I have a 1999 Sienna. Did some research found a couple conflicting indications that the engine is or is not an interference engine. The guy I bought it from says it is not an interference engine. But even the Gates website contradicts itself. It has 182k miles and runs really well. The guy I bought it from had bought it a few months earlier from a guy that replaced the Sienna with another vehicle. He had always maintained well, but don’t know if he had replaced the timing belt for sure. I suspect he had, but don’t want to take any chances.
Gates says NO. How does it contradict itself? It says it’s not an interference engine. If it was, there would be bold red letters saying so.
The vehicle shown is not an interference engine unless noted “Interference Engine Application” in the comments column of the Cam Belt application section.
Timing Belts & Components
Timing Component Kit
Timing Belt Component Kit TCK257
Does not include cam. tensioner hyd. assy.
Timing Belt Component Kit W/Water Pump TCKWP257
Cam. Belt Automotive Timing Belt T257
Cam. Idler Pulley Timing Belt Pulley T42030
Cam. Tensioner Hyd. Assy. Timing Belt Tensioner T43096
Cam. Tensioner Pulley
Timing Belt Tensioner T41075 Does not include cam. tensioner hyd. assy.
Cam. Seal
Timing Component Seal KS14671 4 Required
Crankshaft Seal
Timing Component Seal KS15818
In addition to the Gates site saying it’s not an interference engine, I have that exact same vehicle. I’ve personally changed the timing belt twice and can attest to the camshaft’s ability to spin freely when the timing belt is off.
Even though it’s non-interference, you still want to replace it when it’s due. Do you really want the belt to decide to suddenly break when you’re doing 70mph on a highway sandwiched between large tractor trailers?
The reason I am saying Gates contradicts itself is because the Gates Timing Belt Replacement Guide available from their site at the following link indicates on page 23 that the Sienna 3.0 V6 engine is indeed an interference engine. Which is the correct information? Someone posted here that they had changed the timing belt out and found it to be a non-interference engine. That is helpful to me and others that will read this post, but if using the Gates website you will get contradictory information.
http://www.gates.com/downloads/download_common.cfm?file=428-1466_web.pdf&folder=brochure
The reason I am saying Gates contradicts itself is because the Gates Timing Belt Replacement Guide available from their site at the following link indicates on page 23 that the Sienna 3.0 V6 engine is indeed an interference engine. Which is the correct information? Someone posted here that they had changed the timing belt out and found it to be a non-interference engine. That is helpful to me and others that will read this post, but if using the Gates website you will get contradictory information.
I attached the PDF doc to this reply.
http://www…r=brochure
The reason I am saying Gates contradicts itself is because the Gates Timing Belt Replacement Guide available from their site at the following link indicates on page 23 that the Sienna 3.0 V6 engine is indeed an interference engine. Which is the correct information? Someone posted here that they had changed the timing belt out and found it to be a non-interference engine. That is helpful to me and others that will read this post, but if using the Gates website you will get contradictory information.
I attached the PDF doc to this reply.
http://www…r=brochure
Gates very easily contradicts itself. If you go through the website to ask whether its an interference engine, it is not indicated as one. If you look in the Gates Guide - pdf version down-loadable from the Gates site it indicates that it is an interference application.
They have the same problem/contradiction in reverse for my '97 Escort. So I’m beginning to believe it is a common problem.
So what you are really saying is not that the Gates guide contradicts itself, but the Gates guide contradicts what someone else here posted.
Just changing your timing belt will not tell you if it is an interference engine. If you really want to you can hold the cam so that an intake valve if fully open (any one will do) and while making sure the cam doesn’t move crank the engine using the starter, and see if the valve gets bent. Now would you do that? of course not. Me personally would believe the Gates guide. But then again I treat all timing belt engines as an interference engine and change the belt on or before the specified time, that way I avoid the issue completely.
The Gates website has an application where you can input your vehicle details and it will display particular details regarding the belts, tensioners, etc on the vehicle. It also states that if the engine is an interference one that it will be noted in the comments column. For the 99 Sienna it is not listed as an interference engine, but when you look up the Sienna in the Replacement Guide it is designated as an interference engine. 2 different designations from the same company (Gates). I don’t know for sure what type engine it is, but I think it must be one or the other. I suppose Toyota could have used 2 different versions of the engine, but I am doubting that. My findings contradict someone, I just don’t know who.
The Gate guides contradict themselves in exactly the same way regarding my 2004 PT Cruiser so I sent gates an email and asked them about the conflict. The reply I received was that my valves would not hit my pistons, but my valves could hit each other if the engine was at high rpm when the belt broke