How many miles on your TIMING BELT when it failed? What happened? (1 Viewer)

[LC neophyte]

I know the maintenance schedule for replacement. I would like to know just two things:
1) How many miles on the timing belt, not the vehicle, when you had belt breakage, not just slippage or PM replacement?
2) What were the immediate mechanical or electrical effects on the engine?

Essentially, I'm just curious of what would really happen, and how frequently we might see this in our community. Maybe it's a kind mythical warning that happens so rarely, that we over worry.

Again, only respond if you had complete breakdown of the timing belt, not how long you got out of your belt before you decided to change it.

 

[Riviera]

Timing belt won't really slip, maybe skip, but not slip. It's a toothed belt, not a grooved belt. Furthermore, it's an interference engine, I'll go the recommended 90k, personally. There's someone on here right now that just had a belt break. I can tell you, you're playing with fire if you're wanting to roll the dice on this but extending the timeframe . Mechanical or electrical (electrical????? What???). The engine won't run, at best. At worst, the pistons slam into the valves and you have to get a new engine.

 

[davegonz]

The timing belt on my 1999 went before I owned it. I know the mechanic that tore it down and he said that there was no sign of any damage. That was at 125k miles. The truck currently has 225k with no engine related issues.

 

[Matthew810]

Definitely watching this thread out of curiosity even tho my rig had belt changed 10k ago. I'd be interested in knowing if those that do break are more an issue of age of belt rather than mileage.

 

[davegonz]

Before you flame me, there are others out there that have had timing belts break with no damage.

Timing belt failure, 07 LC

The vehicle is my uncles '07 TLC with 136k. Timing belt was replaced at 91k in 2013 by Jim Hudson Lexus in Augusta, Georgia. My uncle was driving it when all of the sudden it shut off. The engine just turned off. The vehicle has power, first thought was maybe bad gas, clogged fuel filter...

forum.ih8mud.com

 

[Brandon Ryder]

I'll let you know after i replace my timing belt this weekend. wife was driving and the engine just shut off. she was going maybe 25mph. check engine light and battery light came on as she rolled to the side of the road. i tried to crank it when i got too her but it wouldn't start. has a p0340 code crack shaft position sensor.

those are the signs when it happens. belt broke basically in half. right around 90k since it was replaced. it's a gates belt. nothing else failed that caused the belt to break to my knowledge. water pump and idlers spin freely. previous owner also had a timing belt break on him when he changed it last. engine was fine. I'm hoping it's fine again. this is a 2000 lc by the way.

 

[FxFormat]

My current coworker is a Toyota master mechanic, he has never seen a factory timing belt on a 4.7 break, ever, he's seen a few break, after someone had changed it.

He has 250K miles on his 4runner 4.7, original belt, his father in law, sequoia, almost 300K miles, same factory belt. If i bought a cruiser with the factory belt, i wouldn't change it, however if i know it's been changed, i would personally open it up and change it myself, knowing it'll be done right, and using the right parts.

A lot will argue with me about this, but based on experiences, and what i've read, led me to my opinions about timing belts.

 

[Riviera]

Personally, I used a mitsuboshi (not mitsubishi) belt on mine, and I believe that's an OE belt (maybe not). At any rate, I have bad luck, and I'm not wanting to experience a broken belt.

 

[97 AZ LC]

Timing belt won't really slip, maybe skip, but not slip. It's a toothed belt, not a grooved belt. Furthermore, it's an interference engine, I'll go the recommended 90k, personally. There's someone on here right now that just had a belt break. I can tell you, you're playing with fire if you're wanting to roll the dice on this but extending the timeframe . Mechanical or electrical (electrical????? What???). The engine won't run, at best. At worst, the pistons slam into the valves and you have to get a new engine.

Interference engine, 90k interval, playing with fire, rolling the dice, pistons slam into valves, have to get a new engine - all seem to be true but only for the 06-07 VVT engine. If I had one I would certainly change it every 90k.

 

[Riviera]

This has been kicked around before, of course. Interference? I just have bad luck and like to err on the side of caution. Others do as they seem fit, and I've searched a bit and don't see anyone with an early 100 that trashed their engine.

 

[Jason YY]

Mine did , no damage can’t remember the mileage when it happened. Belt that broke had less than 90k on it.
Had it repaired at toyota dealer , and will have the next one done there as well on schedule.

 

[dirtEJohnson]

The belt is only one of the "wear" items on a 90k engine service. MAYBE a factory belt will run forever, but after having done a couple hundred t-belt jobs through the years, failures noted are not just belts. Tensioners, idlers, keepers, leaky seals, weeping water pumps and even improperly installed dust shields have led to breakdowns. Doing it by the schedule and by the book is the only sensible thing to do if you care at all about your engine.

 

[TheDan]

I am under the impression that 98-05 are non-interference engines, and that 06-07 "vvti" are the variable valve timing engines where you have the possibility of smashing things up if the belt breaks. However, after reading the forum here for two years- i havnt seen a toasted engine thread on this forum 'yet' due to a broken belt. Some even say that the 06-07 model engines will be ok if they break.

 

[fro20fow]

Again, only respond if you had complete breakdown of the timing belt, not how long you got out of your belt before you decided to change it.

Because most responses are ignoring this, I'll chime in as well:

Outside factors such as non OEM components and/or water pump failure can cause timing belt issues. Not Flushing coolant (using incorrect coolant) can cause water pump issues. Point is, when you see/hear about a breakdown of a timing belt, there will be an outside contributing factor.

 

[LC neophyte]

I'll let you know after i replace my timing belt this weekend. wife was driving and the engine just shut off. she was going maybe 25mph. check engine light and battery light came on as she rolled to the side of the road. i tried to crank it when i got too her but it wouldn't start. has a p0340 code crack shaft position sensor.

those are the signs when it happens. belt broke basically in half. right around 90k since it was replaced. it's a gates belt. nothing else failed that caused the belt to break to my knowledge. water pump and idlers spin freely. previous owner also had a timing belt break on him when he changed it last. engine was fine. I'm hoping it's fine again. this is a 2000 lc by the way.View attachment 1927592

Outstanding evidence! You mentioned miles on the belt. How about age? Living in your part of California, do you think that heat and arid conditions play a role in degradation of the belt?

 

[LC neophyte]

Mine did , no damage can’t remember the mileage when it happened. Belt that broke had less than 90k on it.
Had it repaired at toyota dealer , and will have the next one done there as well on schedule.

Would you happen to know the age of the belt? Was it original equipment?

 

[LC neophyte]

Because most responses are ignoring this, I'll chime in as well:

Outside factors such as non OEM components and/or water pump failure can cause timing belt issues. Not Flushing coolant (using incorrect coolant) can cause water pump issues. Point is, when you see/hear about a breakdown of a timing belt, there will be an outside contributing factor.

Ah! didn't know that. Are you saying that a mechanical failure of the water pump, or pulleys, etc. will increase the load on the belt and lead to premature failure? Good point if I understand you. I wonder how one would do PM on those components (excluding water pump)?

 

[LC neophyte]

The belt is only one of the "wear" items on a 90k engine service. MAYBE a factory belt will run forever, but after having done a couple hundred t-belt jobs through the years, failures noted are not just belts. Tensioners, idlers, keepers, leaky seals, weeping water pumps and even improperly installed dust shields have led to breakdowns. Doing it by the schedule and by the book is the only sensible thing to do if you care at all about your engine.

Good point. Having done "a couple hundred t-belt jobs" shows your experience. Would you share with us any PM tips other than scheduled PM that we can do to ensure optimal mechanical performance on the timing belt mechanicals?

 

[cwmoser]

Here are photos of the Timing Belt I replaced on my 2004 LC.
Belt had 114,200 miles on it and and 6 .5 years age.
It looks almost brand new to me - no cracks or wear anywhere.
It did not break - just replaced out of fear.
Miles were primarily Southern USA miles - mostly Florida and N.C.

After noting the condition of this belt, I feel more confident in leaving my 2002 LX470 alone as it has 46K miles and 16 years old.
I'm thinking I will be focused on listening for squeaks and leaks than a factory schedule.

 

[BullElk]

Changing timing belts at 90k intervals is yet another method The OCD crowd uses to skew the mythical high cost of owning a Land Cruiser.