code58

That's what I ASSUMED it meant, but being a communicator, I try not to assume anything I have the opportunity to clarify. I tell my wife that even when we do our best to ASSUME correctly, (based on available information) I have come to the conclusion that ASSUMPTION are close to 50% wrong! How often have you heard someone say "well, I ASSUMED"... sadly, to often. Years ago I had a plane and flew and never ASSUMED when I asked for the tanks to be topped off, that it in fact was done. I go to the NTSB site now and then and read the Aviation accident reports. there are pilots that ASSUME their gauges must be wrong when they've asked to be topped of and the gauges don't record that. That's how they end up in the NTSB reports. Now you understand why I asked the question, though I assumed that was the answer.

hypervish

I understand, haha. That's actually pretty funny, why on earth did that man jump to the conclusion that it was his gauges that were faulty...lol

code58

Hyper- You wouldn't believe how many otherwise intelligent people lose their wits (or common sense) when in a panic situation. it is not terribly uncommon for a pilot (non-instrument rated) to "get in the soup", become completely disoriented and come out of the clouds inverted because they believe their inner ear rather than their instruments. It has cost MANY of them their lives. The same goes for the guy who asks for his tanks to be filled (he's usually off having lunch when this is supposed to go on) and when they aren't filled properly or only one is filled he ASSUMES the gauges are incorrect because he ASKED for the tanks to be topped. Or he sees that the gauges read full when he gets back and pays only to find the tank (or tanks) are RAPIDLY emptying, not realizing the lineman has been distracted and neglected to replace the caps and the negative air pressure is siphoning the fuel out at a RAPID rate. NEVER assume, ALWAYS confirm!

lastplace

Incorrect, they are non-interference. I just had my water pump "freeze" going 75 mph (185K miles). The clicking I heard for 15 seconds was the time belt skipping over the pump, then the belt snapped. towed it to McGeorge Toyota in Richmond, Va. $700 later drove away with new pump, belt & cover. The car runs like new. I asked the mechinic about interference, "never seen one do that in 20 years".

jbl-1985

After reviewing some posts from some veteran users here in this forum, I have to say that the consensus is that these engines are interference design. See the attached as well.

hypervish

These engines ARE interference.

code58

X2 hyper- the people who do not have "a visit from catastrophe" in the highly unlikely event that a TB breaks are led to ASSUME they are not interference engines. Not so, in the case of a non-interference engine, it isn't possible for the valves to contact the pistons. In an interference engine, they may or may not contact, depending on several things. Engine sudden stoppage is the normal result of a belt break, but may or may leave the particular pistons and valves in just the right position to collide. The thing that complicates it in the case of the 1MF-ZE engine is the VVT, which is what causes it to be classified as "interference" engine, but also means there is probably less chance of damage than an interference engine that is non- VVT. Those that have had a belt break (I have only read of 3 who have ever even claimed that it happened to them) and not had damage will forever believe it's non-interference. Don't waste your time trying to convince them otherwise, their experience is the only one that counts. Do try to educate those not so close minded though.

mno221

so at 75,000 miles i can hold off on getting my T/B replace for at least 15,000 miles?
Lloyd

code58

You could probably SAFELY hold off for another 75,000 mi., that is my opinion, but it is from actual experience. The timing belts on these cars ARE NOT made like the belts were when they recommended 60K mi. changes! Most look like new when changed at WELL OVER 100K mi. But it's your car, and your decision. You will get other opinions, all over the map, but I speak from knowlwdge in the business. You can do a search, the question has been asked many times before. Ultimately your car, your decision.

LXtiming

I recently had a timing belt break on my 2001 Lx470 WITH 174,000 miles. I had changed the belt at 100,000 miles, so this second belt only lasted a little over 74,000. Everything I read on the internet, led me to believe that because the 4.7 litre engine is an "interference" engine, it would be toast, i.e., bent valves, holes in pistons, etc. This is not necessarily true. I had the vehicle towed to my mechanic, he put a new timing belt on, and it started right up. He installed the timing belt kit (water pump, pulleys, seals, etc.) and it is running great. In fact, it is running better than ever! There is no way to actually "inspect" a timing belt for wear. The rule of thumb is to replace as preventive maintenance every 80-100K miles. But, as stated above, mine went out at just under 75K miles. I know I was extremely lucky that there was absolutely no engine damage. But, don't believe those who say that a timing belt failure will absolutely result in engine damage. It is possible that no damage at all will result. Don't give up. If your timing belt fails, there is still hope. Personal experience and not "hearsay."

code58

I would be really curious as to whether your mechanic replaced the belt with a genuine Lexus belt. T/L uses some of the finest parts I've ever seen used to build a car. When I replaced the belt on my DIL's RX at 97k mi. for the 1st time I couldn't believe what the belt looked like. I know it was the original belt because they bought the car new. The belt looked as though it had 20K mi, literally. No sign of wear or deterioration at all. The belts in most cars in the last 15 yrs. or so are made completely different than they used to be. VERY, VERY rare to see one break anymore. If he used AFTERMARKET parts, all bets are off. They are rarely ever the quality of the OEM belts and independent mechanics OFTEN use aftermarket parts. BTW, because an engine is an interference engine does NOT mean it HAS to do damage when a belt breaks, just means if it breaks in the wrong spot on the cycle, IT CAN. If non- interference, means it CAN'T do damage no matter where it stops.

salimshah

There can be a problem that leads to belt failure. .. such as oil leak and bad rollers etc. Milage and time is based on multiple of service intervals and 0 failure rate. So if everything is fine, statistically you can get longer life.

Salim

Dedotom

Purchased my 2000 rx300 with about 65000 miles on it. Have not had timing belt changed yet. It currently has 281,000 plus miles. I guess I should start thinking about a change.

jbl-1985

If you go by my 1999 manual, if you don't tow anything or if you don't meet the "special operating conditions" you never have to replace the belt...

maorsela

How can I tell if my 2002 with 105k has a belt wear? can someone post pics of what and where to look for?

Thanks!