Changing timing belt

i have a 2003 toyota sequoia with 109000 miles and iam worried about the timing belt breaking . I can’t afford to have ot changed right now . Anyone drove this many miles without changing it . they say to change them at 90000

Does the engine HAVE a timing belt? The Gates (a belt maker) lists the 4.7L V8 engine as having a timing belt. See for youself at

If you can’t afford to have the belt changed now, can you afford to replace the cylinder heads in the near future? We’re talking a few hundred versus a few thousand dollars. Your choice. It’s an interference engine almost 20K miles past MTBF. Do it or regret it.

I have an '01 Sequoia and I got the belt changed at 90K. Didn’t want to face the $$$$$ to replace the engine if the belt broke. It is an interference motor meaning the pistons hit the valves if the belt breaks. A couple of pistons some new valves and new heads pretty much means a new, used, or rebuilt motor.

My advice is find the money, or park the Sequoia until you have the money. My job was just over $550 from a good independent garage. Toyota dealer wanted several hundred more for the job. I’m at 109K now too, but I’m feeling more comfortable than you at the moment.

This post may be a plot by a rival brand to get someone to think before they buy a vehicle with a timing belt instead of a timing chain.

Or it may be a legitimate question from an economically challenged individual who needs good advice. Are you a conspiracy nut?

Do you work for Toyota? Please state three consumer advantages of timing belts. I’ll give you one. They are quieter than chains.

Have any mechanical skills? Timing belts are not terribly expensive, but the labor to change one is pretty extensive. Moreover, this engine apparently uses the timing belt to drive the water pump. Whoever repairs it will strongly recommend replacing that as well. Regretably, this is a job that is probably a bit too complex for someone who has no prior experience working on cars. And it requires some specialized tools.

Unless the vehicle is in extraordinarily sad shape and simply isn’t worth the cost of replacing the timing belt, you don’t really have much choice.

So, I think your choices are:

  1. Pay to get the belt (and waterpump) replaced.

  2. Drive it until the belt fails then pay for a new engine/major engine rebuild.

  3. Sell it and use the money to buy something that you can either work on yourself or afford repairs on.

  4. Learn a lot about automobile repair quickly and then do the work yourself.

  5. Drive it until it breaks. Scrap it. And buy a bicycle.

They are more compact than chains and therefore allow more flexibility in motor design. They are lighter than chains and over time might save a bucket of gas or two.

Although rare, timing chains can break too. You may purchase a vehicle strictly to get a timing chain over a belt, but that doesn’t mean you’ll necessarily spend less on maintenance and repairs over the life of the vehicle.

From time to time, we get people wondering about the timing belt in their vehicle. When we, finally, finally, find out what engine is in the vehicle, after numerous responses, we find that their particular engine DOESN’T have a timing belt.
Do you know if the engine is a four cylinder, a six cylinder, or a V8 engine. It might further help if you know, and report here, the size (in liters) of the engine.

All Sequoia’s come with a V8, I believe it is 4.7L. I have an '01 Sequoia with the same size motor and it is an interference engine.

For interference engines…

If you keep your vehicle past 250k miles then you’ll probably need to have the chain replaced. Chains do stretch over time. And when they stretch they can slip…when a chain slips in a interference engine…good-bye engine. ONE timing chain replacement is probably more expensive then 3 timing belt replacements.

Replacing a timing belt is a lot less complicated then replacing a chain. Thus…it’s a job for many back-yard mechanics…Replacing a chain on the other hand is much more involved (like dropping the oil pan). Parts are far more expensive…and it’ll take you a 2-3 times longer which may require some special equipment.

MTBF stands for Mean Time Between Failure, so if the MTBF were 90K miles, half the Sequoias on the road would have broken their belts before reaching that mileage. If the factory recommended interval is 90K miles, then that’s their minimum expected life, else the factory would have to pay for some new engines for properly-maintained cars. I’m sure lots of people have driven them well over the recommended service interval, though admittedly at increasing risk with increasing miles. Drive gently and good luck.

MTBF is the wrong designation for the change interval. If that was true Toyota would loose a bunch.

Generally, such belts have a 100% safety margin if made by/for Toyota or Honda, a very much smaller margin if Volkswagen. My neighbor’s Passat belt failed at 55,000 miles and the change interval was 60,000!!! All Japanese statistics would be based on actual test results.

A Toyota or Honda belt running the full change interval in a normal environment woud be allowed 1 bad one in 234,000 units (Six Sigma quality), there is a good chance that OP can drive a little longer with very low probability of failure. It’s likely that all belts in a sample tested would fail at 2 times the interval, such as 180,000 miles. This assumes no overheating, no dirt or oil contamination, properly aligned pulleys, etc.

That’s an expensive gamble. Once past the recommended mileage or time interval, the risk of breakage starts to climb logarithmically. At 19,000 miles past recommended change interval, he’s at the 121% mark. Living a dangerous life. I’d rather spend $550 and have peace of mind than have the belt snap and face $3000 or more in engine repair. Hell, $3000 is probably underestimated, since this engine also has 4 valves per cylinder.

check your manual…it will give mileage when to change at 90,000 OR number of months ( ??? ) which ever comes first…after that it is a gamble … as many have said cheaper to change it out now than to have it break later…

My 1994 Toyota Camry just broke down, not sure what it is yet - does it have a timing belt?