Toyota Sienna XLE Water Pump and Timing Belt

Gurrent mileage is 88140. I have been told by my local dealership that it is way beyond time for me to have replaced both of these and that should the timing belt break it could do serious damage because it is metal which to me makes it a timing chain and not belt? Regardless,I wanted to ask the forum before I consider spending the big bucks they are quoting me.


What year model is your Sienna ?

Second opinion is the key word here.

What year is your Sienna?

Need to know the year and engine. Some used timing belts and some used timing chains.

If your Sienna is older, it probably has the 1MZ-FE V6 or 3MZ-FE V6, both of which use a timing belt

The 1MZ-FE is non-interference, according to my source

The 3MZ-FE is interference, according to my source

My 2005 has the interference engine, the owners manual specifies to replace the belt at 90,000 miles or 9 years whichever occurs first. I replaced mine at 9 years with 70, 000. it still appeared in very good condition (which may be deceiving), I did not replace the water pump or cam seals. I’ve heard many people have gone 120,000 before replacing the belt, how’s your luck? If it breaks you will have major damage to the pistons and valves.

To the best of my knowledge my 2006 Sienna with a 3.3 V6 was the last year with a timing belt. The change interval is 7 yr/90k miles whichever comes first. I paid 1k for timing belt, water pump, and tensioner replacement. It would have been 200 more to replace the cam seals. The 3.5 V6 in the 2007 has a timing chain.

Sorry for the important information. My vehicle is a 2004 model with a 3.3 L V6.

You have a timing belt. Replacement interval is 90,000 miles or 7 years, whichever comes first. If you still have your owner’s manual or maintenance manual, this information should be included. You have eclipsed the mileage requirement on the timing belt, and should get it done ASAP. Next week is not too soon. The water pump is not nearly as critical, but since the timing belt has to come off for the pump, you should get them both done at the same time.


Thanks for the information

You have the 3MZ-FE engine . . . definitely an interference engine

You are overdue

Here is what I recommend replacing, all at the same time

timing belt
cam seals
front crankshaft seals
water pump

Bottom line . . . you want EVERYTHING under that timing cover to be new, and good to go until the next time

A dealership shop isn’t required for this job. This is a common maintenance job and most any experienced mechanic has done it many times before. It will probably cost considerably less $$ to use a well-recommended (by friends, family, co-workers etc) inde shop.

If OP simply cannot afford to have all that work done, but can afford to just replace the timing belt, as long as the other components are checked and pass muster, only replacing the belt and leaving everything else as it be is much less risky to the OP’s wallet than doing nothing.

For this vehicle you will find that removal of the engine bracket will likely cause it to crack. Figure it will cost another $100 or more to replace on top of the cost of the timing belt and any other items you replace. I too recommend that you replace the water pump and idler pulley. Good luck.

The OP could certainly replace the belt only but that’s not a good move and especially so with an interference engine.

I can’t check a water pump or idler/tensioner bearing and say for certain it will last even another month. It may feel fine in hand at that moment in time but once a bearing or bushing starts nearing the end it can meet the end very quickly.
The same goes for the belt itself. A belt can appear to be as new and may break the following week.

Get at least 3 quotes, including the dealer. The dealer had the best price for the timing belt replacement on my Accord. Make sure the quotes are detailed so that you can compare them properly. They should all replace the same things. The minimum is the timing belt, water pump, coolant, and serpentine belt. You can ask for the additional cost for replacing the rest of the equipment mentioned above.

I think you’re asking for trouble if you don’t replace everything

Any of the items under the cover can look fine today and fail a week later

Don’t know where you get the info that the belt should be changed at 7 years, my owners manual says 90,000 miles or 108 months, according to my old fashioned math that equates to 9 years! I don’t do common core math.

I realize you guys are convinced the whole mess should be replaced while he is in there. But, you also complain about owners who do not read the car manuals. My 2002 Sienna specifically says in the shop manual to INSPECT those items when the timing belt is replaced. Dealers are not noted for passing up possible work, and their mechanics told me the same thing. The first time, they inspected it all, and just replaced the timing belt. The second time, they inspected it, and said it needed to be replaced, so I did.

You can’t have it both ways. Complain at owners for not reading their manuals. Then, turning around and tell them to ignore the manual on something else.

108/12 == 9 years, you are absolutely right about that. The experts here are providing a commonly expressed rule of thumb for timing belt life expectancy (in time) of 6-7 years. I doubt anybody looked up the manufacturer’s recommendation intervals for the OP’s make/model/year. When in doubt, if you go by what the owners manual says and use OEM parts, that should be good.

The owner’s manual is all about physical fitness of the components, not about labor cost. A timing belt job is most labor, so you replace all that’s inside that cover for an extra $50 or so when you do a $800-$900 timing belt job.