Idler pulley, tensioner pulley, or water pump - What is this engine noise?

[geargarcon]

Video of engine sound

As the title says, I’m trying to diagnose this noise. It started a few weeks ago in the middle of some extreme cold. Coolant levels looks good, heat is running fine.

It does speed up with higher RPMs but I can’t tell if it really goes away or is masked by ambient noise.

Any thoughts on what the cause might be?

Thanks for your help!

 

[2001LC]

Most common and a good starting point, when checking the 9 pulley bearing, two belts and fan clutch in front of engine. That any one or more, many be failing.

 

[2001LC]

Fan bracket

 

[geargarcon]

@2001LC Amazing! I had also been wondering about the fan. I couldn't tell if I was imagining it, or if it visually stuttered a bit when the noise got bad in one of the videos. I tried wiggling/spinning it own my own and didn't feel any play or hear any noise.

 

[AlpineAccess]

Video of engine sound

As the title says, I’m trying to diagnose this noise. It started a few weeks ago in the middle of some extreme cold. Coolant levels looks good, heat is running fine.

It does speed up with higher RPMs but I can’t tell if it really goes away or is masked by ambient noise.

Any thoughts on what the cause might be?

Thanks for your help!

Have you pulled the belt and spun the pulleys? That would be the best place to start to eliminate the idlers and tensioner.

A mechanics stethoscope while the engine is running (watch out for the fan) will help diagnose whines that require accessories to be driven by the belt (examples: alternator, power steering pump, AC). My $20 lisle stethoscope has been a reliable tool for over 15 years and will pay for itself in a single project.

I find on cruisers that haven't had pulleys replaced as preventative, that its often more than just one pulley that is contributing some noise. My most recent 100, it was both the tensioner and the top idler. If replacing only the tensioner pulley, I'd recommend calipering the pulley and then ordering one of a similar size; as there have been some part successions where the pulley diameters changed to fit over different tensioner arms.

 

[geargarcon]

Shop just told me it needs a new Engine Cooling Fan Clutch and Engine Cooling Fan Pulley Bracket.

Quoting me $238 for the clutch, $366 for the bracket, and $955 for the labor.... $1,587 after taxes...

 

[2001LC]

What shop?

During timing belt service (TBS). Fan bracket (FB), is no extra labor and fan clutch nearly no extra labor ((4 screws (0.125hr)). So consider TBS, if near time required.

I'm, very tough on grading FB, during TBS. I just fail one with less than 24K miles on it. In fact I've, not reused a FB during TBS in years.

 

[geargarcon]

What shop?

During timing belt service (TBS). Fan bracket (FB), is no extra labor and fan clutch nearly no extra labor ((4 screws (0.125hr)). So consider TBS, if near time required.

I'm, very tough on grading FB, during TBS. I just fail one with less than 24K miles on it. In fact I've, not reused a FB during TBS in years.

Christian Brothers in Ken Caryl. I think I’m going to start using Toy-Auto Masters in Englewood.

My timing belt only has 35k on it. Wish the person I bought this from would have done the FB while he was in there.