Toyota 1MZ-FE, original timing belt at 292k

[bbhero]

Well that totally contradicts what I have looked up via the website Trav put on here ... Carangel I think...... Clear as day it says the VVT-i is a interference motor... I saw a video on a Toyota site and the guy certainly verified what you said... I guess the carangel site has that one Toyota motor listed wrong. I know their other V6 3.0 motors and 2.2 L motors are non interference.... Too bad my Nissan Altima VQ is a interference motor.

 

[artbuc]

Originally Posted by bbhero

Originally Posted by kschachn

Originally Posted by painfx

The owner must have been ignorance or cheap. This is an interference engine. One snap it is game over. Looks like he got lucky.

No it is not an interference engine. I have changed timing belts on numerous 1MZ-FE engines and you can rotate the crankshaft with the cams in any position.

Ahh the 1MZ VVT-i motors are interference motors... The regular 1MZ-FE 3.0 L motors are non interference motors like you said... True...

This debate has been going on for as long as the VVT-i has been around. Used to pop-up on ClubLexus on a regular basis. There was a poster there named code58. IMO, the only person who could rival is knowledge is Trav. Based on a lot of research, code58 came to believe the V6 VVT-i was generally non-interference but, under certain conditions, could interfere. So, if you lose a TB you could be ok or you could do major damage. Definitely there were cases of both happening.

 

[dblshock]

so many of this gen still on the road, very few rusted either.

 

[artbuc]

Originally Posted by dblshock

so many of this gen still on the road, very few rusted either.

My Avalon will be 21 yo in August. Have fixed a few minor rust spots over the years but she is still in amazing condition. Of course she lives in a garage and has been meticulously cared for. Just over 150k miles.

 

[supton]

Originally Posted by PowerSurge

Tough to beat Toyota quality.

Mother Nature and road salt sure do try (and succeed).

 

[kschachn]

Originally Posted by artbuc

This debate has been going on for as long as the VVT-i has been around. Used to pop-up on ClubLexus on a regular basis. There was a poster there named code58. IMO, the only person who could rival is knowledge is Trav. Based on a lot of research, code58 came to believe the V6 VVT-i was generally non-interference but, under certain conditions, could interfere. So, if you lose a TB you could be ok or you could do major damage. Definitely there were cases of both happening.

I agree there was a lot of discussion on that, but you've seen documented cases of valve clash on these engines when the belt breaks? I've never seen one, just wondering if you have. People talk about it on the interwebs but I've never seen a post where damage occurred. In fact I'm not sure I ever saw pictures or instances of a belt breaking on these engines at all.

 

[artbuc]

Originally Posted by kschachn

Originally Posted by artbuc

This debate has been going on for as long as the VVT-i has been around. Used to pop-up on ClubLexus on a regular basis. There was a poster there named code58. IMO, the only person who could rival is knowledge is Trav. Based on a lot of research, code58 came to believe the V6 VVT-i was generally non-interference but, under certain conditions, could interfere. So, if you lose a TB you could be ok or you could do major damage. Definitely there were cases of both happening.

I agree there was a lot of discussion on that, but you've seen documented cases of valve clash on these engines when the belt breaks? I've never seen one, just wondering if you have. People talk about it on the interwebs but I've never seen a post where damage occurred. In fact I'm not sure I ever saw pictures or instances of a belt breaking on these engines at all.

I was going to edit my post to address that point. So few TB's break I doubt if data exists proving the point one way or another. My memory is a little foggy but I believe code58 was able to show interference or knew of someone who did an experiment. All I really know for sure is that he concluded the VVT-i could interfere under certain conditions. Various parts look-up catalogues, eg Gates, give conflicting info. Maybe only the Toyota engineers know for sure.

 

[Ram02]

Wow that's great I'm tell my neighbor not to change the timing belt on his Honda Pilot he had 110k on it now. Why waste money

 

[bbhero]

You see kschachn... I ain't totally way, way off Thank you artbuc for your insights and information. Does seem like a case by case circumstance... And I'd bet that's why the carangel site just put that VVT-i motor as a interference motor... Just in the wrong circumstance it could be a bad deal...

 

[blufeb95]

Originally Posted by bbhero

You see kschachn... I ain't totally way, way off Thank you artbuc for your insights and information. Does seem like a case by case circumstance... And I'd bet that's why the carangel site just put that VVT-i motor as a interference motor... Just in the wrong circumstance it could be a bad deal...

I'm guessing the circumstance is that you're flooring it and VVT is engaged, I'm guessing that when the cam shifts over maybe it has more lift and pushes the valve into a range where it can interfere with the piston, when you're really flooring it sounds like a good time for the belt to break

 

[artbuc]

Originally Posted by Ram02

Wow that's great I'm tell my neighbor not to change the timing belt on his Honda Pilot he had 110k on it now. Why waste money

Well, for one thing the Pilot is definitely interference,,,no debate. Also, if your neighbor plans to keep the Pilot he will have to do at least one TB replacement so all he will be gaining is the time value of money which is pretty close to zero. Oh, the Honda hydraulic tensioners are notorious for failing first which will take out a perfectly good TB. He could probably get by with just replacing belt and tensioner but he should definitely get that done sooner than later unless he is getting ready to ditch the Pilot.

 

[The Critic]

Originally Posted by getawheel

This is a tough one to figure out. The owner pays to have anything fixed when it breaks, but does no preventative maintenance whatsoever. I can't explain it. It would be far cheaper in the long run to do regular fluid and filter changes and other maintenance items.

I have customers who are the opposite - they will do every wallet flush, but will defer any actual repair work.

 

[Beria]

Originally Posted by kschachn

Originally Posted by painfx

The owner must have been ignorance or cheap. This is an interference engine. One snap it is game over. Looks like he got lucky.

No it is not an interference engine. I have changed timing belts on numerous 1MZ-FE engines and you can rotate the crankshaft with the cams in any position.

Ahh the 1MZ VVT-i motors are interference motors... The regular 1MZ-FE 3.0 L motors are non interference motors like you said... True...

The 1mzfe is definitely a non interference engine. How I know? The belt broke on me while driving, no damage.

 

[Nick1994]

How sure are you that the belt was original?

6 years ago I had a 97' Camry 2.2L with the original timing belt at 185k miles, it was cracked really bad when I replaced it.

 

[Hogwash]

Toyota makes the best cars Working on the 1MZ is scary and difficult, which is why people put it off. I hope you replaced the valve cover gaskets too

Other than the occasional timing belt replacements and the tough rear spark plug change....the 1MZ and 3MZ were the smoothest most durable V6s Toyota has ever made. Some would argue the 1GR is right up there. But it's stroke is too long to ever be as silky as the MZs.

 

[michaelluscher]

Originally Posted by painfx

The owner must have been ignorance or cheap. This is an interference engine. One snap it is game over. Looks like he got lucky.

No it is not an interference engine. I have changed timing belts on numerous 1MZ-FE engines and you can rotate the crankshaft with the cams in any position.

I've heard enough debate that it seems better to err on the side of caution

What I do know for a fact is the 3MZ derivatives (punched out from 3.0 to 3.3 liters) are a VERY interference engine

And that even non interference engines may experience slight damage depending on what the VVT system was doing at impact

 

[Nayov]

Straight from the Lexus owners site the timing belts are "very reliable", but maybe-perhaps change at 90,000 miles, or not...just like the "lifetime" ATF concept, don't, or do change it/ whatever.


What is the factory recommendation to have the timing belt replaced?

Our timing belts have been very reliable. However, the timing belt is subjected to severe stress if the vehicle is operated under extensive idling or low speed driving for long distances, such as in heavy commercial use like delivery, taxi or patrol car. If the timing belt breaks, the engine will stop running and will not restart until it is repaired. While it is possible that the original timing belt may last the life of the above engines, for peace-of-mind, the timing belt may be replaced every 90,000 miles. Also, if major engine work is performed, such as a valve job or engine rebuild, the timing belt should be replaced.

 

[SubLGT]

Is the belt manufactured by Mitsuboshi ?

 

[MrPlow]

1mzfe VVT-I verified without a doubt to be non-interference at least at lower rpm. Maybe the dynamics change a little at near redline that could cause interference to a small degree?

 

[doublebase]

Wow almost 300k on a timing belt. That’s pushing it. Got to hand it to Toyota...might be the best built cars on the road today.

I own a 2016 Avalon...it’s almost a bore to not have to worry about oil consumption or anything else. Haven’t had a vehicle like that in a long time.