You are most aware of your own situation and can probably best answer that yourself.
But if you are interested in some others opinions I'll give you my two cents worth. It is not unheard of to have a new car payment approaching $600 to $700 dollars a month these days as hard as that might be to believe. If you are going to buy a used vehicle depending on the year and condition the monthly payments can also add up very quickly to the cost of the the work you are considering to get done. Depending on your financial situation it may make sense to get the work done. If the vehicle is in good shape maybe it will last some time yet.
On the other hand if you are thinking along the lines of replacing this vehicle this is money you could apply to a new vehicle.

My advice is for you to do a cost analysis based on your situation. Find out what a replacement vehicle would cost - what would be the monthly payments etc. Then consider the condition and expense of keeping your current vehicle - the $850 for the work you are considering and other other expenses tires, alignments etc. Make a list of the pros and cons of keeping your existing vehicle and then make an informed decision on the facts you've put together. No one can do this better than yourself.

 

If the belt snaps your van will go directly to the scrap yard as it won't be worth fixing. If that happens you'll most likely need some wheels asap (unless this is a third vehicle). The cheapest you can buy a running vehicle that can pass emissions, etc. would be around $ 2k.

So: (had some fun putting this together... :grin
1. Can you live without this vehicle? If no, go to 2. If yes, go to 4
2. If the van dies, do you have $2k on hand? If no, go to 3. If yes, go to 4
3. Replace the belt. $ 700 over two years comes to $29 per month. Can't find car payments as low as that.
4. Totally up to you to take the risk, if you spend the $ 700 you know you'll never get them back. If it dies you can use those $ 700 towards another vehicle.

 

From my understanding, the pre August 2000 Sienna's have non-interference engines, after that date they are interference engines. Please someone correct me if that's wrong.
I saw someone post that they had a Sienna engine apart with the original belt and it was roughly at 250k miles and the belt was still ok.

So my understanding is that in your '98, if the belt were to break, you'd have to then decide if you want to tow it to the scrapyard or to get it fixed, but there would be no damage to the engine. If I'm right on this, I would just drive it and take my chances because my gut tells me you're more likely to get away with it than not.

 

You might be right, I wrongfully assumed all Sienna engines were interference engines.
That should make his decision even easier. Totally agree, if that is the case, keep running it.

 

I would like to get some confirmation on that though. The Sienna's after August have the variable valve timing and there's a VVT-i logo on the plastic cover on top of the engine. My understanding (again someone please correct me if I'm off on any of this) is that after August 2000 they also went to 6 ignition coils - they had 3 before. Also there's 2 drain plugs on the pre Aug'00 transmissions (one was for the differential) whereas they went to only 1 later. There was a sort of 1/2 way upgrade to the whole Sienna sometime around that time, it also involved a new grille, different tail lights and plastic headlight lenses where they had glass before that.

 

Here is a list of Toyota engines and if they are interference or non interference. This comes from an automotive website. If you have your engine identification a quick call to a competent Toyota Service center can confirm the information for the individual engine. The 1998 Sienna had a 3.0 1MZ-FE if the Toyota spec listing is accurate.

Toyota

1.5L (1A-C, 3A-C & 3E) Interference
• 1.5L (3E-E & 5E-FE) Non-Interference
• 1.6L DOHC (4A-F & 4A-FE) Non-Interference
• 1.6L DOHC (4A-GE & 4A-GZE) Non-Interference
• 1.6L SOHC Non-Interference
• 1.8L Diesel Interference
• 1.8L DOHC Gasoline Interference
1.8L 7AFE, 4AFE, 4AF – Non Interference
• 2.0L Non-Interference
• 2.2L Diesel Interference
• 2.2L Gasoline Non-Interference
• 2.4L Diesel Interference
• 2.5L Non-Interference
• 2.8L Non-Interference
• 3.0L Inline 6 (Except 1998 2JZ-GE) Non-Interference
• 3.0L Inline 6 VVT-i (1998 2JZ-GE) Interference
• 3.0L V6 Non-Interference
• 3.3L 3MZ-FE V6 W/ V VTi – Interference
• 3.4L Non-Interference
* 3.5L V-6 Non-Interference
• 4.7L Interference

 

Thanks for the info and opinions!
whew.. knowing that my engine is non interference is a big relief.. but I'm still planning to replace the timing belt by myself will definitely save me alot of money, I have some experienced doing my own maintenance and timing belt is the only thing that I'm hesitant working on. At least I will get myself prepared for the job and make sure to take my time .
I watched some youtube videos about replacing toyota's v6 timing belt and looks like I can do it.
I just need to take some time and make sure I have all the parts and tools I need. AISIN parts for timing belt will cost around $150 from amazon plus some special tools harmonic balancer puller will probably cost me $200 for everything and a weekend.
Is there anything I need more to know other than making the belt line up top dead center that will make the job easy for me.

I will post the picture of timing belt at 225k. ;-)

 

At the O'Reilly store I go to they lend (for free) a lot of tools, maybe one of the parts places near you has the balancer puller you mentioned. I've done several other vehicles but not a Sienna. Often it's not the belt but the related replacement parts (idler wheels etc) that fail and you can listen with a rubber hose to see if there's any funky sounds coming from that area.

Here's some info: http://www.siennachat.com/forum/16-general-discussion/86-timing-belt-change-how.html

Usually people replace the water pump when they do the timing belt and the firewall spark plugs are difficult to access unless you have the engine somewhat apart.

 

I can only tell you that I have a 2000 Sienna with 189K miles and it is the best car I have ever owned. Still have it and have NEVER had any issues with it other than wear, like belts, tires, changing fluids, etc. When I replaced the 17 year old belts on my car, the original OEM rubber looked almost new and was pliable and not cracked. The paint still looks new; the motor runs like it just rolled off the lot; does not burn oil. After 17 years, there is not 1 rattle in the car. I hate to sound like a commercial, but... A couple of years ago when gas prices were high I decided I was going to trade it for a Prius. As I turned into the dealership there was the same 2000 Sienna I was driving up on a stand in the corner of the parking lot that had 600,000 miles written in very large red painted letters. I turned around in their parking lot and went home. Drive it until it blows up.

 

what does "interference engines" mean?

 

Hi Johnxyz,

How can i check if my car is interference or non interference?
2003 sienna, ce, v6,
3.L vvt-I

many thanks!

 

Hi Johnxyz,
How can i check if my car is interference or non interference?
2003 sienna, ce, v6,
3.L vvt-I

many thanks!

You read the list he posted.... it's right there.

what does "interference engines" mean?

The valves go up and down when they open and close, so does the pistons when the engine is running. The timing belt/chain syncs the camshaft(s) and crankshaft so the valves are always closed (up position) when the pistons get to the highest point.
Non-interference engines have enough room so the piston will never touch a valve in case the timing belt/chain breaks. On Interference engines there is not enough room, the valves can interfere with the piston if that same issue happens causing valves and piston rods to bend, pistons to break and possibly other major damage.
It's all based on how the combustion chamber, valve location and piston heads are designed.

 

what kind of rubber hose? 5/8 inch diameter from homedepot?

 

Yes, interference engines have the potential of suffering severe damage if the timing belt fails, not to say they always will. The Sienna's made after August 2000 are interference engines.

hiac, by "rubber hose", a lot of things could work. Yes, 5/8" hose from HD would work, probably 3' long would work but it's a shame to have to buy anything. I've always been able to find something, like an old car heater hose (usually 5/8" or 3/4" inside diameter), a piece of garden water hose, or even an old vacuum cleaner hose. Hold one end of the hose to one ear and the other end to whatever you want to listen to, like an alternator, ac compressor, water pump etc... to isolate a bad bearing. If you had noisy valves you might be able to identify the side it's coming from. It's a handy way to locate the source of odd sounds and just the general shape of an engine.