Issue that has me stumped..

[fireExplorer1]

Hey, im new to these forums. Had the car for about a year and a half now. Its a 1997 ford explorer 4.0 SOHC with 242k on it now. Now the issue that has me stumped it has a werid whine. Not the famous power steering whine. Its on the passenger side of the motor. Ive narrowed it done to a few options. It sounds like its in the area of the water pump, alternator, belt tensioner, and the idler pulley. Now the symptoms:

.A loud whine all the time (start up, idle, crusing speeds)
.The whine sound gets worse until it really sounds like something is going to blow up while crusing down the road until i let off the gas.
.Last night it made a grinding, like metal on metal sound for a split second, and went away after i let off the gas.

Its not overheating at all. there is no anti-freeze in the driveway or at work. and all the fluid levels are good. The belt has no squeak in it. Im hoping its a pulley. but i want to make sure and not just start throwing money around and it turns out to be a big issue. Any ideas?

 

[swshawaii]

Remove the belt and inspect all pulleys for binding. After that, run the engine LESS than one minute without the belt and listen. If the noise persists and you've eliminated the pulleys it's probably internal. 242K on the SOHC is uncommonly long without servicing timing chain tensioners, but your description doesn't fit that rattle. Harmonic balancer/pulley checked?

http://www.explorerforum.com/forums/showthread.php?t=302068

 

[fireExplorer1]

Nothing has been checked. There is a rattle. which im guessing thats the timing chain stuff. or if im lucky a heat shield. I am going to the auto store tonight to get a stethoscope and see if i can hear anything from that. im hoping its a easy fix and i can do it tonight as this is my daily driver due ot my lincoln being tore down. Im almost positive its an accessory. i dont think its as low as the harmonic balancer but how do i check that?

 

[koda2000]

my super-wild-assed-guess (as i have next to nothing to go on) is an alternator bearing, but the only way to get to the real answer is to do what swshawaii said. and with 242k on a SOHC with the timing chain death rattle i wouldn't be spending any more money than necessary to fix the whine.

 

[fireExplorer1]

well with that rattle it comes and goes.. sometimes it will do that and others i dont hear a thing. Does that sound like it?

 

[2000StreetRod]

4wd?

I've had better luck using a flexible length of hose instead of a mechanic's stethoscope to isolate to noise sources. If the noise is internal to the engine it will bounce around all over and be hard to locate. If the stethoscope or hose fails then you should follow swshawaii's advice.

Water pump seals don't always leak coolant when the bearings are worn enough to make noise. Alternator bearings can fail and make noise as can the tensioner and idler pulley bearings. Those sources can be eliminated by running the engine without the belt.

Do you have 4WD? If so, and the noise is internal you could be hearing the balance shaft chain. It is smaller than the camshaft timing chains and doesn't make such a loud rattle that often sounds like rocks bouncing around in the engine.

 

[Bobmbx]

Before you pull anything off, get a can of WD 40 with a straw. One at a time, spray each pulley while the engine is running. It'll be a bit messy with the fan blowing, but it'll prove if its a pulley. If the sound changes while you're spraying, thats the pulley thats bad. My guess is the lower idler or the tensioner based on where you say the sound is coming from. It could also be the belt itself. To prove that, with the engine running spray the smooth side of the belt with WD 40. It'll shriek like hell for a minute, then quiet down. If all squeaking is gone, it's the belt. The sound will come back eventually, though, until you replace the belt.

 

[1992fordgreen]

A/C clutch maybe? Random crap shoot.

 

[fireExplorer1]

Do you have 4WD? If so, and the noise is internal you could be hearing the balance shaft chain. It is smaller than the camshaft timing chains and doesn't make such a loud rattle that often sounds like rocks bouncing around in the engine.

I do have 4wd. Is that a pretty complicated fix? Or can i do it at the house?

And last night i went to the auto store and purchased a new belt, idler pulley, and tenisor pulley and it cured it. the ilder pulley was hard to turn. and the belt tensoner was wobbley like it was loose. Fixed all that and it runs fine now. amazing how the little parts can really worry you.

Werid thing about the idler pulley. the one i had taken off looked completly different then the new one. The one i had was a bit thicker and had groves so to guide the belt. The new one just was like a flat circle.

 

[koda2000]

I do have 4wd. Is that a pretty complicated fix? Or can i do it at the house?

And last night i went to the auto store and purchased a new belt, idler pulley, and tenisor pulley and it cured it. the ilder pulley was hard to turn. and the belt tensoner was wobbley like it was loose. Fixed all that and it runs fine now. amazing how the little parts can really worry you.

Werid thing about the idler pulley. the one i had taken off looked completly different then the new one. The one i had was a bit thicker and had groves so to guide the belt. The new one just was like a flat circle.

you bought the wrong pulley. smooth pulleys run on the back of a belt. grooved pulleys run on the rib side of the belt.

 

[fireExplorer1]

Sorry let me clarify. The one idler pulley i bought was smooth. And the one i had taken off was smooth as well, but it had ridges (if thats the right word). Looks like maybe to guide the belt in place? Sound about right?

 

[2000StreetRod]

belt tensioner pulley

If the belt tensioner pulley does not have grooves the serpentine belt will "walk" off the pulley and could damage hoses, radiator, etc.

You should not run the engine with a smooth/flat/grooveless pulley in the tensioner position.

 

[koda2000]

If the belt tensioner pulley does not have grooves the serpentine belt will "walk" off the pulley and could damage hoses, radiator, etc.
View attachment 76220
You should not run the engine with a smooth/flat/grooveless pulley in the tensioner position.

i think the OP's referring to a plastic replacement idler pulley that has shoulders to prevent the possibility of the belt walking off. it's okay to replace a smooth metal pulley with these plastic ones, but i prefer to stick with the metal ones.

 

[fireExplorer1]

i think the OP's referring to a plastic replacement idler pulley that has shoulders to prevent the possibility of the belt walking off. it's okay to replace a smooth metal pulley with these plastic ones, but i prefer to stick with the metal ones.

Yea. The auto store only had the plastic one, i pulled it out of the box and was like what the heck. Sorry for the confusion.