Interference or Non-Interference
10-11-13, 08:50 AM
#1
Intermediate
Thread Starter
Interference or Non-Interference
Can't remember which our RX's are..........I have about 110k on my timing belt, plan to change it this week but I'd like to know anyway......
10-11-13, 10:06 AM
#2
Moderator
This thing never dies ,,,, 
Simple rule:
Lexus Variable valve engines are interfering ... and depending on circumstances (relative position of piston and valves ,,,, as controlled by VVTi) you may or may-not be in interference mode.
As you do the timing belt replacement, there are steps to ensure piston and valves do not hit each other.
Salim
Simple rule:
Lexus Variable valve engines are interfering ... and depending on circumstances (relative position of piston and valves ,,,, as controlled by VVTi) you may or may-not be in interference mode.
As you do the timing belt replacement, there are steps to ensure piston and valves do not hit each other.
Salim
10-11-13, 10:33 AM
#3
Intermediate
Thread Starter
This thing never dies ,,,,
Simple rule:
Lexus Variable valve engines are interfering ... and depending on circumstances (relative position of piston and valves ,,,, as controlled by VVTi) you may or may-not be in interference mode.
As you do the timing belt replacement, there are steps to ensure piston and valves do not hit each other.
Salim
Simple rule:
Lexus Variable valve engines are interfering ... and depending on circumstances (relative position of piston and valves ,,,, as controlled by VVTi) you may or may-not be in interference mode.
As you do the timing belt replacement, there are steps to ensure piston and valves do not hit each other.
Salim
10-11-13, 11:44 AM
#4
Moderator
For non interference Lexus/toyota engines the T-belt is removed at TDC,
Mind you, when the belt is put on, you verify the marks match at TDC after 2 cranks. Remember to ignore the marks on the belt itself ,,, they will be way off.
Salim
10-12-13, 12:55 AM
#5
Get used to it Salim, as long as these engines live (Rx belt driven cam), this question will live with them. (can't help but chuckle) (and there will always be controversy, but you did give the right answer)
10-12-13, 05:53 PM
#7
Moderator
Now you are asking about odds vs facts.
I have come across multiple (less than you can count on one hand) where there was no damage and one where there was.
Trust me when I say the engine is interfering type.
Salim
Last edited by salimshah; 10-12-13 at 07:18 PM.
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10-13-13, 12:12 AM
#8
I worked with a fellow who bought a Ford Ranger new in 1988. At 180K+ miles the odometer broke. He drove it for another 1&1/2 -2 years with no odometer. One morning coming to work it quit unexpectedly. Had it towed to Ford and diagnoses was broken timing belt. 2 hours later was on his way to work. He estimated he had 250K mi on it and he discovered it called for a 60K mi replacement. He DIDN"T EVEN KNOW IT HAD A TIMING BELT! Only one mans opinion but I think too many people worry too much about timing belt replacement. Blow up at 90,001 mi.? Probably not. These belts look pretty new at 90K mi.
10-13-13, 06:38 AM
#9
Lexus Test Driver
The Sienna that I just purchased has 142k miles on the original timing belt (never been replaced, however all other service has been done, kinda weird the dealer didn't mention it as it's been dealer maintained it's whole life), anyways I'll be changing the timing belt soon.
I will be sure to grab a few pictures of the belt at what will likely be about 145k miles.
I wouldn't go more than 120k miles max on the timing belt. Why risk it? You are going to have to change it sooner or later. Might as well get it over with and not chance being stuck with bent valves.
I will be sure to grab a few pictures of the belt at what will likely be about 145k miles.
I wouldn't go more than 120k miles max on the timing belt. Why risk it? You are going to have to change it sooner or later. Might as well get it over with and not chance being stuck with bent valves.
10-13-13, 07:22 AM
#10
Pole Position
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I have 163K on my '03 RX with the original TB. Call me a gambler... But I helped a friend replace the TB on his '01 RX (bought new) with 187K miles and the original TB showed hardly any wear.
Love to see what the Sienna TB looks like after 145K.
10-13-13, 08:55 AM
#11
Intermediate
Thread Starter
Also at issue when approaching or passing the 200k mark are the water pump and associated idler/tensioner pulleys the timing belt rides on.
This will be the second time I change the belt but only the first for those associated components.
This will be the second time I change the belt but only the first for those associated components.
10-14-13, 12:09 AM
#12
Not a trust issue. I have no doubt it's an interference engine. I was just curious about the "odds'.
I have 163K on my '03 RX with the original TB. Call me a gambler... But I helped a friend replace the TB on his '01 RX (bought new) with 187K miles and the original TB showed hardly any wear.
Love to see what the Sienna TB looks like after 145K.
I have 163K on my '03 RX with the original TB. Call me a gambler... But I helped a friend replace the TB on his '01 RX (bought new) with 187K miles and the original TB showed hardly any wear.
Love to see what the Sienna TB looks like after 145K.
P.S. ONLY use OEM replacement belts! All bets are off on any other. I know from experience!
10-17-13, 02:58 PM
#13
Its interesting that the Lexus Knowledge center opts out of getting into a discussion of potential catastrophic damage of a broken T-Belt on the website.. If it breaks, your car won't work until you get it repaired. Really?