[Rav4S2K]

So I'm reading a lot on this forum on how the water pump needs to be replaced every once in awhile - intervals, how to, etc.. But no info on what it actually does.

What does the water pump do? What are the symptoms of it going bad (I've read here that it makes noise?)? What are the results of it failing?

Any info would be great - thanks.

 

[Jeff]

The water pump is an integral part of the engine, and is roughly the same on every car or truck. It is driven off the timing belt or seprentine/accessory belt, depending on the specific engine. It does exactly what its name implies- it pumps (or circulates) the engine coolant/antifeeze through the engine block, radiator, and heater core. The water pump runs the engine cooling system in the car, and without it the engine will overheat and die. The cooling system also functions as the heating system for the inside of the car.

When the pump is starting to go bad, the engine sounds like a diesel when it is idling.

 

[Rav4S2K]

The water pump is an integral part of the engine, and is roughly the same on every car or truck. It is driven off the timing belt or seprentine/accessory belt, depending on the specific engine. It does exactly what its name implies- it pumps (or circulates) the engine coolant/antifeeze through the engine block, radiator, and heater core. The water pump runs the engine cooling system in the car, and without it the engine will overheat and die. The cooling system also functions as the heating system for the inside of the car.

When the pump is starting to go bad, the engine sounds like a diesel when it is idling.

Great - thanks for the detailed explanation! I figured it circulated the coolant around the engine and such, but I wasn't quite sure since it was called a water pump (vs coolant pump, etc).

 

[Stelly]

When it starts to fail - mine anyway - it would make noise when cold, after the engine warmed up the noise would stop.
When it fails - it breaks the timing belt and you need a tow truck to take you to the shop!
I know! I replace the timing belt and like some people wanting to save money, "the water pump isn't that bad"........ a couple months later we were having it towed and replaced the timing belt again along with the water pump and idler bearings.
Unless you like to pay tow trucks and live in the fast lane of excitement, replace the water pump when your service manual says to....... I keep mine maintained and get good service out of them. I plan on getting 300,000 miles out of my 2000. So far...
'98 RAV4 with 271,000 miles
2000 RAV4 with 91,000 miles
362,000 miles total, 310,000 with my rear in the seat in less than 4 years.......... about 79,000 miles a year.
That adds up to three water pumps and four timing belts, 1,600 under the breath @%$#& words and 25 skinned knuckles!

 

[michaelp95]

Mine sounded like someone put rocks or marbles in the engine when it was cold. I had mine changed at about 88,000 miles, the noise first started like 79-80,000 miles. I only had the timing belt and water pump changed. The forums weren't opened back up here, so I said nothing about them changing out the idler pulleys, is that something that they would inspect and change out if it was bad or going bad? There was no mention of it on the invoice when I picked it up. I wish I would have known about it sooner, I would hate to go another 10k miles and find out that ruined the timing belt and have to pay for another one.

 

[Rav4S2K]

How does the water pump's failure cause the timing belt to break? Now I'm starting to get concerned since I just had my belt replaced.

That's a lot of miles on your RAV - you should send in your story to Toyota. Maybe you'll get something nice out of it, in return for being featured in some advertising of theirs.

When it starts to fail - mine anyway - it would make noise when cold, after the engine warmed up the noise would stop.
When it fails - it breaks the timing belt and you need a tow truck to take you to the shop!
I know! I replace the timing belt and like some people wanting to save money, "the water pump isn't that bad"........ a couple months later we were having it towed and replaced the timing belt again along with the water pump and idler bearings.
Unless you like to pay tow trucks and live in the fast lane of excitement, replace the water pump when your service manual says to....... I keep mine maintained and get good service out of them. I plan on getting 300,000 miles out of my 2000. So far...
'98 RAV4 with 271,000 miles
2000 RAV4 with 91,000 miles
362,000 miles total, 310,000 with my rear in the seat in less than 4 years.......... about 79,000 miles a year.
That adds up to three water pumps and four timing belts, 1,600 under the breath @%$#& words and 25 skinned knuckles!

 

[Stelly]

The water pump is driven by the timing belt. If the bearings in the water pump freeze up or it gets real hard to turn the pump the timing belt just can't turn it any more and it breaks. That is what happened to mine.
As far as the idlers - you would hope they checked them. I had the tensioner idler that was really bad. They are turning at the same rpm as the engine with no lubrication (sealed bearings) so I figure I just want to change them while I have it apart.