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How do 2002 Sienna motors fail?

Okay, maybe I asked this question before, but if I did, I forgot. Sorry.

I have a 2002 Sienna with around 203,000 miles on it. My mileage was at one time high, but now I run maybe 6,000 miles a year, mostly in Mexico, unless we take a side trip in the US when we come back for a month or so.

I think it is maintained well. Mobil-1 EP, once a year at these low miles. May use as much as a quart in 3,000 miles, maybe less.

My concern is, how do high mileage motors fail? Sudden total break-down, or gradual deterioration and if I forget to check oil, it wipes itself out fast?

I am not sure I am asking the question correctly. But, I wonder if I am going to have warning when it goes, or one day it will just stop working without warning, as the 1989 Caravan transmission did at 180,000 miles? Or will it just get worse and worse until I realize it is time to ship it to the glue factory?

I try to anticipate failures since I am far from good repairs. Any advice appreciated.

With a whimper, not a bang…

Generally, the critical bearings and their respective wear surfaces wear until the spaces between them grow. At some point when this becomes advanced, the pump can no longer keep up the pressure at idle and bearing damage occurs. Eventually, the owner gets tired of the old beast, becomes complacent, stops checking the oil level, the level drops, and seizure happens.

Another thing that happens is that the cylinders wear, the rings wear AND lose the springiness that presses them against the cylinder walls, oil is allowed to pass by them into the cylinders and gets burned, and that exacerbates the problems aforementioned. And the engine also gets too tired to get up hills anymore.

In short, it’ll get worse and worse until you decide to ship it to the glue factory.

Of course, if you DON’t forget to check the oil it’ll run forever… albeit with gradually decreasing power, eventual oil leaks, and all the peripheral stuff failing one piece at a time. And you WILL need to replace things like main seals, cam seals, and other junk to help keep at least some of the oil where it belongs.

Components fail, that is life, most the time it is like getting old, the get up and go turns into getup and slow due to worn rings, and parts that start to fail. Probably your engine if maintained will outlast the suspension components and transmission, but you will probably get warning signs, but knowing you are up on scheduled maintenance can be a big plus.

I agree with the_same_mountainbike. Very seldom does an engine just quit if the oil level has been maintained and it has not been allowed to overheat. As the engine wears out, the oil consumption will probably increase and you may see some blue exhaust smoke, the power will decrease and with the decrease in power will come an increase in fuel consumption.

I have a 23 year old lawnmower. About 10 years ago, I had to add oil before I mowed the yard. After running the engine for an hour, the oil level would drop. There was blue smoke and the spark plug fouled more often. I installed a new short block. I was amazed at the increase in power and the drop in fuel consumption. Unfortunately, the engine is again using a little oil and emitting a little blue exhaust smoke when the engine pulls a little hard through thick grass.
Your Sienna engine will give you signs when it is ready to file its retirement papers.

Yeah - well, all of the above notwithstanding, you just never know. It could blow a rod through the block tomorrow, or the head gasket could blow, or whatever. These things are not so likely unless something has happened to compromise things, such as overheating or an oil pressure issue or something. But you might get some signs. And you might not. And if you get signs you get early ones that give plenty of warning…or not so early ones that give you less time in terms of warning.

It will start getting a bit more wheezy and smelly as time goes by,but forget it just totally giving up,it will probaly run acceptably till you decide its time for someelse to own it,I think those Toyotas are like Hondas and Nissans-Kevin (at 6K a year in a place like Mexico,it will probaly have heirloom quality{just dont put 20W-50 in it}

I don’t think Toyota or Nissan or Honda has anything to do with it. The metallurgy and tech basically move in lockstep across the industry. Whatever variation one may find isn’t going to affect general engine wear or odds of failure with the exception of known defects/problems. A lot of quality legends are a) legends and b) not really about the engines, in particular. My Ford with about 240K on the engine, for example, still has 175psi compression across the board and doesn’t burn any oil. (Leaks a little though).

Cig, anything is possible, but that was not the question.

Mountain, I’m not so sure:

Main question: “…how do high mileage motors fail?”

“Sudden total break-down” Yes, that happens.

“…or gradual deterioration” Yes if no sudden total breakdown.

“and if I forget to check oil, it wipes itself out fast?” Yep, that never helps if you want to avoid sudden total break-down.

So anyway, I thought that was the question.

Okay Cig. I can live with that. I withdraw my comment.

I think all I wanted to add to the thread was the “anything’s possible.” 200K is 200k. I figure all bets are off.

However, if it was my van, I would operate on the initial ideas given - that as long as I take care of it, it will just go indefinitely. (How else do we old weirdos get over 200K on a car - as I believe you do as well).

Consumer Reports has been saying for several years that engines have become very reliable if properly maintained and the differences between brands are modest. The great majority of cars are scrapped because of wrecks or a few other expensive problems, like transmissions. I suppose people on here are more likely to see failing engines because they don’t stress so much about driving high mileage cars. Theh are able to affordably fix a lot of problems that would send your average off to buy something newer and less aggravating. Most folks don’t appreciate a good mechanical challenge.

No problem. I do see your point.

I think I get extreme mileage for two reasons:

  1. I buy a make with a reputation for exceptional reliability
  2. I maintain it obsessively. Most people add a a quart when the oil gets down a quart. I add a half a quart when the oil gets down a half a quart. Most people wax the car when the water stops beading. I wax it before the water stops beading. Most people change their spark plugs per the recommended schedule. I change them annually. Etc. Etc.
  3. I buy basic vehicles with basic engines and without a lot of bells and whistles.

Okay, that’s three reasons, not two. My guess is that you also obsessively maintain your vehicles.


I’m pretty obsessive about everything except for the exterior. When it comes to that, I’m pretty lazy. However, I am in Central VA rather than New England. So that matters. During the winter you probably get a new dose of winter road chemicals every 5 days. I get enough of it to think about more like every 5 years. I also have two teenagers. One would think that means I have two people to wash and wax regularly - well, yeah right. It just means I have a lot of distractions. If I keep up with the oil changes and ball joints I’m a pretty happy guy.

Actually, I don’t. For most of the last decade we didn’t even own a car, using car share services (ZipCar, etc.). Late in 2012 we bought a car mainly because I had needed an ambulance ride to the hospital and my partner decided not having a car was maybe a bit risky. I agreed. Living in the middle of San Francisco and not commuting by car (or commuting at all in my case) means we aren’t putting many miles on it. But we do check the oil regularly. It’s not really due for anything else yet. We’re both software engineers and quite organized, so I think we’ll keep on top of things. So far our local Hyundai dealer has been impressive and is very convenient, and we’re not especially price sensitive, so we’ll give him the chance to sink or swim.

Before the car share era we had an 10 yo Civic that had never had any problems except people kept running into it. Got to be a bit of a joke how many ways people could hit a bright red car. My partner was seriously upset when that car was totaled as he absolutely adored it. Not too surprising after years of Volkswagens and Saabs (he was living in France, where those were considered reasonable choices.)

Back in the day when American cars wouldnt go 100K miles as a rule there these old B210s rusting around with 300 thousand miles on them,yes I think engineering and quality control has a lot to do with longetivity,my beloved (bought new) Focus dropped a valve at 100K plus and if anything it was over maintained,had several Hondas and Nissans,never had anything like the trouble I had with that car-Kevin(Hope Ford has their act together now, I’m contemplating buying one)

The whole line of Ford 1.9L through 2.0L engines from Escorts though Focus have this known valve seat problem. It goes in the category of manufacturing defect. It’s never been recognized by Ford because they don’t tend to go until they get up there in mileage. It doesn’t characterize Fords. If you want to go on a hunt for car models that have known and serious issues you won’t find the [originally] Japanese manufacturers to be free of such things.

Any car can break down at anytime, a part fails somewhere and you have to replace the part to fix it and get back running. Fuel pump, water pump, etc. A new car with all new parts is less likely to have a failure than an old car with lots of miles on all those parts. So, the old car will need more repairs more often. Some makes and models hold up better than others, so predicting a future failure is difficult. Currently I have 4 cars with the following mileages, '01 Sequoia 130K, '00 Camry 170K, '03 Civic 148K, and '04 T’bird 66K miles. If I have a problem with one, I simply use another car until I have get it fixed. If I had only 1 car I’d likely have a newer one with less miles.

The next issue is how does a high mileage car indicate its motor is just shot? Excessive oil consumption is a big clue. 1 qt every 3K miles isn’t excessive at all. Some blue smoke at start up isn’t a big deal either. When you have constant puffing of blue smoke and use 1qt of oil every 500 miles you are looking at a tired motor. Not a dead motor, just one with a lot of worn internal parts that can be replaced via a rebuild. 18 wheeler truck motors are rebuilt all the time. Another big clue is knocking and/or clacking sounds deep inside the motor. These are bearings and parts that are now so loose that they could let go and you have a catastrophic failure such as a piston rod failure. After such a failure the motor isn’t worth rebuilding, but it can be replaced if you wish.

Your Sienna could go on for many more miles and years. And, you could get stuck in the middle of nowhere with a dead fuel pump too. You simply can’t expect a 12 year old car with over 200K miles to be trouble free at that point in its life. If you are uncomfortable with an on the road breakdown I suggest it is time for a new car. The Sienna has served you well, and might go on doing so for many more years - but there will be breakdowns and repairs along the way.

I would be more concerned about the 3.0 V6 timing belt and bits. Than hope the headgaskets never leak.

Cig, having raised two kids myself, I never would have made that assumption! I take much better care of my car now than I did when the kids were growing up. And I have absolutely no regrets about that. If one of the kids came to need me again, I would, without a second thought, abandon everything to help them. I love my kids with all my heart. I only “like” my car. {:slight_smile:

Hmmmmmm… perhaps I take such good care of my car because I have no life???