeo (71000 kms)... more like a woot woot woot real fast, its only been happening in the morning when its like -10*C... it sounds water pump related as well, when the truck heats up to operating tempeture i have no such whistling problem.

I'll have a listen next time its real cold in the morning (oh wait im sure that will be tomorrow :( ) and post my findings here as well... thanks for the great info on this thread!
Any of you guys have any luck fixing this problem? I have the same symptoms on my 98 Trooper. Whinning noise only when it is cold (below 40 degrees F). It's been like that for about two years but is worse this year.
has anyone fixed this problem. I have had the same thing happening for the last 3 days?
Assuming anyone is still reading this thread, more than likely it's just the serpentine belt whining a bit when it's cold and hard. Once it warms up it the little ridges on the underside loosen up and the noise goes away. You'll probably never hear it in the Summer, unless of course it's alwys cold where you live.

As the belts get older they are more prone to this, so if you've got a lot of miles you might want to consider this a warning to replace the belt in the next coupla months.
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