[Mcquill1]

Hi all,

I've got a harmonic balancer that I suspect is on its way out on a V6 1999 Amigo. It wobbles and has a what I can describe as a whirring noise when pressing the accelerator/engine under load. The noise is bad when the engine is started cold (less than about 50 degrees) and goes away when the engine warms up.

I'm trying to decide if I can do this work myself and have seen plenty of videos how to take the crankshaft pulley off. However, I don't see any videos how to install it on the web or on this forum.

Can someone please point me in a direction of any install procedures they have on this forum or YouTube? I'm open to any recommendations or trouble they've had personally doing this job. I'm guessing this is pretty straightforward, but want to make sure beforehand.

Thanks

 

[turnerd]

It's pretty straight forward. The tricky part is finding a way to hold the engine so you can tighten the pulley bolt -- do you have a manual transmission?

 

[Mcquill1]

I've got an automatic transmission. Any advice how to best hold the engine? Also, do you need to use a tool to install the harmonic balancer or is it as simple as tightening the bolt to get it into place?

 

[turnerd]

I recall just being able to bolt it down on the V6 Trooper. I’ve used an old drive belt and c-clamps, vice grips, and whatever else to keep the pulley from spinning

 

[Mcquill1]

Last question, is there a particular orientation that it needs to be installed? Thanks all

 

[turnerd]

It should fit over the key on the crankshaft, meaning it only can go on one way

 

[Mcquill1]

After some diagnostics with a stethoscope, the noise appears to be coming from the fan pulley area.

I disconnected the serpentine belt and the noise went away. How are some ways I can figure out what needs to be replaced? Do I need to replace the fan clutch, radiator fan clutch bearing bracket or the cooling pulley that attaches to the belt?

The fan spins freely and there's no noise when spinning it with the belt off. The only part I can find for sale online is the fan clutch bearing bracket so this is what I assume has gone bad.

Thanks again for anybody's advice and help!

 

[turnerd]

So you replaced the damper pulley and no more wobble, correct?

The whirring noise during warmup is typically the fan clutch-- it is designed to freewheel until the engine is hot and then kick in to keep it cool. It's louder on some vehicles than others and a part of normal operation. You can test it by getting the vehicle plenty warm (30+ minutes of driving) and then stick a piece of cardboard in the fan to try to stop the blades -- if it isn't slowed by the cardboard it's good.

The other possible suspect would be a bad water pump bearing but this would not go away when the engine warmed up to operating temperature. When was the last time the timing belt and water pump were replaced?

Can you take and post a video of the noise to make it a little easier to diagnose?

 

[Mcquill1]

So you replaced the damper pulley and no more wobble, correct?

The whirring noise during warmup is typically the fan clutch-- it is designed to freewheel until the engine is hot and then kick in to keep it cool. It's louder on some vehicles than others and a part of normal operation. You can test it by getting the vehicle plenty warm (30+ minutes of driving) and then stick a piece of cardboard in the fan to try to stop the blades -- if it isn't slowed by the cardboard it's good.

The other possible suspect would be a bad water pump bearing but this would not go away when the engine warmed up to operating temperature. When was the last time the timing belt and water pump were replaced?

Can you take and post a video of the noise to make it a little easier to diagnose?

I did not replace the damper pulley as I determined it was not making the noise. The wobble is pretty minor and doesn't seem to be a problem, for now.

I took the fan apart yesterday and suspected the fan clutch bearing bracket was the culprit of the noise; it was binding and made quite a bit of noise. I also determined the fan clutch was bad after your advice on how to check it.

Went to the junkyard today and found a fan clutch and clutch bracket in good condition for 30 bucks....and boom, its fixed!

Thanks for all your help!

 

[turnerd]

Awesome! Glad to hear it is fixed -- I would certainly monitor the condition of the damper and I suggest replacing it in the not-so-distant future since it is wobbling (indicates it could fly apart and can harm the engine by making the rotating assembly out of balance).