Preemptive maintenance


#1

In the aviation field many components are removed and replaced because of high time use or flight safety reasons obviously. To a lessor degree does it make sense to do the same for a high mileage car i.e. an altenator or fuel pump


#2

How Many Miles? what kind of car? What year? There are probably people here with experiences to share given more specific information.


#3

I have a 1999 Nissan Quest with 186,000 miles and all original equipment


#4

I really hope you’ve replaced the orignal timing belt.


#5

I think you could do pre-emptive maintenance but on what? Perhaps a better plan is to put a monthly payment into a “maintenance” account will give you the money needed when an major component should fail.

I’m retired and have 3 cars so if one needs work I can use another car. If you have a backup vehicle then put some money away and when you have a problem you have the money to get it fixed.

Or, you could put in a rebuilt motor, rebuilt transmission, new master cylinder, new starting motor, new fuel pump, new radiator, new AC compressor, new steering rack, all new wheel bearings, new CV joints, and replace all the rubber break lines. That should avoid any breakdowns as long as whoever did all the work does it correctly.

Of course all this work is way more than the car is worth. A big difference between old cars and airplanes is depreciation. Planes hold their value much longer.


#6

It’s pert-near impossible to predict when that kind of stuff is going to go out and so it would end up costing you a lot more to maintain your car that way without necessarily making it significantly more reliable. Plenty of people get hundreds of thousands of miles out of things like alternators, starters, fuel pumps, etc. but they also sometimes only last a few thousand miles too. It’d be pretty hard to pick out a good change interval.

Also auto parts aren’t necessarily manufactured and tested to anywhere near the standards of aviation parts and so replacing a 75,000 mile old OE alternator, for example, with a new one might actually make it more likely to go out in the next few thousand miles.

The only real exception that I do is I’ll change an old battery in the Fall, since those are reasonably predictable, but otherwise I just stick to doing the recommended maintenance and inspect everything else.


#7

I would not go off roading in a GM pickup unless I carried a spare fuel pump and had cut a hole in the bed so I could install it in the field. Better yet replace it every year whether it needs it or not. I really have a problem with the quality of GM fuel pumps. Kinda hard to do one in the field on a S-Blazer though.

When HEI first came out and I did a lot of off roading I carried spare parts for it,never used them. Most of my pre-emptive work decisions revolved around what I was doing with the car or airplane, off-roading or flying, if I stayed in the city or on the ground I took less precautions.


#8

The only things I would consider replacing on this car would be the timing belt and water pump. You have an interference engine in which the water pump is driven by the timing belt (I think. If it’s not, it’s located behind the timing cover and protrudes through it, driven by an external v-belt. It’s been a long time since I’ve seen one). A leaky water pump will cause the belt to fail, or just time and wear and tear. I did once replace a broken timing belt on a Quest at the request of the owner, who wanted to take the gamble on the off-chance that the valves survived unfazed, and they won. The car ran fine despite the interference design and the timing belt breaking on the highway. I would not take this as an invitation to not replace these parts, though…


#9

Don’t bother unless you have deep pockets or lots time to perform yourself.

I went 9yrs/225k on same car all original parts like that except for radiator replaced and water pump/timing belt at 100k.


#10

tlambert; in aerospace the preemptive maintenance is done, as you, say for obvious safety reasons. The CAB and other agencies require this and the plane makers have a recommended schedule as well.

In industry, some components are replaced because the equipment downtime is very expensive. So, when a plant goes into a “shutdown” or “turnaround”, many items are inspected and some are replaced based on their estimated REMAINING life. Typically a refinery should run non-stop for 3-4 years!

With an automobile you don’t normally have a high downtime cost if you have a breakdown; it does not warrant to replace things preemptively, as stated by others.

However, when changing the timing belt, we normally recommend also changing the water pump and belt tensioner, since the labor to access these items is the major cost in replacement.

If you do not operate in a hazardous area where you can get stranded, or you have no easy access to parts, such as irlandes (a regular on this forum)in Mexico, it does not pay to replace things proactively. Even on good Japanese cars, the length of time an item will last varies by up to 300%!! I made a study some years back of things like fuel pumps, starters, alternators, batteries, shocks, and found a huge variation.

Having said that, in a desert environment, like the Middle East, companies replace all belts and hoses every 2 years. And, as pointed out, many US drivers in the colder parts of the country, replace their battery every 4 years before wintwer starts.

I had the pleasure to tour the bus garages in our city and they do “tuneups” and inspections on a regular basis, but do not replace componennts preemptively either.

Personally, I kept track of a well maintained US car for 12 years through 200,000 miles.

I had 4 un-predictable failures, and 3 flat tires. Total number of trips were about 10,000. So, not counting the flats (punctures), the “mission availablity”, using military terms, was 9996/10,000 or 99.96%! All achieved without premptively changing anything, except the battery at 7 years.

To ensure reliable performance at the least cost, do the required maintenance your vehicle needs, and make sure the battery is up to scratch. When flushing the cooling system every 4 years, also replace any weak hoses. Then have a AAA membership and a cell phone and enjoy many years of happy motoring.


#11

Since the OP has told us that nothing has yet been replaced on his '99 Quest, and since the timing belt was supposed to have been replaced at 105k or 8 years–whichever comes first–he is a lucky man indeed. The question is how much longer he will continue to be lucky since that interference engine is literally living on borrowed time.

tlambert–Whether you are the lessor or the lessee of this vehicle, I strongly suggest that you have the timing belt and the water pump replaced tomorrow.

When that belt breaks (without warning, I might add), your vehicle will not be worth repairing, due to its book value at this point.


#12

[i]No, it doesn’t make sense.[/i]

If a part fails in an aircraft, it will fall out of the sky and you will be lucky to live. If a part fails in your vehicle, you will pull over and call a tow truck.

The smart thing to do is maintain your vehicle according to the maintenance schedule in the owner’s manual. Doing that will avert most break-downs. If you really worry about it, buy a AAA membership (or one form one of its competitors).


#13

To a lessor degree does it make sense to do the same for a high mileage car i.e. an altenator or fuel pump

I haven’t replaced either of those Items on any car I’ve owned in the past 30+ years…several of these cars going well past the 300k mile mark.


#14

I’ll state it a little more strongly - this would be the wrong thing to do. Replacing currently-working parts, besides all the issues mentioned, has much more risk on a car that it does with repair work done by highly-regulated mechanics on a plane. You could end up with a defective or shorter-lived replacement, or the repair could be done wrong, creating problems you didn’t have before.


#15

Agree; the oficial term for this is “maintenance-induced failure”. There is a rule that says “never take something apart to se why it is running so well”. Inspect only from the outside or with instrumentation. As Mike pointed out, some items will last the life of the vehicle, others may not. My 1965 Dodge Dart was scrapped with its original radiator, and transmission in perfect working order. On other cars, I have gone through 3 radiators.

Since a normal car breakdown will not mean loss of life or job, the downtime costs, which are a big consideration in industry, do not play a role. If I operated a car on the North slope of Alaska, I might replace my drive belts a little sooner, since rubber gets very brittle at -45F.

All the “preemptive” replacements are already listed in your ownwer’s manual; oil & filter, other fluids, air filter, fuel filter, timing belt, spark plugs, tires, and a few others. The only one we add is the water pump when the timing belt is changed.


#16

I take this approach:
I follow the owner/service manual maintenance for “severe” service.
Some fluids I do more often than the manual says:
brake fluid and power steering fluid every 2-3 years
"Long life" coolant at half the manual’s initial interval, plus a new thermostat
Auto trans fluid, back when I had an auto, every 30k miles or 3 years
Manual trans fluid at half the manual’s interval
Spark plugs remove and inspect every 30k miles or 3 years
Valve adjustment every 30k miles or 3 years
First tire rotation at half the manual’s mileage

All the above is relatively inexpensive to do, especially DIY

Fluid flushes aren’t needed. Just drain and refill early. If you change a fluid before it’s half worn out you don’t need to worry about the old fluid that’s left over. The additives in the new fluid will “refresh” the old.


#17

To address some concerns, I had the timing belt and water pump changed at the recommended interval, 105,000 miles in my case. To make a finer point consider making a road trip which a friend did in a 1997 Quest and unfortunately broke down with a failed fuel pump. After towing and repair the bill was $750.00. I could replace the pump in my driveway for about $220.00. The real issue is confidence in the car on an over the road trip. I intend to keep this horse for several more years as it is in great shape save the fact of its milage and age.

                                            Thanks for your responses