racerock

The following information is thrown out based on my experience and yours may be different. It it based on:
- Replacing Timing Belts as part of regular maintenance on a number of different Honda and Acura vehicles with known history
- Replacing Timing Belts as part of maintenance on cars with unknown history
- Replacing Timing Belts as part of engine repair on various make cars after picking them up due to broken timing belt that required after correcting head and sometimes piston damage that resulted

1. Remove the inspection cover
2. Rotate the timing belt to see if you can see a series of numbers in typically three groups. They wear more with age
2a. If you don't see the markings, they have probably worn off, but if you use a bright LED flashlight at an angle while someone rotates, they can be seen. Might not be obvious, but they are there.

3 The belts typically have three groups of numbers. Honda uses:
a. A group of numbers that show the distance in the mfg run
b. A number that indicates the year of mfr
c. A number that indicates the week of the year it was manufactured

4. Aftermarket typically uses the year and week. It might have distance in a different manner

5. Then using the clues, you can ballpark the date of installation and get close to if:
- It is original (if you can see the year)
- It was installed after, recently or somewhere in between
- Note: If you bought the car, do not know the history and don't see a year - assume it is original...That would be my advice.

Recent pictures I took:

1. Brand new belt, picture taken at an Acura Dealer Parts counter showing:
Distance (130)
Year (5 = 2015)
Week (32)
2. Aisin Belt
3. Belt with 103K miles showing Honda Logo with LED flashlight
4. Belt with 103K miles showing a very (near impossible) hard to see date code

01acls

This is great trivia info but it's pretty much useless bc there is no direct correlation between manufacturer date to sales date and then to the actual installation date.

Also dates have zero correlation to mileage.

As the saying goes... "Assumption is the mother of all f'ups".

racerock

Exactly, which is why the title uses "Ballpark"
- It does help if you buy one with say 100K and you see a mfr date of this year. You would know it is not original and can ballpark the mileage using the worst case
- It does help if you buy one with the same 100K miles and you have to use a flashlight to see the markings - you would then ballpark the miles at 100K Miles

- Your point is exactly why I posted the pictures. See the belt I just bought this month and installed a few days ago? It was built a number of years ago. To be on the safe side and one did not see the sticker I put in the engine compartment, I would use sometime that year and then ballpark the annual miles from there based on the current miles.

Yes - ball park is the point. Not exact - unless you still have the original belt.

truonghthe

Honestly on all the car I ever owned every car passed 100k miles will get TB/WP service done UNLESS the previous owner has some kind of documentation to show or indicate in carfax the service has done. When come to risk either replace a new engine or $600-$800 for the service I would rather spend the service and knowing it good until 200k miles or more.

DogP

Can anyone confirm that TLs would have come factory with a Honda timing belt, and NOT Mitsuboshi? The guy I bought my 08 Type S from said the timing belt and water pump was changed a while back, but didn't have any documentation on it (and I didn't find the sticker placed anywhere). I'm at 150K now, pulled the top cover back, and found a Mitsuboshi belt that doesn't look new, but still has markings. Am I safe to assume that it has been done, at least at some point?

Thanks,
Pat

01acls

Honda/Acura uses various manufacturers for parts. It will not source just one manufacturer incase the manufacturer has production issues. Mitsuboshi was and may still be one of oe belt suppliers for Honda/Acura and other Japanese auto manufacturers.

I can tell you your belt is fairly new 50,000 miles is about right based on your pic.

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DogP

Cool... thanks! I'll plan to do the next one a bit early, but I wanted to make sure I wasn't at 9 yrs / 150k on the original.

Pat