Timing belt health

Tiny
IMAGING
  • MEMBER
  • 2005 TOYOTA SIENNA
  • 3.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 128,000 MILES
Is there a way to determine if the timing belt, gears or even the water pump need replacing?
Sunday, November 21st, 2021 AT 10:31 AM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,799 POSTS
Hi,

It is recommended that the belt be replaced at 90K. If this is the original belt, you should replace it. If you look at the belt, it will likely have rounded edges on the clogs and could be stretched. Also, if engine coolant or oil gets on it, it should be replaced.

As far as the water pump, when they are going bad, you can usually tell by either a bearing type noise or a coolant leak from what is called the weep hole. Take a look through this link.

https://www.2carpros.com/articles/symptoms-of-a-bad-water-pump

On this vehicle, the pump is driven by the timing belt, so when replacing the belt, the pump should be replaced as well.

I attached the procedure for replacing the timing belt below. Once it is off, the water pump is unbolted and removed, and replaced with a new gasket. I realize this may seem intimidating, but I'll help if you run into trouble.

One important note. This engine is called an interference engine. What that means is if the timing belt breaks, there isn't enough room between the pistons and valves and damage will occur. If that happens, in most cases it is less expensive to replace the engine. This is why I'm recommending the replacement of the belt. Also, the directions show what to check for when inspecting the belt.

Let me know if this helps or if you have other questions.
57

Take care,

Joe

See pics below.
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Sunday, November 21st, 2021 AT 8:16 PM

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