Hello and welcome, I am needing advice on whether or not my belt tensioner needs replaced. Some background....supercharged 08 Mustang GT. Belt tensioner is a Steeda that replaced the original when it was supercharged. S/C and belt tensioner have roughly 33K miles.....car only has 43K miles. At cold start idle, I get a chirping noise and I noticed the belt tensioner was bouncing a bit too much for my liking. I did some garage mechanic investigating and sprayed (water) at the belt tensioner area and the chirping stopped until it dried out. Looking for advise to back up my thoughts. The belt only has 5K miles on it.

Attached video for reference.

Thanks in advance!

 

I ran across the same issues, discovered it was the belt tensioner. Anyhow, I highly recommend that you also replace the belt along with the tensioner, as your current belt is now also worn as well.

 

That tensioner bouncing around that much at idle seems... odd. A little might be present, but not that much. But then I don't run a supercharger, so perhaps that explains it. I'll have to go back out and start up Awesome and watch the tensoner on hers, but I can't ever recall hers bouncing around like that, and matter of fact it's just... there. Not moving. Perhaps I'm mis-recalling, of course.

Still, that exaggerated bouncing at idle is telling me there's something yanking the belt about, causing the bounce. I'd be taking the belt off and spinning each pulley/wheel in the mix, excepting the crank pulley of course. The power steering might be difficult to spin, but everything else should spin fairly easily. You'd be looking for something causing the pulley/wheel to catch, or roughness in the spin, maybe spin and hold a stethoscope or similar on a part of the thing you're spinning to listen for the bearings.

I have a feeling you'll find an idler pulley or such catching and causing that issue. And it would not surprise me if it's the tensioner pulley right off. Spraying water on it would 'lubricate' it a little bit, so that would jibe, if be really bad lubricant.

I agree with the belt replacement whenever the cause is identified and fixed, as the belt's seeing a little bit of extra work it wouldn't normally see, I'm thinking. Even with only 5k, if it's being overworked/overheated by friction, yeah. Best to just toss it. Your call of course.

For what my thoughts on that are worth. Hope it helps and hope you find it. Good luck!

 

Thank you gentlemen, I will have a second opinion, in person later this week. I will check on the idler pulley as well. Continue the info, but I will post back with a possible answer.

 

spray it with WD-40

 

Gentlemen?! Well, I never...! I'm a savage beast man, c'mon.


Standin' by awaitin' word!

 

Spoke with the folks who worked on/built the engine. They said the belt tensioner will have more movement due to the engine also have Detroit Rocker cams installed. I guess its the nature of the beast. As for noise, they believe the newer belt was not properly cleaned, thus causing the noise. I sent them the same video I posted here.

Still going to get a second opinion from another reputable performance shop. Anyone else have any input with this new information?

 

I would most definitely get a second opinion. As I don't buy for a single moment about the belt tensioner having more movement due to having Detroit Rocker cams. There shouldn't be any movement from what you described and if it does? then the Steeda tensioner isn't built well enough to handle the additional torque of the supercharger and Detroit Rocker cams. Anyhow, my car is also supercharged and recently had to replace my belt tensioner, as it also caused the very same chirping noises as your describing. I also did the water spray trick on the belt near the tensioner as well and sure enough the chirping noises went away for a few minutes and then came right back. Needless to say, the chirping noises haven't returned since replacing the belt tensioner. That being said, for your particular application, I would strongly consider either upgrading to the DOB Frankentensioner, Thump Racing Products or from American Racing Solutions.. The links are provided below if interested?

https://www.beefcakeracing.com/brand...ns/tensioners/
https://www.thumpracing.com
https://www.departmentofboost.com/pr...ioner-stage-i/

 

You, my man, is why coming to the forums can be a boon. Thanks for your input! I actually had a Roush Belt Tensioner in my shopping cart, but I will look into the ones you are suggesting. Thanks a lot and will continue to update!

 

Just bear in mind the ones I'm suggesting are going to be more expensive over the Roush and Steeda tensioners, but in the end will last much longer and be able to handle the additional torque of a supercharged/built motor.

 

Thanks for the suggestions! I will most likely go with the Roush if its determined that the tensioner shot craps. It may be subpar to those you listed, however I really dont race the car, etc. So if it solves the problem...I'm good with it. If its lifetime is shortened due to not being as robust, then I will cross that road later. Let's hope this tensioner is the issue.

 

From my most recent experience, it was most definitely the belt tensioner. As for the Roush tensioner? it's pretty much designed in the same way as the Steeda tensioner, so I wouldn't count on the Roush tensioner as being any better. If I were you, I would highly consider going with the DOB Frankentensioner if cost is a concern? it's pretty reasonable at just $50.00 which also includes free shipping.
Like yourself, I also don't race my car which also has less than 30k original miles, but nevertheless had to replace the stock belt tensioner anyhow as a direct result from not being able to handle the additional torque put upon it from the supercharger

 

Yea, I hear ya. I may be shooting myself in the foot, but just hoping that it took 30k miles before it crapped out. If so, then I'm good with doing it again in 30k more.

Which tensioner did you go with from your list?

 

Also keep in mind that my car has just the supercharger, otherwise, everything else is still stock including the cams. So perhaps that's the reason it took 30k miles before my belt tensioner finally crapped out? but that's just a guess on my part. Anyhow, I went with a new stock tensioner, at least for the time being. However, If the stock replacement ends up crapping out in the near future? then I will be upgrading to the DOB Frankentensioner from the list I provided.

 

I see it has already been mentioned; I was going to suggest DOB Frankentensioner also