I'll update once I measure and verify, but I believe the Continental belt on Rockauto is a similar thickness to the Honda belt, at least the one I bought for my Accord seemed to be. I haven't noticed any sound on mine in the last 3k miles

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how thick was your conti belt?

 

Amazing John. Just goes to show you if it attaches to the motor, use the OEM part. Nearly every time I’ve veered from this advice it usually ends poorly. I’ll keep my eye on the replacements.


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Just recently replaced my OEM drive belt with a Bando belt.

Putting that belt on was a royal PITA compared to the OEM belt. Now I know why!

 

The Bando belt goes on with more difficulty due to it's cord structure. Posted on bando site instr. cheers!

 

Thank you John. Good info.

 

Good info..

I used the OEM when changing the tensioner. It was making noise. Changed tensioner and belt. No more noise.

Did anyone compared the Aisin Timing belt with OEM?

It could be the fact that the belt was fake.

 

Excellent observation and post John. Thank you for the details and sharing!

Just when we're tempted to use other replacement parts options, this is almost a continous reminder of the problem of counterfeit goods on Amazon and inferior sourcing/manufacturing processes used by otherwise reputable brands.

Would you consider adding this post to the Gen II forum?

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Excellent observation and post John. Thank you for the details and sharing!

Just when we're tempted to use other replacement parts options, this is almost a continous reminder of the problem of counterfeit goods on Amazon and inferior sourcing/manufacturing processes used by otherwise reputable brands.

Would you consider adding this post to the Gen II forum?

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Im not sure counterfeiting is always whats going on. Note that the oft recommended tk002 timing belt kit has a genuine aisin water pump, and OEM is aisin, but I and many others have noticed that the casting isnt as well finished as the one that it replaces. Unknown how that affects durability.
In this case does merely picking a mitsuboshi belt off ebay or amazon, assuming its genuine, mean we get the same belt as purchased at a honda dealer?
Maybe not. Most manufacturers have different quality level lines, and sellers may market it as OEM equivilent when its only the mfr. thats the same.

 

Thanks for sharing John. Good thing when I did my TB about a year ago and ended up using OEM belt.

 

As to why the thinner belt caused the tensioner to vibrate, I'm not sure. All I can think of is it tends to slap around a bit more than the thicker, heavier belt. It does go directly from the AC compressor to the tensioner so maybe there is a weird vibration there that causes the belt to slap a bit and vibrate the tensioner. For now I'm not able to duplicate the vibration and rattle anymore when cold so I'm happy. Just thought I'd share with everyone else since I've found nothing about anything like this anywhere on the Internet.

Sir John, I would tend to agree with your professional assessment that the different belt mass might truly make the difference in terms of harmonics (or damping it).

I've heard of this problem before (new belt, new noises), but never read of a solution until today.

OF

 

Sir John, I would tend to agree with your professional assessment that the different belt mass might truly make the difference in terms of harmonics (or damping it).

I've heard of this problem before (new belt, new noises), but never read of a solution until today.

OF

It's definitely a mass issue, when you look at the vibration of the individual belt drive components, the mass on the belt itself acts as a damper on the system. The tensioner is designed to be used with the mass of the OEM belt. So when a thinner belt is used, it makes sense that when a thinner and lighter belt is used, that it would vibrate a bit more because the belt is no longer as effective in dampening the vibration

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Man, I have zero idea if it would be helpful or hurtful.

I'm just truly amazed you found that item and it fits! This is especially considering that it is from a vastly different company. I mean, if you'd said, "Hey, I found this part on the Acurazine forums, and it's a drop-in replacement for the one on our Odyssey..." I'd be impressed. You found a part from a Cummins diesel!

OF

 

Good catch, but as Honda doesn't make belts, who is the OEM that makes the belts for Honda?

 

Mitsuboshi

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Great info! I’ve used 2 Napa belts now and had no issues. I believe they are made by Gates Rubber. If I have issues I’ll know to go to OEM. Thanks for the info again.

 

Yeah napa uses gates on both regular and premium lines. They are made in mexico now and didnt last me longer than other brands. The premium uses a higher grade of rubber.
FWIW if I have to buy parts from a local retailer Napa usually has the best quality, Autozone by far the worst, Oreillys a bit better but overpriced.

 

FWIW my previous vehicle was a honda passport (isuzu rodeo) whose 3.2 v6 used 3 accy' drive belts. The alternator/fan/crank belt is serpentine with tension adjust via alternator position. After installing a high output alternator I had major headaches with belt slippage, once they slipped at all it got worse quick as the belts glazed.
I tried every belt on the market, cost wasnt much of a factor relating to grip.
The Dayco premium belt with the W profile was the only belt that worked, the first one I put on lasted until I sold the vehicle.
I know this has little relevance to the issue John was experiencing but since he mentioned Dayco I thought I would put a testimonial in for them.
I might add that both serpentine pully bearings are easily serviceable with a grease gun and needle fitting, carefully inserting the needle next to the seal.
When I did my timing belt I noticed one bearing felt dry but otherwise turned smoothly. Greasing it surely saved premature failure.

 

It's been about 100 years since the Tacoma Narrows Bridge Collapse due to harmonic wind loading. It has taken nearly that long to develop the physics of how it happened and develop simplified calculations to model it on a computer. That failure didn't involve multiple rotating elements strung together with a flexible band that changes direction and speed. Rotational harmonic problems are extremely difficult to solve..... by other than experience and brute force methods.

My guess is that vibration showed during the initial shakedown of the engine prototype or during early production. It had enough deleterious effect that somebody stumbled onto (or possibly knew of) a solution to change the belt thickness and therefore change the harmonics of the system. It works and Honda changes the specifications for the belt to reflect. But, doesn't tell the belt manufacturers why the belt needs to be about 1 mm thicker. I am very confidant Honda chose the cheapest and easiest solution to the problem. To confirm one would need to interview the design team, if you can find any without a gag order or contracted silence or alive still.

Thanks for sharing the experience John. Every time my back hurts I forget that experience come in handy occasionally.

 

Having spent my time inside the auto cos. & the oil cos., I'd say it's all random.

 

Thank you John Clark for the information. You are one of the top contributors to this forum.

 

I really like jnissen's reply. Just use OEM parts. However, I'd like to offer a couple of conceptual insights as to what MIGHT be happening. It could be great to use an app on a phone or iPad (SPLnFFT) that can show pictures of sound frequencies and levels before and after the repair. The belt/pulley system is quite complex dynamically, with the belt sections acting as springs and the effective masses of the pulleys and tensioner acting as masses. The tensioner is a Mass-Spring-Damper (MSD) system on its own. In addition, the teeth of the belt on the pulleys deflect, modifying the effective spring. The resonant frequency of a system is approximately f(hz) = 2pi*sqrt(AE/L/M). A is the cross sectional area of the belt. E is Young's modulus "stiffness of the belt", L is belt equivalent length, and M is the "effective mass" of the pulleys & loads referred to the belt. So... at a first level, the area of the after market belt is lower. The belt is softer so E is lower. These tend to drop the natural frequency of the belt. However, the square root in the above equation tends to reduce these effects and is probably not enough by itself to make your noise. The tensioner has its own natural frequency. So if the natural frequency of the tensioner connected with the belt is close to the lower frequency of the belt and pulleys you can get an audible beat frequency that is the difference between the two frequencies. This is the effect of two people whisling high notes that are just a bit different from each other. You hear the difference between them. You mentioned a "rattling" sound". That can also be bearings that are shot in the pulleys (did you check the bearings in the pulleys?). You mentioned: "weird vibration there that causes the belt to slap a bit and vibrate the tensioner". They can make rattling sounds by again interacting with the belt. In this case the resonant frequencies could be higher since the pulleys and belt are creating their own resonance with lower effective masses involved. Belt slapping is yet another dynamic similar to vibrations in the string in a musical instrument - resonances love to absorb energy at their natural frequency. I hope no one tries to go down the theoretical path, as you may never return. Let the Honda engineers agonize over this... So.... I'm glad you found that replacing with OEM parts and with a new tensioner worked out.

 

I really like jnissen's reply. Just use OEM parts. However, I'd like to offer a couple of conceptual insights as to what MIGHT be happening. It could be great to use an app on a phone or iPad (SPLnFFT) that can show pictures of sound frequencies and levels before and after the repair. The belt/pulley system is quite complex dynamically, with the belt sections acting as springs and the effective masses of the pulleys and tensioner acting as masses. The tensioner is a Mass-Spring-Damper (MSD) system on its own. In addition, the teeth of the belt on the pulleys deflect, modifying the effective spring. The resonant frequency of a system is approximately f(hz) = 2pi*sqrt(AE/L/M). A is the cross sectional area of the belt. E is Young's modulus "stiffness of the belt", L is belt equivalent length, and M is the "effective mass" of the pulleys & loads referred to the belt. So... at a first level, the area of the after market belt is lower. The belt is softer so E is lower. These tend to drop the natural frequency of the belt. However, the square root in the above equation tends to reduce these effects and is probably not enough by itself to make your noise. The tensioner has its own natural frequency. So if the natural frequency of the tensioner connected with the belt is close to the lower frequency of the belt and pulleys you can get an audible beat frequency that is the difference between the two frequencies. This is the effect of two people whisling high notes that are just a bit different from each other. You hear the difference between them. You mentioned a "rattling" sound". That can also be bearings that are shot in the pulleys (did you check the bearings in the pulleys?). You mentioned: "weird vibration there that causes the belt to slap a bit and vibrate the tensioner". They can make rattling sounds by again interacting with the belt. In this case the resonant frequencies could be higher since the pulleys and belt are creating their own resonance with lower effective masses involved. Belt slapping is yet another dynamic similar to vibrations in the string in a musical instrument - resonances love to absorb energy at their natural frequency. I hope no one tries to go down the theoretical path, as you may never return. Let the Honda engineers agonize over this... So.... I'm glad you found that replacing with OEM parts and with a new tensioner worked out.

This is essentially what I was thinking

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I also had a great result from OEM drive belt. I bought my 07 with gate belt on it. It make squeaking sound every cold start for first ten seconds. Replacement of belt tensioner did not help. I also checked balancer. Finally just replaced with honda belt, noise gone since then.

 

Hey, thought I'd post a solution I found to something that has been plaguing me for quite some time.

This is on my own 2008 Odyssey Touring, J35A7 VCM engine with hydraulic serpentine belt tensioner. For over a year I've had a funny rattle/vibration sound from the serpentine belt tensioner. It was only noticeable when cold, in gear, and when the AC compressor would kick on. In Park it wasn't as noticeable. I could go under the hood and put a long screwdriver on the tensioner bolt and feel the vibration. I don't recall exactly when it first happened but I remember the first thing I did was replace the tensioner as it had around 180K or something at that time so figured it was worn out and time for a new one. I was shocked when a new genuine Honda tensioner it didn't fix it. Since it only happened with the AC on I then figured it must be some extra vibration caused by an aging AC compressor and I wasn't going to bother with it. However, at around 203K the AC quit working.

I found a leak in the condenser and decided that with such high mileage it was time to rebuild the AC system. I replaced the AC compressor, condenser, and both expansion valves. When that was all done, the AC worked great (and still does) but that same vibration and rattle sound was still there when cold. While a visual inspection of the harnonic balancer showed no issues I decided to replace the harmonic balancer anyway since I was placing an order from Bernardi for some other parts. They are prone to failure on these engines and with the 218K that is currently on it thought maybe it wasn't lined up or somehow was causing the issue. I installed that last week. Nope. Didn't fix it.

After scouring the Internet and finding nothing at all about vibrations/rattles on the belt drive attributed to anything other than a bad tensioner I decided the only thing left was the belt itself. I'd replaced it at timing belt time at around 180K with a Bando belt but it had been making that noise prior. I don't recall what belt was on it before--probably a Dayco from Advance Auto. I've since learned Dayco belts aren't very good so I went with the Bando that time. I've installed many of them over the last couple of years and never had any issues or come backs with them. However, being at my wits end with this I decided to run to the local Honda dealer and buy a genuine Honda belt (supposedly made by Mitsuboshi.) When I brought it home and compared it to my Bando belt that still looked fairly new I was shocked. I've never compared two new (or lightly worn) belts before. I've compared a new Bando with a worn OEM and never noticed too much issue. However, below is what I found.

The Bando belt isn't that old and still has lots of life in it as is apparent by the the labeling still looking fresh. My special tool for measuring the grooves (not shown) showed it to be in great shape with very little wear on the groove side. Using a caliper I measured the thickness of both belts:

Bando: 4.38mm

View attachment 153589


Honda belt: 5.09mm

View attachment 153590


As shown above, the Bando belt is nearly 0.7mm thinner than the OEM Honda belt. That's nearly 20% thinner than the OEM belt. When you hold both at the same time there is a huge difference in the feel of the belts. The Honda belt is thick and rigid while the Bando belt felt thin and wimpy.

I installed the Honda belt and started it up. No more vibrations! I thought, well, I need to do a cold start so I waited until this morning and started it up again. Noise is gone.

Lesson learned: I've heard good things about Bando belts and have never had any issue with them. Their
As to why the thinner belt caused the tensioner to vibrate, I'm not sure. All I can think of is it tends to slap around a bit more than the thicker, heavier belt. It does go directly from the AC compressor to the tensioner so maybe there is a weird vibration there that causes the belt to slap a bit and vibrate the tensioner. For now I'm not able to duplicate the vibration and rattle anymore when cold so I'm happy. Just thought I'd share with everyone else since I've found nothing about anything like this anywhere on the Internet.

Wow this is amazing! I bet your happy as hell to have figured this out. I've been down the same road also and have even replaced things along the way. I have a continental belt on right now and it was really good for the first year but, now I'm back to having vibrations and belt squeal. I will have to see if replacing the belt with OEM like you did will help my situation. It was going to be my last resort as well.

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While I never had issues with cold rattle, like John's case here, I was intrigued by his finding. I typically buy Mitsuboshi 6pk2135 serpentine belt and have been more than happy with their performance over multiple timing belt jobs. I just happened to have one on hand and I did measure it as well. Mind you, if you go to Honda parts site, it will say that belt manufacturer is Mitsuboshi. So a Mitsuboshi belt I have on hand is about 4.5mm thick. While at the dealer this morning, I asked to compare original Honda belt for 2010 Odyssey to my Mitsuboshi belt. I also measured it and found it identical to John's finding. It was roughly 5.5 mm thick.

There are multiple conclusions that come to mind here. Just because two parts are made by same manufacturer, it does not mean the specs will be the same is the most important conclusion I come up with.

 

So I replaced the tensioner assembly on my 08 Honda odyssey because the belt was rubbing in the tensioner pulley and the mounting pulley of the assembly. Yet when I installed the belt the belt just slid on all the pulleys without me having to push in the tension pulley. Cant figure out what I need to adjust or replace. Any information would be greatly appreciated

 

you likely routed it wrong, compare routing with this pic

 

Do you have an LX, EX, EX-L, or Touring? The EX-L and Touring use a tensioner with a hydraulic piston for keeping tension. The LX and EX use a mechanical spring inside the tensioner. If the belt is routed properly then you should check the tensioner itself and make sure all the bolts are in the tensioner assembly. If it's the mechanical tensioner then there is a small bolt on the bottom of it that helps hold it in place. If it's the hydraulic style then you need to make sure the bolt is in the hydraulic cylinder and the hydraulic cylinder is good.

 

I have an EX. Here's the thing. I replaced the tensioner , routed the belt correctly and the belt is still rubbing. When I installed the belt after replacing the tensioner, I didnt have to push the tensioner to get the belt on. That leads me to believe that t may not be the tensioner but another part associated with the belt??

 

I would check your installation of the tensioner. Also, I'd check to make sure you have the proper belt.

 

Wow what luck this post resurfaced today.

I think I may have the same issue with rattling when cold and in gear (not sure if AC compressor kicking on since winter though) which I think started this summer sometime after having a shop replace my failed alternator and at the same time replaced the serpentine belt.

I was checking my oil level today and just happened to notice the belt was Bando. I saw this thread tonight and now I may have the answer. Thanks @John Clark !

 

I would like to add my story on this thread as it solved the exact problem on my 2010 Odyssey. I'm a ASE mechanic and have no problem saying I needed help solving this problem.

My issue started in December 2018, after I finished a complete timing job to include Aisin timing component kit, Honda side engine mount, NGK plugs and a BANDO sepentine belt. Engine ran nice and smooth, no codes etc afterwards but I did recognize a rattle noise of sorts when the vehicle was placed in gear. I double checked all installed mechanicals, focused on the plastic shields that I had removed, going as far as removing 1 at a time and driving for a period of days to try to isolate noise. Months go by and every morning when my wife starts the car and backs out of garage the rattle noise just drove me bananas.

Finally, a few weeks ago, I reached out to this forum for help. Opinions generally focused around the timing belt tensioner causing the rattle. This perplexed me as this was a part time rattle with specific conditions, when the car was cold, in gear and at idle rpm. I reasoned a faulty hydraulic tensioner would present whether the car was in park or in gear. A gentleman named BertS was the first to chime in with a alternative, referring me to this discussion and asking if I installed a Bando serpentine belt. I looked through my parts receipts, and sure enough a Bando belt. I read through this discussion and everything John Clark described fit my situation. I decided that even though this noise did not present as a serpentine belt issue, I was going to remove the Bando belt and reinstall the old Honda belt that I removed in 2018 since I had kept it and it wouldnt cost me anything. Wasn't too hopeful. I removed the 14000 mile Bando belt and compared the thickness to the 40000 mile Honda belt as John did. Sure enough, the Bando belt measured .018" thinner than the Honda belt.

I installed the old Honda belt and the noise completely disappeared. Its been over a week since and engine completely silent. Morals of the story: 1.Your never too old to learn new things 2. Ask for help if you need it. 3. Honda 3.5 engine needs Honda serpentine belt.

 

I would like to add my story on this thread as it solved the exact problem on my 2010 Odyssey. I'm a ASE mechanic and have no problem saying I needed help solving this problem.

My issue started in December 2018, after I finished a complete timing job to include Aisin timing component kit, Honda side engine mount, NGK plugs and a BANDO sepentine belt. Engine ran nice and smooth, no codes etc afterwards but I did recognize a rattle noise of sorts when the vehicle was placed in gear. I double checked all installed mechanicals, focused on the plastic shields that I had removed, going as far as removing 1 at a time and driving for a period of days to try to isolate noise. Months go by and every morning when my wife starts the car and backs out of garage the rattle noise just drove me bananas.

Finally, a few weeks ago, I reached out to this forum for help. Opinions generally focused around the timing belt tensioner causing the rattle. This perplexed me as this was a part time rattle with specific conditions, when the car was cold, in gear and at idle rpm. I reasoned a faulty hydraulic tensioner would present whether the car was in park or in gear. A gentleman named BertS was the first to chime in with a alternative, referring me to this discussion and asking if I installed a Bando serpentine belt. I looked through my parts receipts, and sure enough a Bando belt. I read through this discussion and everything John Clark described fit my situation. I decided that even though this noise did not present as a serpentine belt issue, I was going to remove the Bando belt and reinstall the old Honda belt that I removed in 2018 since I had kept it and it wouldnt cost me anything. Wasn't too hopeful. I removed the 14000 mile Bando belt and compared the thickness to the 40000 mile Honda belt as John did. Sure enough, the Bando belt measured .018" thinner than the Honda belt.

I installed the old Honda belt and the noise completely disappeared. Its been over a week since and engine completely silent. Morals of the story: 1.Your never too old to learn new things 2. Ask for help if you need it. 3. Honda 3.5 engine needs Honda serpentine belt.

Thanks for the post. I'm surprised you made it here. Most professional mechanics shun Internet forums, because on the forums many people often lack experience and post on things they know nothing about. It's nice to have some info from professional mechanics who do this every day. Second, you guys often get your info from Identifix and other professional forums/databases. I'd be curious to know if there is anything regarding this issue on any of those sites. I only wish I had access to those sites but they are limited to professional shop people only. I am semi-professional where I do work for others on my days off from my regular job but have no ASE's or affiliation with a professional shop that would allow me access to those sites and info.

When you share knowledge, you gain knowledge. That's just how it works. One of the pros I watch on YouTube states that on many of his videos. Many professional mechanics forget this and don't ever want to jump on a forum like this. There are things to be learned by all of us and we all benefit when sharing the knowledge.

Thanks again!

 

I wonder if many ASE mechanics know about the VCM issues and the benefits of muzzling VCM?