I have a 2004 Acura TL. It currently has 44,000 miles on it. I know the timing belt service interval is 105K / 7 years.

My question is about the 7 year limit? How hard and fast is that? The car has lived most of it's life parked in the garage. Texas does see it's fair share of 100 degree days, but not too many below freezing.

Preparing to change in June on the 7th anniversary of the purchase, but just wanted to hear other's thoughts.

 

IMO, the time limit is just as important as the mileage limit. I'm sure a mild climate and keeping it in the garage helps with the time limit just like freeway driving can extend the mileage limit over city driving, but you still don't want to push your luck.

 

I would think (and could be wrong) that if in a drier climate, the rubber would be expected to not last as long. If there is a time limit on the belt, the safest bet would be to change it. Yes, it's an expense, but if you have 44K miles on it and change the belt, you're good for another 7 years and 105K miles.

 

Yeap I planning to do my timing belt too but also the water pump. So I can be safe
The dealer has timing belt kit with everything for about $500 without labor but I have a private mechanic to do it for about 150 for everything.

 

To my knowledge, there is no published mileage or time limit for the timing belt interval for 3G TLs. It's all based on the MID messages, in this case a "4" (Reference your owner's manual, pg 199). My car is over 7 years old at 104,400 and I still have yet to get a MID message for the timing belt.

Have you seen the complete timing belt kit special for $295 offered by one of the Azine vendors?

https://acurazine.com/forums/3g-tl-2004-2008-93/complete-timing-belt-kit-special-%24295-763445/

 

I wouldn't base the belt's life on dry weather...its really mileage more than anything, under normal operating conditions. Weather has little affect on the belt. No matter what the weather's like, while the motor is running, the belt is exposed to that environment, and that's its normal environment.
It is also protected and unless you have oil leaks through the cam gear, crank, or coolant through the water pump, there's nothing else to get to it. It is sealed up pretty good, even moisture can't get to it.

That's a hell of a mechanic...$150 is crazy cheap. Goodluck though

The belt's life is based on mileage. That's how the MID gets the info, mileage. Your MID message may never display a message about changing the belt, but I wouldn't sleep on that. I wouldn't wait for the message if your car has 104k already...at 104k the belt has experiences some pretty heavy work, and needs to change. Don't treat it like a honda recommendation because they wanna make money. I don't agree on using their oil just because they recommend, but a timing belt is a different story. I suggest you get to it

 

Do you have any inside/published info from Acura that can/will confirm this?

 

I would bet that it's based on total engine revolutions.

 

That would explain mileage interval differences.

For example, say the car has only seen freeway mileage. The engine turns 1,729 revolutions per mile (assuming the gear ratios for the 5at I found are correct)

If it's only seen city stop and go and say the average gear is second gear. It spins 5,706 revs per mile in second gear.

In this sense mileage is irrelevent, engine revolutions are what count and you can see how there can be a HUGE discrepency on either extreme.

 

A little off topic but the 6mt spins 2,104 revs per mile vs the 5at's 1,729. You would probably never see the difference but I wonder what the average mileage is for MID to come on for the 6mt vs 5at.

 

No I don't. I just happen to know how your car works!

There's no sensors monitoring timing belt. The ECM calculates its life based on engine revolutions. Belt should be changed at 60K if car is regularly driven in weather above 110 degrees, or below -20 degrees. A you can see, MID doesn't know weather either, nor it knows time.

If you regularly change your oil every 3 months (for arguments sake), that would equal to about somewhat of a similar mileage intervals. So if you change your oil today, and don't drive your car for 2 months, then drive it for a month, you think your MID will say "oil life 15%" ? I doubt that.

See, the MID is not as smart as you might think. It simply provides preset info based on engine operating conditions (load etc) and accumulated RPM calculated by the ECM. Everything else displayed is preset at recommended intervals. It doesn't know when your air filter is really dirty either, this is why there's recommendations to change it earlier if you drive through dusty environments. Apparently the MID can't measure filter dust levels.

It's called "Maintenance Minder" for a reason...it simply reminds you, nothing else. Everything's already preset, and if you don't even follow the MID, reading your manual should easily provide you with service/maintenance recommendations.

 

I see IHC already cleared it

To add to my post:
Mileage reference is used because, it is what translates engine RPM to a more understandable and real life interval. So you say, you change your oil at 3000 miles, and not at, say "200,333,444" engine revolutions. Engine revs aren't always the same either. Engine reving at 5k with 60% load, and 2.5k 30% load isn't the same. So that is also taken into consideration and calculated. You can think of it as if you're always driving your car past 6k, the oil life wouldn't be the same, as if you drove normal and below 3k

 

Exactly. We know the usual parameters of the MID for an oil change. The ones I know for sure are engine revolutions, cold starts, average load, average time of trip, ambient startup temp, and I'm sure there are ton of other ones. What I was told by an insider is the biggest influence is number of cold starts vs average drive time. Apparently this affects the interval more than anything else. Seems to be true because mine signals a change at 3,500miles now that I drive a total of 5 miles a day. When I did freeway driving even in the winter, it would go to nearly 10,000 miles.

 

Yeah, this is what I wonder also. It would seem the old 7 year interval can be discarded since I'm past 7 years. The MID does monitor several parameters besides mileage. Who's to say that Acura didn't program it to incorporate some of these additional parameters when calculating timing belt intervals?

I do drive mostly highway miles and the MID indication for when an oil change is due for me has consistently been 7500 miles. It's going to be interesting to see how this plays out on my car. Not sure if this is an additional factor, but I'm now at 30% oil life, meaning I'll have an oil change due in about 2300 miles (106,700). I'm halfway expecting the "4" to show up along with the "A" or "B" at 15% oil life.

Not that it makes a huge difference, but there is also the fact that our odometer (2992-2006 year models) is off by 5% (reads high). At 100K, that's 5000 miles....

Ah yes, but HOW do you KNOW this??


Not entirely true. For normal conditions, there is no published interval other than MID indication for:

Transmission fluid
Oil/Oil Fliter
Spark Plug
Timing Belt
Rotate Tires
Air filter
Cabin air filter
Engine Coolant

 

I forgot to put the totals not that it's hard.

So a purely freeway driven TL at 105,000 miles, the engine has spun 181,545,000 revolutions.

A purely city driven TL has spun around 599,130,000 revolutions.

Of course there will never be a purely highway miles TL or purely city miles TL but it makes my point. Obviously it does not take into account revs while sitting still in neutral.

The only mechanical factors on the timing belt would be total revolutions and rpms. Engine load has no influence. High rpm puts a little more load on the belt but it's probably insignificant in the grand scheme of things.

This is disregarding climate. Mine has seen a 100+ degree summer evey year since I bought it new. I may hurry up and change mine.

 

No one is saying, it doesn't calculate timing belt life, but it isn't calculated any other way other than engine revolutions, because nothing else has a sufficient impact on it's life under normal conditions.

All those things are published on the MID indication in your book, no? That is the publication...Look at symbol B...it states to inspect the whole damn car.
the Sub items in numbers.
Air filter at 15k, if driven in urban areas. same for cabin filter, and whenever air flow decreases (how smart)

Spark plugs, timing belt, are part of the Tune up interval at 105k. Engine coolant at 5 years. Tranny fluid at 60k then every 30k. Rotate your tires after every 2nd oil change.
Also, take a look at the manual, and look at the pattern of the maintenance item descriptions, along with their symbols.

Have you been paying attention how the symbols appeared over time?
I'd like to know how many times you've gotten "A" displayed.

Also, take a look at the manual, and look at the pattern of the maintenance item descriptions, along with their symbols.

If you notice, the items for which the MID can't really calculate, it clearly states when to change, based on certain conditions, such as the filters, or tranny fluid.

All I've been trying to say to you is, it really only truly calculates engine oil life. Everything else is a preset Scheduled Maintenance.

 

Again, that's for abnormal conditions, for normal conditions the interval is determined by the MID...

You must be looking at a different owner's manual than mine. Nowhere can I find where it says:

105K for timing belt/spark plugs
Engine coolant at 5 years
Tranny fluid at 60K and then every 30K (only applies to slow speed mountainous driving). For normal driving, there is nothing listed except for the MID indication of "5".

Again, no it does not. Not for normal driving. Normal driving intervals for filters and tranny fluid are soley determined by MID indication.

 

They are not determined by the MID, they are spoon fed to you by the MID!
Again, they are SCHEDULED MAINTENANCE services... SCHEDULED


Your engine oil is the only thing that's not scheduled. It is actually calculated based on certain parameters.
This is the big point you're missing.

Either way, you win.
I'm off this discussion.

 

I think the best way to say it is the MID hand feeds you the maintenence reminder at the scheduled engine mileage lol.

So you can say it does not calculate but instead just reminds you at a scheduled engine mileage...

That's as politically correct as I know how to be.