My 2010 EX-L Odyssey with 128,000 miles on it is making a "clanking, rattling" sound when I first start the engine when it is cold. It lasts for about 15 seconds and then completely goes away until the next cold start. It does this while in park and I assume the AC compressor is running, as it usually is always turned on. It's been doing this for a few months. It has an aftermarket Continental belt installed that is fairly new. I had the belt and the hydraulic tensioner replaced in January 2018 when I had the timing belt job done at 100,000 miles. The new tensioner was a genuine Honda part.

Knowing about this thread, I already bought a genuine Honda belt from Majestic for $38 plus shipping. I am hoping when the new Honda belt is installed this noise goes away. I will certainly report back on that here.

My question now for John is this: Did your noise sound like a clanking/rattling sound? Those are the best words that come to mind to describe what I am hearing. It almost sounds like a heat shield rattle sound to me, but I know that is not it. I am not savvy enough to post a YouTube link to record the sound and it does not last long enough for me to use a stethoscope to better isolate the source.

Thank you.

 

It was a lower pitched rattle sound. I could take a long screwdriver and put it on the bolt while the engine was running and feel it at the tensioner.

It is also common to have some of the heat shields rattle underneath the car so that should also be checked.

 

I’ll definitely check my heat shields. I installed band clamps around the ones at the converters a couple years ago. I know there are others to check. I wouldn’t think a heat shield rattle would go away in 15 seconds unless there’s some sort of thermal expansion going on.

 

Sometimes it seems like it's related to the engine being cold when it's really just related to the RPM of a cold engine. This is what I found with the serpentine belt tensioner rattle. It only happened when cold, with the AC on, and in Reverse or Drive at idle. When it warmed up it went away. However, when I got more into it, I found I could make it happen any time if I was able to put it in gear and get the RPM just right at 11-1200 RPM, the same as where it idles when cold.

 

John:

I figured out how to upload a video to YouTube of the noise I am hearing. I hope this link works. Note that this is a cold start. The AC is off. Noise goes away after 30 seconds. Does this sound like the tensioner and belt issue you experienced? If not any guess at what it might be? Thank you very much.

 

It does sound similar. Try removing the serpentine belt and see if the noise goes away.

 

Update:
I finally had the genuine Honda serpentine belt installed in hopes that it would resolve my cold start clanking/rattling noise issue. Sadly, it did not.

 

Did you remove the belt first and run it to see if the noise was still present, as I suggested?

 

I did not. I had the Honda belt installed by my independent mechanic in conjunction with some other work I was having done.

 

It's an important step (at no cost) to determining the location of the noise.

 

Follow-up: I just had my exhaust J pipe (aka Y pipe) replaced due to a leak. I no longer hear the noise upon cold engine start. I need to get more data samples, but I’m hoping this issue is resolved. Could just be a coincidence, however.

 

Recently replaced a belt, and tensioner kit. After replacement, nothing but issues. Last issue presented is harmonic balancer knocking. Going to try the OEM Honda belt and see if this resolves the problem. If so, this needs to be more widely addressed by Honda. I have never had such issues with a simple job like this one. This would be the first vehicle I have worked on that has been so specific to what belt it likes.

 

Keep us posted.

 

John Clark and others, thanks for this post! I have a 2008 Odyssey Touring with 143,000 miles. My wife told me it was "making a funny noise". It sounded a little like marbles in a tin can. I suspected the AC clutch or tensioner after noticing the noise would go away when the AC compressor would turn off. After some confusion between the two types of tensioners (spring vs hydraulic - mine is hydraulic of course), I found this post and checked the belt itself. I thought it was good as it was replaced around 100k when they did the timing belt, but I did notice it had a nick in it. I figured I'd replace it either way and see if that takes care of the noise. Additionally, the belt they used was a cheap "Bando" brand, but I sprung for the $30 Continental belt at AutoZone. Also picked up the belt tool with the extension and I'm glad I did.

I also wanted to note, the Continental belt seemed so much thicker and robust than the Bando. Maybe the thinner belt stretched too much? Also, the tensioner, pulley, idler pulley, and harmonic balancer all seemed good. The noise seems to have gone away so far. We'll keep an ear out for it, though.

Just some notes for folks that want to replace the belt, I found it was difficult to get the belt back on with just the tool itself. And I'm a relatively strong, big guy. I put the extension on it with a 1/2" 19mm socket (FYI, this does not come with it, you have to have it or buy a 19mm socket), angled against the alternator wire loom and then the handle attaches to that with it's 3/8" end - push towards firewall. This gave me the extra leverage that made sliding the belt on the tensioner pulley much easier. I did everything from the top of the engine, removed the engine cover, unlocked the power steering reservoir from it's bracket and put the prop rod in the second location towards to the back of the hood to provide more room. It was a little difficult routing then new belt through the idler, AC and crank pulleys, but I got it without too much trouble.

Anyway, appreciate the info from this site, it helped save me quite a bit of time and money.

 

Welcome to this forum; I'm glad it helped you resolve your issue. FWIW, I do not know if the new Continental belt you installed is as thick as, and as good as, the genuine Honda belt. For a little bit more money, you could have bought the Honda belt. If your noise returns, that's what I would recommend you do.

Have you muzzled your VCM? Timing belt been changed?

 

Also, to note, the hydraulic tensioners require a somewhat special procedure for releasing tension. You are only supposed to apply steady pressure and allow the hydraulic piston to move slowly. If you force it hard, as you would with a spring, with a lot of leverage, you can damage the hydraulic piston assembly.

 

thscott, thank you. I'm not sure about the thickness vs Honda's belts, but it was noticeably thicker than that Bando belt. It also has a 3 year warranty, so it appears to be a quality part. As you said, if the noise develops again, I can order a Honda belt and try that. And nope, we have not muzzled the VCM and the timing belt was changed around 100k. One odd thing I should mention: the valve covers developed holes in them around some of the spark plugs - looked like some kind of weird corrosion. Had to buy new valve covers and the VCM was leaking badly, got that replaced as well. Both of these happened around 130,000 miles.

John Clark, gotcha, yes, slow steady pressure took care of it. There may be a dozen ways to do this, but for the way I was doing it, putting the extension on the belt tool moved the handle enough to avoid pushing into the power steering reservoir hose and provided a little more leverage. I may not have been able to get full lockout on the tensioner due to that hose being in the way.

 

Read up on VCM; most peope here disable the function with an inexpensive device. VCM can cause all sorts of serious engine issues. There's no reason not to disable it.

 

Will do, thanks for the heads up. And FYI, it was the VVT solenoid gasket that needed replacing. Not the VCM

 

Well, this report shook me up! Hope my 2014 odyssey J35Z8 - VCM doesn't develop the same problem. Just in case, I've bought 4 belts today,for real, from different companies, to test them in the near future. Bando, Mitsuboshi, Continental, & Gates. (I don't use Honda parts, since, if the cars are no longer quality, then how can their expensive dealer parts be quality? Thank you for reporting this.

 

Well, this report shook me up! Hope my 2014 odyssey J35Z8 - VCM doesn't develop the same problem. Just in case, I've bought 4 belts today,for real, from different companies, to test them in the near future. Bando, Mitsuboshi, Continental, & Gates. (I don't use Honda parts, since, if the cars are no longer quality, then how can their expensive dealer aprts be quality? Thank you for reporting this.

??
You bought 4 aftermarket belts knowing from this thread that only Genuine Honda belt will work well?
I look forward to the results of your research project.

 

nice catch!

 

My apologies for being a doubtin' thomas. i believe they solved this problem in the 2011-2017 series, but maybe not. i'm now a convert. i've now found similar problems on other car forums. kudos to john clark

 

ashirm98 would you mind to update? thanks

 

Same problem drove me crazy for a year. John Clark still helping out in 2023.

 

i just want to thanks the author, i'm from Brazil and i have an honda City 2010 1.5L L15A engine (basically the sedan version from fit ge8), and i've went crazy for about a year with engine noises, on last weekend i've notice that the belt tensioner was vibrating, so i thought that it was the problem, and i went for google and i spawned on this post, i was using an dayco belt.. since other guy where on post said that continental belt has about same measures from the OEM, so i ordered from internet the belt from continental, few days later it arrived and i've installed it.. and voy ala... engine running like new again with no abnormal noises

 

Good going. FYI, John Clark is legendary here in the USA, and now perhaps in Brazil.

 

Add me to the list of cold-start-rattle-fixed-by-Honda-belt. I used a Bando serpentine belt during a timing belt install and thought I messed something up for the longest time. New belt, no more rattle. Thanks John.