Time Based Scheduled Maintenance - Legit?

Status
Not open for further replies.
Joined
Dec 2, 2005
Messages
1,465
Location
Kennett Square, PA
Which traditional time based scheduled maintenance items are valid? I ask because my 1999 Toyota OM says time intervals are based on the assumption that people drive 15k miles per year. E.g., Toyota says replace coolant every 24 mos or 30k miles. Surely coolant does not significantly degrade in a sitting car. I now believe Honda makes the same assumption. Honda used to specify 7yrs/105k miles for timing belt. When the MM was introduced, Honda no longer specifies time based maintenance except to replace brake fluid every 3 years. Since the MM does not count time, Honda owners do not get a MM prompt to change TB until 105k miles. I believe Honda carefully reviewed their scheduled maintenance when they introduced the MM and concluded the only necessary time driven item is brake fluid. If Honda engineers thought TB's needed to be replaced at 7 years independent of mileage, they would have added that footnote. After all, a broken timing belt does far more damage than 3 year old brake fluid. Acura/Honda dealers still recommend 7yrs/105k miles which I believe is driven only by profits.

So, what scheduled maintenance items are truly required based on time, independent of mileage? Thanks.
 
I think most of it is vehicle specific. A car that sees few miles here in NY may be different than a car that sees few miles in the AZ desert.

As for timing belt interval on Hondas, I think they are extremely conservative. There's a lot of people that never change it.
 
Brake fluid and coolant are the only ones I truly follow on a time basis. Elastomers (eg. in timing belts) do break down over time, but that amount is so insignificant relative to the wear those parts get from mechanical usage (mileage). Unless we are talking decades apart between intervals, the 7 year suggestion is just an extremely conservative estimate.

Lubricants like oils should effectively last forever sitting around. The acids in oils would be my concern, but unless you are storing the car for years, the additives in oil should keep those nasties suspended.
 
I just had a timing belt losing teeths after 9.5 years and 90000kmeters on the Peugeot 206. Spec is 10 years or 120000kmeters. I'm left with a broken engine (will take apart another day, still got the Yaris). Will never think it's ok to do those replacements as close as possible to the limit.
 
Originally Posted By: Superflan
I just had a timing belt losing teeths after 9.5 years and 90000kmeters on the Peugeot 206. Spec is 10 years or 120000kmeters. I'm left with a broken engine (will take apart another day, still got the Yaris). Will never think it's ok to do those replacements as close as possible to the limit.


Do you know who made the belt? Are you sure the belt failed, ie is it possible a water pump or idler bearing seized causing the belt failure? I just removed a Mitsuboshi belt from my 99 Avalon at 9 years/50k miles. It looked absolutely brand new. Thanks for your response.
 
Last edited:
I mostly go by mileage. Yes, recently replaced a 10 year old timing belt with 97K miles on it that has lost 9 teeth. It was an inconvenience, and I will not let one go that long again (since on this car it was easy enough to replace).
 
I would think coolant would also be time based. The timing chains and serpentine belts on my 2 cars are 15-19 years old. Only plan to replace 1 of the 4 any time soon.
 
Originally Posted By: artbuc
Do you know who made the belt? Are you sure the belt failed, ie is it possible a water pump or idler bearing seized causing the belt failure?


no bearing or tensioner issue from what I can tell. When i said "losing teeth" I meant lot of them. The engine failure (interference) seems to be because on one section there is a lot of contiguous teeth missing (and some random others).

The belt failure seems from heat.
 
Let me pose the question in another way - my first attempt was not too hot. Let's say you were given a brand new 8 year old car (with timing belt, not chain) which had never been driven. It had been stored in a conditioned garage. What would you do to it before taking it out on the interstate for a long drive?
 
Last edited:
Originally Posted By: artbuc
Let me pose the question in another way - my first attempt was not too hot. Let's say you were given a brand new 8 year old car (with timing belt, not chain) which had never been driven. It had been stored in a conditioned garage. What would you do to it before taking it out on the interstate for a long drive?


I wouldn't even start the car before changing the belt... and make sure it had oil pressure etc before keeping the engine running.
 
Status
Not open for further replies.
Back
Top