1999 Toyota Sienna LE thermostat location? - Toyota Sienna Forum - siennachat.com
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post #1 of 4 (permalink) Old 09-24-2010, 11:15 PM Thread Starter
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1999 Toyota Sienna LE thermostat location?

I have a 1999 Toyota Sienna LE (6 cyl)

Where is the thermostat located? How hard is it to get to (how may bolts to remove, etc)? Should I change the thermo with the hoses and new coolant? Do you really need a Genuine Toyota thermostat or will the friendly auto parts version due?
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post #2 of 4 (permalink) Old 09-25-2010, 04:20 PM
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Re: 1999 Toyota Sienna LE thermostat location?


Here is a link to the components for the thermostat

Here is the link for the removal of the thermostat.

The link to the whole user manual is right here

Are you sure you need to replace the thermostat? What are your issues? Over heating?

Regards, Jason.

1998 Sienna XLE Silver Spruce Metallic
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post #3 of 4 (permalink) Old 09-26-2010, 02:50 PM
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Re: 1999 Toyota Sienna LE thermostat location?

Buy a Toyota thermostat, and replace them at around 100,000 miles or 5 years. Brand X may or may not be as durable, and there is such a thing as false economy. Some say the Toyota thermostats never need replaced, but I talked to an engine rebuilder who says he sometimes gets Toyota heads to rebuild or replace, somewhere around 150,000 miles, because of bad thermostats.

For a number of reasons, it is not always a good idea to wait until a part fails to replace it, and a thermostat is the best example I can think of, because you just blew $2,000 in repairs when that sucker breaks.

Keep good coolant in the cooling system. It won't break you.
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post #4 of 4 (permalink) Old 10-02-2010, 08:02 AM
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Re: 1999 Toyota Sienna LE thermostat location?

Here is a link to the first in a series of pictures of the thermostat replacement job on my 2003 which should be almost identical to what you need to do on your '99.

The "O" rings are for the tube that you need to remove and the thermostat gasket.

Your 1999 Sienna came from the factory with Toyota RED coolant, not pink.
I would recommend sticking with the red coolant.
I would also undo the Zip tie that holds the front Air / Fuel (Oxygen) sensor to the radiator hose before pulling the hose off.

wiswind is offline  

1999, location, thermostat, toyota

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