when to change timing belt on es 300?
#2
That being said, I've seen people go 175-200k on the original timing belt (not that you should). The 1MZ in all its variants is non-interference, so if your belt snaps there will be no valve or piston damage.
#3
Lexus Test Driver
#4
Lexus Champion
Official Toyota recommendation using the updated HSN Mitsuboshi belt (which your car would fall under) is every 90k or 6 years, whichever comes first.
That being said, I've seen people go 175-200k on the original timing belt (not that you should). The 1MZ in all its variants is non-interference, so if your belt snaps there will be no valve or piston damage.
That being said, I've seen people go 175-200k on the original timing belt (not that you should). The 1MZ in all its variants is non-interference, so if your belt snaps there will be no valve or piston damage.
Last edited by PFB; 06-21-17 at 11:38 AM.
#5
#6
#7
Lexus Test Driver
The point here is that you don't want your timing belt to snap whether it is interference or non-interference engine.
If the timing belt snaps while you are driving on a busy highway, you will lose power steering, vacuum assisted braking, etc...If the vehicle has stopped in the middle of the highway, you are creating a hazard.
If the timing belt snaps while you are driving on a busy highway, you will lose power steering, vacuum assisted braking, etc...If the vehicle has stopped in the middle of the highway, you are creating a hazard.
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#8
The point here is that you don't want your timing belt to snap whether it is interference or non-interference engine.
If the timing belt snaps while you are driving on a busy highway, you will lose power steering, vacuum assisted braking, etc...If the vehicle has stopped in the middle of the highway, you are creating a hazard.
If the timing belt snaps while you are driving on a busy highway, you will lose power steering, vacuum assisted braking, etc...If the vehicle has stopped in the middle of the highway, you are creating a hazard.
#9
The 1MZ VVTi is non-interference. Proven time and time again.
I used to think that too, until somebody on Toyota Nation pointed out that there is no change in valve lift (not VVTi-L). So if you turn the camshaft on a non-VVTi engine (with the timing belt off) to open up valves, and then turn the crank and it doesn't hit (done this twice, once with the head unbolted to check, it's non-interference, and so is the VVT-i engine as valve timing changes don't matter if they're never physically sharing the same space as the piston.
Here's one thread, there are many like it: http://www.toyotanation.com/forum/10...erference.html
...and another: http://www.toyotanation.com/forum/10...ming-belt.html
...hardtop is usually the one called on to correct misinformation on this front, but there are others. Do a search.
...I'll put my money where my mouth is instead of talking smack: I have a timing belt change coming up in 30k on a VVTi engine. I'll take the belt off, make sure on one cylinder that the valves are lifted to max, then crank the starter and take video. It'll be a while, but if I'm wrong or lying about any of this, you guys will hear all hell breaking loose. as my valves bend.
That being said, the 3MZ is interference because they changed the pistons.
EDIT: There was a guy on TN recently with a gen3/4 Camry with a non-VVTi 1MZ. I think he had damage because something was seriously wrong with his valves and/or rods, as his pistons were hitting his valves which he took off the head to verify. Worth noting that Toyota claims the non-VVTi engine is non-interference.
I used to think that too, until somebody on Toyota Nation pointed out that there is no change in valve lift (not VVTi-L). So if you turn the camshaft on a non-VVTi engine (with the timing belt off) to open up valves, and then turn the crank and it doesn't hit (done this twice, once with the head unbolted to check, it's non-interference, and so is the VVT-i engine as valve timing changes don't matter if they're never physically sharing the same space as the piston.
Here's one thread, there are many like it: http://www.toyotanation.com/forum/10...erference.html
...and another: http://www.toyotanation.com/forum/10...ming-belt.html
...hardtop is usually the one called on to correct misinformation on this front, but there are others. Do a search.
...I'll put my money where my mouth is instead of talking smack: I have a timing belt change coming up in 30k on a VVTi engine. I'll take the belt off, make sure on one cylinder that the valves are lifted to max, then crank the starter and take video. It'll be a while, but if I'm wrong or lying about any of this, you guys will hear all hell breaking loose. as my valves bend.
That being said, the 3MZ is interference because they changed the pistons.
EDIT: There was a guy on TN recently with a gen3/4 Camry with a non-VVTi 1MZ. I think he had damage because something was seriously wrong with his valves and/or rods, as his pistons were hitting his valves which he took off the head to verify. Worth noting that Toyota claims the non-VVTi engine is non-interference.
Last edited by nsghtbrwry; 06-22-17 at 05:20 PM.
#10
Are you sure a test on a cold non-running engine will accurately simulate the full range of dynamic possibilites on a hot engine?
PS I am not talking smack, just pointing out I have been reading Lexus and Toyota message boards since they started 20-25+ years ago and many experts have expressed different views on this issue.
PS I am not talking smack, just pointing out I have been reading Lexus and Toyota message boards since they started 20-25+ years ago and many experts have expressed different views on this issue.
#11
Are you sure a test on a cold non-running engine will accurately simulate the full range of dynamic possibilites on a hot engine?
PS I am not talking smack, just pointing out I have been reading Lexus and Toyota message boards since they started 15+ years ago and many experts have expressed different views on this issue.
PS I am not talking smack, just pointing out I have been reading Lexus and Toyota message boards since they started 15+ years ago and many experts have expressed different views on this issue.
EDIT: My bad, wasn't insinuating that you were talking smack. Just covering my own ***, trying to set up a test and don't want to seem confrontational
#13
Well, the guy quotes from Wikipedia, and I quote his quote, "They feature cast aluminium pistons with an anti-friction resin coating (moly) and valve depressions that decrease the chance of valve-to-piston interference in case of timing belt failure on motors without VVT-i."
I just checked the piston part numbers for a 2000 Camry V6 (non-VVTi) and a 2000 Avalon (VVTi), and they're both the same:
Right bank: 13101-20030
Left bank: 13301-20020
I mean, if the timing belt breaks, it doesn't matter if the engine has variable valve timing or not; valves have the same lift, so can potentially stay open at their maximum lift/open position and the chance of damage is the same. If the cast piston depressions bring that chance down to zero, then that's that I guess. It says the pistons are cast aluminum, I don't know if they're hypereutectic, how much they would expand when the motors at operating temperature, etc. I'm talking about what I feel is the worst-case scenario with TB failure: you're driving along the highway, you stomp on the gas to pass, shooting the RPMs past the VVT crossover, and it snaps.
I'm not discounting the Wikipedia article (and by proxy the guy quoting it); it does say "decrease the chance of valve-to-piston interference" so maybe under certain conditions things can go FUBAR. In any case, I've hijacked this thread long enough, I'll start a new one when it's time to do my test at 180k.
I just checked the piston part numbers for a 2000 Camry V6 (non-VVTi) and a 2000 Avalon (VVTi), and they're both the same:
Right bank: 13101-20030
Left bank: 13301-20020
I mean, if the timing belt breaks, it doesn't matter if the engine has variable valve timing or not; valves have the same lift, so can potentially stay open at their maximum lift/open position and the chance of damage is the same. If the cast piston depressions bring that chance down to zero, then that's that I guess. It says the pistons are cast aluminum, I don't know if they're hypereutectic, how much they would expand when the motors at operating temperature, etc. I'm talking about what I feel is the worst-case scenario with TB failure: you're driving along the highway, you stomp on the gas to pass, shooting the RPMs past the VVT crossover, and it snaps.
I'm not discounting the Wikipedia article (and by proxy the guy quoting it); it does say "decrease the chance of valve-to-piston interference" so maybe under certain conditions things can go FUBAR. In any case, I've hijacked this thread long enough, I'll start a new one when it's time to do my test at 180k.