2008 Civic LX AT Loud Rattle (Belt Tensioner???)

[gathermewool]

107k miles. I've had a rattle for the past 20k miles that has gotten worse, coming from the drive belt area on the passenger side of the engine. I thought it was due to the hydraulic mount being faulty, but that didn't fix the rattle (though it did fix the loud rumbling that occurred at first startup and over bumps or heavy braking - the mount was faulty.)

I replaced the drive belt when I swapped out the mount, because it was accessible, and like a bone head I forgot to check the tensioner. I did NOT notice any issues with the tensioner while compressing it to install the new belt, and the neither the new nor old belt squeals or has an issue with tension.

Now that the rumbling due to the mount is gone the rattle is much more prominent. The colder the startup temp, the louder the rattle. I bought a Lisle mechanics stethoscope to poke about with, and while the stethoscope can't be assembled completely, because the metal disc doesn't thread onto the metal rod, it worked well enough to hear a definite change in sound when I poked the tensioner, compared to the head, block, alternator bracket, hydraulic mount and bracket, etc.

With the sound now clear via the stethoscope, I could also see that the tensioner seemed to flex or move a small amount in time with the noise I heard. I know a good video would help, and I'll try to get one when I can, but I'm almost certain that the issue is the tensioner and not a heat shield (none rattle at all.)

TO THE QUESTION:

Online Majestic Honda Parts illustration number 17 has two part numbers for the bolt that fastens the tensioner to the block:

90001-R1A-A00 017 001 BOLT, SOCKET (10X59)

96700-10055-18 017 001 BOLT, SOCKET (10X55)

I contacted Majestic Honda and they said either would work. I mentioned that that doesn't make sense, but they insisted that even a VIN lookup showed both fasteners as being acceptable. The difference appears to be 4mm in length (~1/6")

Any ideas?

Also, with this exact bolt being a failure point in the 2006 Civic (causing massive damage or shearing off and having to be extracted while replacing it due to maintenance, IIRC) I'm thinking about letting someone else do this. Any suggestions?

 

[DuckRyder]

OK I'm going to admit to being a little confused about the question, but here goes.

RE: Isolating the noise - If you have a long screwdriver or extension, you can use that much like a stethoscope to isolate the noise. You can also remove the belt and feel for roughness in the bearing while turning pulley (25) it may be possible to replace only part 25.

RE: The bolt - I assume you have found the TSB/Recall on the 2006 bolt indicating that the cause of the issue was the factory over tightening the bolt? This should not be a concern with a 2008? The bolts are less than $3 for both, I'd probably just order both and replace the OE bolt with the new one that matched.

RE: Someone else fixing - If I was going to take it somewhere it would be the Honda Dealer. I'd be sure to tell them not to touch anything else unless I wanted them doing a lets see what we can sell him (Courtesy) inspection.

 

[gathermewool]

Originally Posted By: DuckRyder
OK I'm going to admit to being a little confused about the question, but here goes.

RE: Isolating the noise - If you have a long screwdriver or extension, you can use that much like a stethoscope to isolate the noise. You can also remove the belt and feel for roughness in the bearing while turning pulley (25) it may be possible to replace only part 25.

RE: The bolt - I assume you have found the TSB/Recall on the 2006 bolt indicating that the cause of the issue was the factory over tightening the bolt? This should not be a concern with a 2008? The bolts are less than $3 for both, I'd probably just order both and replace the OE bolt with the new one that matched.

RE: Someone else fixing - If I was going to take it somewhere it would be the Honda Dealer. I'd be sure to tell them not to touch anything else unless I wanted them doing a lets see what we can sell him (Courtesy) inspection.


Sorry for the confusion; I'll try to clarify:

One bolt attaches the accessory belt tensioner to the block. Why are there two part numbers that are both correct? It doesn't make sense to me. The difference doesn't appear to be material or vendor; one is 4mm longer. Why?

RE: screw driver:
I already have a stethoscope and have isolated the noise to the vicinity of the tensioner. I haven't had time to determine if it's the pulley or tensioner, however.

In my limited experience, pulleys usually squeal or grind. This is more like a deadened heat shield-type sound.

The area is tight, so even simply compressing the tensioner, removing the belt, and operating the pulley by hand is a major pain.

If it does turn out to be the pulley, I don't plan to pay what they want for the pulley - if you'll notice, the pulley costs more than the entire assembly! The pulley comes with the assembly, which costs less than $100.

I'd probably buy an AAP or Rockauto pulley for 1/4 the cost of OEM.

RE: someone else doing the work:
I've thought about this. I called the local dealer (who gets much praise by coworkers) parts guy, who said that he seen enough ordered to consider its failure common enough for him to keep it in stock, but not enough to think it's widespread.

I haven't gotten a quote, but he can't match online parts cost (his best quote was $120 + tax.) I don't know what book value is on this, but i'd guess a bill in excess of $300 when all is said and done. If they have issues with removal (e.g., mauled block threads, sheared bolt, etc.) I guess I'd be responsible for the additional cost, right?

If the issues meant more labor time, then higher dealer labor rates may cost a lot of money.

The bolt shearing may be specific to the '06 model year, but it's a concern and considered a possibility for worst-case, what could go wrong-type evaluation. If I do this myself in the hobby shop and the bolt shears or the block threads are mauled I might be screwed. The hobby shop is getting some good funding for tools lately, but they still don't have a good tap and die set, nor an easy-out, so I'd have to buy my own possibly.

Fingers crossed for it being the pulley.

 

[Merkava_4]

1. Buy both mounting bolts from the dealer and use whichever one matches the original best.

2. Buy the tensioner assembly from RockAuto. Done.

 

[gathermewool]

Originally Posted By: Merkava_4
1. Buy both mounting bolts from the dealer and use whichever one matches the original best.

2. Buy the tensioner assembly from RockAuto. Done.


Darnit, I forgot one key concern with buying both fasteners:

What if the bolt in there is wrong,and there is a reason for the difference in length?

If it's not just the pulley, then I'll probably buy both fasteners and see if the longest one works, and how many more turns there are before it bottoms out.

 

[Merkava_4]

Originally Posted By: gathermewool
What if the bolt in there is wrong,and there is a reason for the difference in length?


Try the longer bolt first. If it doesn't bottom out before getting tight, keep it.

 

[gathermewool]

Originally Posted By: Merkava_4
Originally Posted By: gathermewool
What if the bolt in there is wrong,and there is a reason for the difference in length?


Try the longer bolt first. If it doesn't bottom out before getting tight, keep it.


That's now my plan.