Thanks,...me too! I am going to try to call a tech and Honda corporate.
Yamada water pumps
- Thread starter rcs
- Start date
On some Accords they recommended new water pumps but they don't say why. (Interestingly, the part for the 2007 accord points to an aisin water pump.... Not yamada). The faulty part according to the tsb is the mounting flange on the oil pump, not the water pump. You state that there is a shim to correct the angle of the idler pulley when using aisin water pumps, but the mounting boss for the idler pulley is on the oil pump.
I think what's more likely here is that the oil pump IS faulty, but it's cheaper to shim it than replace it.
As to why Aisin pumps are exacerbating the issue, your guess is as good as mine, but it also explains why some oem parted TB replacements have had this noise as well. You stated all oem parts don't have an issue, but I believe I've read threads that indicate otherwise.
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Hmmmm.....I have installed a dozen or so Aisin TKH-002 kits on the J series engines and have never had a problem. Must be lucky. I have one vehicle that just flipped 300k miles and I think I put the final belt and kit on it, however I also said the kit at 200k would be the last.
After much research and replacing the timing belts on four Honda J35 V-6 engines since 2018, I believe the warble is due to a slight mismatch in the angles of the idler pulley in relationship to the water pump drive pulley. Contingent on the temperature and flexibility/tension of the timing belt, the tolerances can change just enough to allow the outer edge to rub intermittently against the aluminum motor mount bracket. I suspect the angle of the Aisin water pump's pulley is off enough to exacerbate the noise compared to the Yamada pump.
Last October, I performed timing belt replacements on two Honda Odysseys using the Aisin kits (TKH-001 & TKH-002) along with the (ridiculously pricey) Honda taper shim. I fitted the unmodified aluminum motor mount bracket and could not slip an index card between it and the new timing belt's edge. As such, I removed the bracket and ground off the metal per the TSB to create a 3/32" air gap from the belt. As of today, neither vehicle chirps or warbles at all.
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This is really interesting, thank you for sharing. What year was the tkh-001 oddysey? I don't suppose you installed the tkh001 kit and ran it to see if there was noise before you installed the shim? Correct me if I'm wrong but it seems like as the geometry & individual piece variation within tolerance, either pump (aisin or yamada) could be problematic depending on the oil pump? What a mess.
The
The TKH-001 TB kit went into a 2003 Odyssey (EX-L) and the TKH-002 kit went in a 2006 Odyssey (Touring) w/VCM. I had also previously installed the Aisin TB kits on these vehicles in 2018 (approximately 110,000 miles earlier) w/o the taper shim and the 2006 had a minor intermittent chirping noise for ~4 months. I suspect the tolerances changed and/or the belt wore ever so slightly over that period. There was no discernible abrasion on the belt when I removed it in October 2023. While the 2003 Odyssey never chirped with the previous belt, I opted to install the shim and grind a relief groove in the motor mount as a pre-emptive measure.
The reason that I believe the root cause of the noise is the misaligned idler pulley (due to the imprecise casting of the oil pump's mounting boss) comes directly from Honda corporate. Our family has owned several Hondas since 1977 and over the years, it has become clear that Honda notoriously refuses to acknowledge engineering or quality shortcomings in their products. However, for this J35 warble issue, they not only issued an official TSB, they manufactured a new specialized limited application Honda part (i.e., taper shim) to "fix" the issue. By the way, the taper shim is essentially a 2" diameter fender washer that is thinner on the left side than on the right side. The MSRP on the taper washer is (are you sitting down?)...........$31. I also learned that the aftermarket timing belt/water pump kits sold by Gates Rubber and AC Delco contain a facsimile of the taper shim.
While the noise can appear with either the Aisin or Yamada water pump, the anecdotal reports suggest that it is much more prevalent with the Aisin pump. Likely due to slightly more pulley angle offset on the casting/assembly of the Aisin water pump.
The TKH-001 TB kit went into a 2003 Odyssey (EX-L) and the TKH-002 kit went in a 2006 Odyssey (Touring) w/VCM. I had also previously installed the Aisin TB kits on these vehicles in 2018 (approximately 110,000 miles earlier) w/o the taper shim and the 2006 had a minor intermittent chirping noise for ~4 months. I suspect the tolerances changed and/or the belt wore ever so slightly over that period. There was no discernible abrasion on the belt when I removed it in October 2023. While the 2003 Odyssey never chirped with the previous belt, I opted to install the shim and grind a relief groove in the motor mount as a pre-emptive measure.
The reason that I believe the root cause of the noise is the misaligned idler pulley (due to the imprecise casting of the oil pump's mounting boss) comes directly from Honda corporate. Our family has owned several Hondas since 1977 and over the years, it has become clear that Honda notoriously refuses to acknowledge engineering or quality shortcomings in their products. However, for this J35 warble issue, they not only issued an official TSB, they manufactured a new specialized limited application Honda part (i.e., taper shim) to "fix" the issue. By the way, the taper shim is essentially a 2" diameter fender washer that is thinner on the left side than on the right side. The MSRP on the taper washer is (are you sitting down?)...........$31. I also learned that the aftermarket timing belt/water pump kits sold by Gates Rubber and AC Delco contain a facsimile of the taper shim.
While the noise can appear with either the Aisin or Yamada water pump, the anecdotal reports suggest that it is much more prevalent with the Aisin pump. Likely due to slightly more pulley angle offset on the casting/assembly of the Aisin water pump.
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One thing that I'll add here is that the 04 and earlier J35a4 has a different part number for all of the timing components, including the oil pump. I realize there are a handful of noise complaints with earlier engines, but the vast majority seem to show up with the 2005 pumps.
That makes sense since the TSB applies to the 2005 MY forward.
Thought I would share this, the area that the tsb has you relieve on the 05 and up with a sanding disc is relieved as part of the cast in the 04. Interesting.
I also noted that a very shallow (~2 mm deep) and faint relief area in the 2003 Odyssey's motor mount but none in the 2006 Odyssey's motor mount. I ended up removing metal from a larger surface area than the relief outline shown in your photo until only 2 mm of metal remained on both motor mount brackets per the TSB's instructions.
I found examples of both style motor mount brackets for sale on eBay:
motor mount bracket (no relief) and mount bracket (w/shallow relief groove)
TSB instruction photo
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