A Honda tech friend of mine traced the supplier back to Gates. It's important to note that oem suppliers change throughout the years. Bando was most likely a supplier at one point too! I can confidently say Mitsuboshi is NOT an oem due to the noise it makes when installed and the fact that the stitching, and rib patterns are different

 

Also the above applies only for the timing belt itself. The other components in the AISIN kit were identical to OEM. The koyo idlers, tensioner, and water pump itself look well built. They're performing great too!

 

And to drive the last nail in the coffin. Acura itself lists the manufacturer with the part number as Unitta. And who is Unitta you ask? Well none other than Gates co!! See image below

 

Just doing a drive-by of this thread to say that I'm suspecting the Aisin kit I installed (on my Accord...same engine though) as being problematic. At idle you can hear a pretty decent intermittent rattle that sounds strongest from the passenger wheel area right where the frame rail is and where the timing components are. Something like someone tapping their fingers on a cookie sheet pan every second...like a thin metallic rattle. You can't hear it in the cabin and with the hood open the general engine noise drowns it out, but standing to the side it's noticeable. So I'm going to just bite the $700 bullet and do all genuine...including replacing the crank pulley, timing belt guide, water pump, etc. It's basically a parts cannon but I'd rather spend $200 extra bucks and just do everything in the area than have to take it apart a third time if it isn't fixed.

TBH when I get under the car with the engine running it sounds like it's coming from the crank pulley so I'm really hoping I didn't undertighten that bolt or something but I did tighten to 250 ft-lbs for sure.

 

@dr/owned it wouldn't happen to be sound would it?

 

The cadence is similar but the tone is different because that video has the camera so close and everything is uncovered vs. me putting my head further away at the wheel and I have the timing covers and serpentine belt on. I've looked everywhere else on the engine, made sure it wasn't the catalytic heat shields rattling, put the screwdriver to my ear on the PS pump, intake,etc and the only place it sounds noticeable is with my head under the crank pulley near the oil pan or next to the frame rail.

And I just went to check again and there's no noise with a room temp engine.

 

From what you're describing, I'm pretty sure it's the same issue. I've installed hundreds of these Aisin kits and that sound is always there at idle. If anyone else is reading this thread for advice: Aisin kit is not oem, Aisin is not oem, AISIN IS NOT OEM!! I would start cheap and just replace the belt with a gates/unitta one and go from there. The source of the sound is from the tensioner being loaded and unloaded at every revolution. Probably due to the fact that the timing belt itself is a different size

 

How much cheaper are these Aisin kits or Gates belts that you guys are buying them instead of just buying everything from a dealer?

Like a $100-200 difference?

Kinda just seems worthwhile to buy from a dealer

Just because Gates Japan (Unitta) is the OEM supplier doesn't magically mean a Gates belt is the "same but without a Honda bag".

That's a bold assumption. Nobody has any proof whenever they say this, BTW. So...if you believe it, its purely out of convenience to save a few dollars.

None of these suppliers have to meet Honda's specs if they're not selling the parts to a Honda dealer.

They can make the part however they want. Why else would it cost less?

That being said....glad the OP and others stuck with it to find a solution to the problem!

 

I paid about $190 for the Aisin kit in 2019 but I think it's MSRP like $250 now and totally out of stock everywhere. The OEM shebang costs about $550 where the timing belt alone is $75. So in a sense it's worth "rolling the dice" if you're not paying for labor. Dealership labor to do the job is around $500. It's also unsure if whatever sound I'm hearing ever matters but I hear it so I have to OCD it.

 

I just want to chime in that this can happen on OEM components also, but with a failed hydraulic tensioner. Here is a video, documented by a guy at odyclub.com for 3rd gen Honda Odyssey.

 

Yes, I have the Aisin timing belt kit.. and the same sound. I am 57K miles in to the timing below.


@Kingcredible

So you are saying this will not negatively affect anything?

 

You've driven 57k miles on it already, I'd say you're good. The issue is mostly acoustic. That said, next one I install is going to be OEM. That sound is annoying.

 

So in a rather anticlimactic fashion I tore everything down from the Aisin kit to put in all OEM stuff. And I find that the upper pulley on the serp tensioner was free wheeling (meaning no grease left in it) and had some side-side play on it. Funny enough the first time I did this job I replaced the lower pulley on the tensioner but I didn't do the upper. It's plausible that could have been the noise but I already had so much stuff torn down that I just kept going with the timing belt replacement and didn't bother doing an A/B diagnosis.

Pro tip: just replace both tensioner pulleys when doing the timing belt. Upper is the left hand thread you wrench on to remove the serpentine belt. I'm going to be expeditious and try replacing just the bearing in the pulley since it's a "standard" 6203 sealed bearing that I can get in one day:

31180-RCA-A02 (upper)
31190-RCA-A02 (lower)


Also while I'm here it looks like the Aisin pump is closer matched to the original 2012 (ICD or ICO branded pump) impeller design than the 2021 Yamada impeller. I don't know if it matters. However the Aisin pump lacks a machined boss that the tensioning pulley bolts to that both the original and Yamada pumps have machined.

 

Is KOYO the best brand to be using for tensioners? I have both brand new KOYO ones installed and having the same noise problems w/bearing. My mechanic, who used to work for Acura dealership, thinks it may be from old stock parts sitting in a warehouse for awhile and it effected the grease. Thoughts on "break in" time for new ones? Will the noise eventually go away once theyre in-use for awhile? I have approx 100 miles on the new set making noise.