Dakota Durango Forum banner

Squeal under hood - How to find culprit

3K views 17 replies 6 participants last post by  Hatchman 
#1 ·
HI all, happy new year.

I have squeal under hood. I've replaced tensioner, idler, waterpump last winter.

I squirt oil on alternator, no change, I squirt oil on power steering pump, no change. I squirt oil on idler, no change, I squirt oil on tensioner, no change, I squirted oil in my eye and still no change, just burning sensation.

I lost my coolant due to top hose coming off (I have no idea how that happened), I'm afraid my water pump may once again be unhappy and squealing.

Before I tear it down and replace, any advice on how to determine with some level of certainty as to what is making the noise?

I hate doing water pump in winter, no fun, last year it as 7 degree F out when I replaced.

Thanks all,
Joel
 
#2 ·
Take the belt off, and feel all rotating members as you spin them by hand. See which ones have roughness in them.

Whatever's wrong, strongly consider doing the tensioner, the idler(s), and the belt new as you fix the problem.

And one more thing - with the motor cold, and the belt off, start the car and see if it squeals. If it does, the problem isn't anything in the accessory drive.

RwP
 
#4 ·
Not really.

One more thing would be to use a mechanic's stethoscope and locate the squeal that way.

But I bet it's either a bad idler bearing, a bad tensioner bearing, or something else with a bad bearing - and you'll be able to feel it as you spin the offender by hand.

RwP
 
#8 ·
Pulled belt off this am.
water pump felt to spin as new (should I replaced last year, but did have water loss and hot motor situation last month)
idler spun as new (should as I replaced last year and all paint has not yet worn off)
Power steering pump spun as a pump should, no play.
Can't tell on crank and if that is source of noise then I've got other issues. I did not start without belt.
Tensioner pulley did not spin freely at all.
I took off, oiled with WD40, put back together and now silent.
I used stethoscope and the tensioner does not sound as clean as I'd expect (after oiling).
Will get new tensioner pulley today and with luck problem solved.
Thanks all I'll report back with confirmation.
Joel
 
#11 ·
Thanks for the posts.
replaced the tensioner pulley and all is now silent.
Belt looks to have had better days and likely will need to replace in the not too distant future.
What I'm thinking happened is that my top radiator hose came off, lost all coolant, bathed everything, including, I'm thinking, the idler pulley bearings.

I'm supper relieved that water pump is good, not fun to swap in the winter, did twice last winter.

Thanks all,
Joel
 
#13 ·
6 months is pretty good......the noise may be related or unrelated to previous issues.

have you replaced the belt yet?

seriously, run the motor for just a few minutes without the belt. it wont do any harm. 1 full minute is all it should take. it wont overheat (if relatively cold at startup) or drain the battery (unless the battery is really toast) ect, ect.

You could be right about anti freeze contamination in the bearings. I have taken idler pulleys, tensioners, ect out, delicately removed the bearing dust shields, inspected the bearings for wear and pitting, regreased them and put them back with no issues. BUT the bearings and races can have NO pitting or rough wear. If the bearing spins roughly, its toast.

JP
 
#15 · (Edited)
After you take the belt off, and before you start the motor cold, try all the pulleys.

Especially the idler and tensioner pulley(s). (I don't know if there's one or more idler; should only be one tensioner).

If there's any roughness in the idler/tensioner pulley(s), they need to be replaced.

If any of the others are rough, they most likely need to be replaced.

Even with a new belt, you need to check the belt tension in case the tensioner has gone week (which will cause the belt to squeal.)

On my Cougar (serpentine belt), I get the best results out of a Gatorback brand belt; most of the house brands squeal out of package.

(My Dakota is V-belted, so when my belts squeal, it's because the lead mechanic - ME! - didn't get it tensioned right. Or the AIR pump froze up, last time one squealed.)

RwP
 
#16 ·
figured it out. ended up being the tensioner, not the tensioner pulley, which i replaced first, but the tensioner itself. the spring had given up the ghost and was not tight enough. Put on new belt and still squealed, installed new tensioner and all is well. I figured it out, as after installing new belt and still have squeal I went to tensioner and gave it a twist to add tension (with motor off), then started and quieted down for a bit until tensioner loosened up again. New tensioner solved problem.

Glad this is done and I did not have to spend 150 on alternator as that was only spinning thing left other than power steering pump.

Joel
 
#18 ·
Was the same for me. Chased a squealing/chirping belt for years. Replaced many belts, squeal always went away and then squeal always came back.

Replaced tensioner (with a new belt) and running fine with no squealing for years now.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top