Low mileage can trump age when deciding on timing belt replacement

maintenance

#1

How fast do the odds of original timing belt failure increase, according to manfacturer’s statistics, after 8 years of aging under the following scenario?



1. 1999 Honda Civic driven about twice a week an average of 21 miles per trip (present mileage 17556)



2. As only owner (82 year old retiree) since purchased new I have had following preventitive maintenance done by dealer.

A. Oil and filter change every six months.

B. Coolant replaced every three years.

C. Transmission and brakes adjusted with fluids replaced, and air filter changed, once.



3. Only problems have been failure of a pollution control sensor and the fuel pump. The car still runs like a top! Use only medium grade gas from major oil companies.



4. Driving conditions not severe (entirely in Florida over paved roads in mild climate with no towing)



PS My husband thinks I am a cheapskate but I do not want to spend hundreds of his dollars unless historical data warrents it. The operating manual can only address the average situation which mine is not. Also leery of major maintenance because with previous car mechanic forgot to replace all the bolts.


#2

Bernadette, you’ve done a great job maintaining your car. You are entirely correct in stating that the factory recommndations have to address average use, and average time of deterioration.

If I was in your shoes I would seriously question the need for a timing belt as well; there are examples of Civic owners who drove 160,000 miles on the same belt; not that I would recommned that.

I think you should replace the belt in the next 2 years, so you can plan ahead. And go to a different mechanic, one who knows where all the bolts go. If you lived in Arizona, I would say replace the belt very soon.

Happy motoring!


#3

I’d replace it because of time. The rubber will still deteriorate, and could cause problems. This is an interference engine design, meaning that if the belt breaks, it will cause damage to the valves and pistons. This could mean THOUSANDS of dollars in repair costs to get it fixed right. Also, it is recommended that the water pump be replaced at the same time, since it is also driven by the timing belt.


#4

If that car has the original belt then you’re driving around with a time bomb. That belt may never break or it may break tomorrow; and the latter is going to cost you big time.
All of those maintenance items you mention and habits such as no towing and paved roads have zero, zilch, and nada to do with the timing belt.

Rubber items deteriorate, pure and simple, and a timing belt is no different. Look closely at an old tire and note the dry rot. The timng belt suffers the same thing.
I agree with your husband and it seems to me you’re taking a big gamble here by risking engine damage on a vehicle with a paltry 17k miles on it.


#5

I’d change the belt. It is a lot cheaper than a new engine. As far as a mechanic, try to find a shop that does Honda/Acura exclusively, or at least Japanese exclusively. There are many things that could be done wrong or halfway in a shop that claims to repair all makes and models foreign and domestic…You could have it done at a dealer, but it’ll cost a lot more.


#6

Pennywise pound foolish unless you plan on replacing the vehicle soon.


#7

the owners manual gives a time as well as mileage for replacing timing belts. I also have a 99 civic and it states 6 years or 90k miles whichever comes first.


#8

I thank you for taking the time to help me with this decision.

Your reply is interesting in that my 1999 Civic manual recommends timing belt replacement after 84 months (7 years), or 105,000 miles which is apparently based on published industry data showing the AVERAGE car is driven 15,000 miles per year (15,000 x 7 = 105,000). The fact that your manual is more conservative than mine, recommending replacement after only 6 years or 90,000 miles (15,000/year x 6 years = 90,000), suggests Honda is uncertain about the effect of age on failure since both recommendations are based on the same AVERAGE usage data of 15,000 miles/year but provide different recommendations. That uncertainty is compounded in my situation where usage is much less intense (2200/year) than the 15,000/year average assumed in both calculations.

Belts fail when the cumulative deteoration becomes excessive. The cumulative deteoriation depends on the annual rates of deterioration snd how many years it has been deteriorating (age.) But the annual rate of deterioration also depends on the intensity of usage during that year. This is obvious from the fact the timing belt of a car sitting in the garage will not have deteriorated after 7 years as much as one that has also been subjected to the high temperatures and flexing of one driven 105,000 miles during those 7 years. Therefore it is illogical to claim it should be replaced when either one of those benchmarks (age OR mileage) occurs because the 7 year old belt with zero miles on it will have much less accumulated deterioration than the 7 year old belt driven 105,000 miles, yet both would be replaced under Honda’s logic. Honda’s saying “which ever comes first” is the lazy way of analyzing the replacement problem. Belt replacement recommendations should be predicated upon expected accumulated deterioration based upon annual deterioration prorated on the basis of how many miles driven in each year, upon which deterioration is most strongly dependent, and not age alone upon which it is not nearly as dependent.

The point of my question was to learn whether manufacturers, have used their access to dealer service records to come up with the probability of belt failure for some specific combinations of age and mileage. It seems to me a statistical analysis of that data base will reveal how belt failure correlates with combined age and mileage. For example if it shows less than 1% of the installed belts failed in Civics having ten years of age but less than 25,000 miles on the belt, it will be a safe bet for me to keep driving my 8 year old Civic up to 2200 miles per year for a few more years. But if the data shows failures climb to 90 percent after 15 years of age with as little as 30,000 miles of use, I better not wait that long.


#9

Bernadette; you have obviously thought this problem through more than most. That is why I felt in my previous post that there was no great urgency for you to replace the belt, since you live in an area where extreme heat and extreme cold starts are absent. You also drive a car with a proven reliability and very tough standards for their suppliers.

If it makes you feel any better, design engineers usually put a 100% safety factor on such things as belts. That means that the chance of failure at the change-out time is very small (unless it is a 1990 Passat, or an obscure import), and the chance of it failing at the 200% mileage is virtually 100%.

So, with your very low mileage, and no extreme operating environment, you might theoretically go to nearly 14 years before the belt fails. Of course you would not do such a thing. Most of life’s decisions have acertain amount of risk; car manufacturers don’t like paying for warranty claims so they put change-out intervals in place to ensure good reliability for the owner and the fewest warranty claims due to wearout and accidental breakage. With Honda, due to their tough standards, accidental breakage well before wearout is calculated at 1 about in 344,000!

So, tell your husband we do not think you are a cheapskate; you merely try to make a rational decision based on perceived and calculated risk. By the way, I do this type of thing on a much larger scale for industrial machines.


#10

Someone finally agreed with you on the decision you made before you even came to this forum. You don’t have to listen to the mechanics here, who have an accumulative several hundred years experience. You takes your chances. You pays the piper.


#11

Bernadette, you seem to have some experience with heat aging of elastomers or some other area of technology. I want to add that the camshaft timing belt deteriorates mostly due to being exposed to elevated temperature and almost not at all due to visible wear according to timing belts that I have removed from my rubber timing belt equipped car. The small time and mileage increase that you mention in one of your posts may be a result of Honda’s accumulated experience with these belts in consumer’s hands rather than a change of belt material or construction or they may have found a way to reduce the usage temperature of the belt.

There has been a recent modest durability increase resulting in longer change intervals for VW belts, I am guessing due to a change from ordinary nitrile rubber to HSN/HNBR.

A belt will deteriorate extremely slowly or almost not at all at room temperature and is not exposed to UV from sunlight like tires. The conditions that a timing belt and a tire are exposed to probably have more differences than similarities.

The mileage limit will cover for a belt exposed to an elevated temperature for a given time at highway speeds. The time limit will cover for a belt exposed to an elevated temperature potentially for a similar time in a vehicle driven slowly for fewer miles along with the thinking that $500 for a new belt every 7 years is likely to be tolerated by consumers. If you drive 105,000 miles in one year, that should not be a deal breaker either for a Honda. An owner will easily dismiss the belt changing cost due to the mileage is my guess.

In short, I am agreeing mostly with what you say about a timing belt being safe to use, not over the specified mileage limit but over the specified time limit under certain driving conditions. The problem with this approach is that neither Honda nor anyone else that I know of has released verifying data to permit longer time usage with varyious yearly mileages. This data, if available, could be presented in a chart where you could pick your numbers and go with the resulting belt time limit. A potential and likely problem, however, is that a mechanic or second owner would either make a bad assessment of the usage pattern or would guess, not knowing for certain how the car was used with disastrous results once in a while. Another unknown is the life of the belt’s reinforcement, either fiberglass or wire; don’t know what yours is made of and what its life is.

Yet another variable is the climate where the car is used, Alaska, Minnesota or Florida. I can’t speak for what Honda requires in Mexico or nearer the equator. The US time and mileage limits would cover for Florida/South Texas and could be longer for northern Minnesota or Alaska. A problem here is that a car might spend its life in both locations.

The bottom line is that the belt changing requirements must be simple, effective and not be required so frequently that Hondas will be avoided because of the timing belt changing cost. You are on the right track but there is no data available.


#12

You might consider this also. A few years ago some good friends of mine bought a like new 4 year old Honda Civic with a shade over 59k miles on it.
Two weeks later while headed out of state on a snow skiing jaunt the timing belt broke and caused some major cylinder head damage.
The belt on your car is probably now over 9 years old (verified by the production date on the door tag).

You must like “Flirting With Disaster” as the old Molly Hatchet song goes.


#13

I’d replace it because of the time.

Let me tell you what happened with my father-in-law’s mid 1980’s Civic. I looked at the odometer, and it said 80k miles. I asked if they’d changed the timing belt, and they said no. I cringed, and they made an appointment.

My brother in law took the car in for the appointment, and the service advisor told him it didn’t SOUND like it needed a new belt.

That answer made me so mad. What does a timing belt with 80,000 miles on it SOUND like?

Long story short, 2 weeks later, bang. A $200 timing belt replacement turned into a $2,000 head replacement. Yes, it can happen.

Change your belt. This is very cheap insurance to preserve your very expensive Honda cylinder head (and maybe pistons, too). A Honda typically bends every single valve when they break their timing belt.


#14

Bernadette–

Are you trying to convince us or are you trying to convince yourself?

As valid as your analysis might possibly be, the fact remains that rubber ages and degrades as it sits–even in an engine that is never driven. As another reply stated, your calculated delay has the potential to be Penny-wise and pound foolish. You may wind up being correct, or you could wind up with extensive (and expensive) engine damage.

To quote that great philosopher, Clint Eastwood:
“Do you feel lucky today? Well, do you?”

I do not choose to gamble a few hundred dollars for maintenance vs. a few thousand dollars for engine repair. You may feel otherwise, but you will not convince me or the majority of other forum members who believe in timely preventive maintenance.

I sincerely wish you good luck with your questionable approach to vehicle maintenance.


#15

The manufacturers cannot account for all possible use scenarios, so any statistical analysis is based on averages. Applying any such conclusions to any single case is foolhardy. Have the belt replaced or risk major engine damage.

If you (or your hubby) want to pinch some pennies, skip the mid-grade fuel. Unless there is something wrong with the engine, it will be perfectly happy on quality 87 octane gas. Caveat: check the owner’s manual to make sure 87 octane is acceptable.


#16

Thanks, Docnick, for your two unemotional responses based on preventive maintenance experience with industrial machines.

They will be seriously considered in my “roll of the dice” decision. Not only have you presented some new facts, your opinion appears to be a collective one because you used “we” rather than “I”

Thanks again


#17

Bernadette; other posters are trying to give you good advice in the form of insurance that nothing bad and expensive will happen to your car.

I do agree that rubber will deteriorate due to age, and Honda obviously knows that your car COULD be driven across the Mojave Desert in July or the Alaska Highway in January, so there has to be a safe time limit on accelerated deterioration due to extreme heat or cold. I once owned a camper which was always parked outside, and ended replacing all tires at 12 years because of cracks, not wear. UV radiation was the culprit here.

In summary, the collective recommendations here are not contradictory; they just differ in degree of security you might want. My point is that you don’t need to rush out and replace the belt. But, if it was my car, I would do it in the next year or so, just for the peace of mind. If you leave Florida, all bets are off, and you should do it soon.

You own a car with a very long life expectancy, and with proper care will live another 10-15 years at least.


#18

Dear VDCdriver

I appreciate your input even thought it is qualitative, not quantitative. Yes rubber degrades as it ages but the problem is how fast. We need to put numbers on it before deciding how much the time it was in a cool engine sitting in the garage (due to the very low,17500, mileage) rather than in a hot engine having the allowable 105,000 miles put on it, reduced the cumulative degradation so that the allowable 7 years of age to replacement can be safely increased. This seems significant because it amounts to 2500 hours of allowable hot engine time, [(105,000/35mph) - (17500/35mph)] = 2500 hours, that the belt on my non-average Civic could safely provide but would be wasted if it was now replaced on the basis of age alone.

If there is no emperical field data relating failures to various combinations of age and mileage, hasn’t Honda used computer simulation to quantify the degragation rate in a cool environment. I suspect they have and found it to be insignificant , otherwise there would be a warning lable on belts saying “use before…” to avoid exceeding its allowable shelf-life sitting in the parts department.


#19

Dear Wha Who

Thank you for your comments. It is reassuring to see thoughtful folks in this forum appreciating that the prediction of timing belt failure has its weaknesses.

No, I know very little about elastomers. However as a geologist risk assessmnent was important because trying to save money by not recommending a blow-out preventer on a wildcat well when there was insufficient evidence the gas reservoir was not under high pressure could be disasterous to the pocketbook.


#20

Thank you ok4450

If mine was a used car whose history was questionable (like how many times did the radiator boil over subjecting the belt to extreamly high temperatures) I would disregared the fact it was not very old and get the seller to come down on the price to cover the unknown risks.

I am sure there is anechdotal evidence that belts fail before they were supposed to. However I bet there are also such stories about belts replaced on basis of time recommendations (way under on mileage) where an independent mechanic found there was a lot more miles left in it because degradation was not a problem. We just don’t hear about those stories because the owner feels like a sucker, so too embarresed to repeat it.