Hey guys. I decided to buy a new water pump since my car is at the mileage where it's recommended to be replaced -- currently at 76,000+miles. I bought the Aisin water pump off ebay ($110) which came with it's applicable seals/gaskets.
My mechanic mentioned I should [would need] to also get a new thermostat and seals for the thermostat housing. Is this also another component needed for this job? His reasoning is because of the work which needs to be done involves removing the thermostat and was weary of using an older thermostat and housing when putting everything back. Anybody here familiar with this process, what it entails and if what I mentioned is actually necessary?

Thank you!!

 

Thermostat, serpentine belt, idler pulley, and 2 jugs of toyota pre diluted coolant. These are the things I would replace! The job took me 2hrs maybe and its fairly easy for a decent mechanic.

Ive had my Aisin installed for 3 years with no issues.

 

Thanks for the quick reply! The fluid my mechanic will handle. The idler pulley is another part I assume I have to purchase in conjunction with the thermostat?

As a sidenote: What I am hearing is an almost rattling sound. Goes away after the car has been warm for some time. Is there any symptom or telling sign if the water pump if failing? Does a check engine light pop up? So far I have nothing displayed on my instrument gauge to decipher anything wrong with the car.

Given the water pump/damaged engine horror stories I've read I am hoping to avoid a similar snafu

 

You can reach behind the water pump pulley and feel for pink foam. That foam will be coolant leakage

Rattling sounds like maybe idler pulley going bad. Yes I would buy the idler pulley, and serp belt. Look on ebay for dayco serpentine belt (its oem brand) idler I think I used koyo brand.

 

Where exactly is the water pump located? I've seen diagrams but when actually looking under the hood I think I may have incorrectly assumed where the water pump is located. On the sheet metal at the bottom of the engine bay there isn't any liquid or pink residue to show any leaking fluid. I assumed the water pump was the part at the front of the engine towards the bottom closer to the driver's side of the car -- looks like a oddly shaped cylindrical piece in a silver color (doesn't resemble the water pump at all lol). Unless that's the alternator and I've been looking at the wrong section this entire time

Upon closer listening last night it did sound more like a pulley/belt wearing since it would subside after some time -- I assume due to any oil/lube getting worked around the belt.

 

Spoiler alert, i have 173k on my orignal water pump and its working fine. Only changed my thermostat within the cooling system while i was changing my timing belt, got lazy and decided to not to change it. I do have a replacement on standby that i purchased back in 2013.

 

Oh and that rattling sound is definitely your serpentine "accessory belt" i changed mine 2x times already, sprayed a little belt dressing and no more issues. Most Toyota OEM parts are far superior than domestics, you'll be suprised how much mileage you can get out of your OEM's

 

i agree with this. When I had my 06gs300 some coolant fell onto the belt and it would make that same noise you described when the car was cold. After I changed the belt it went away.

 

This problem is mainly on the GS350's

 

Assuming you have a GS350:

I replaced my water pump when it failed at around 90,000 miles, and also replaced the belt and idler pulley, but did not replace the thermostat.

 

Thanka for the replies guys. Put me at ease knowing I'm not necessarily staring a blown engine in the near future. The pulley is most likely the culprit for the noise and will get it inspected and fixed if so.

I have a 2008 GS350 by the way. Realize I didn't mention it in my original post. I'll update this thread once I get my car looked at

 

Also the variable cam can make a rattling noise when cold. You can isolate the noise by taking off the drive belt and running the engine for a short time when cold to see if the noise goes away, that way you know its one of the pulleys/ idler or internal. Hope this help

 

If I've had the car running for a while the noise eventually subsides -- albeit to a lower decibel sometimes or altogether.

On the topic of the water pump: Are there any telling signs aside from fluid leak? Does the instrument panel display a message in the message center, or a check engine light? Basically any heads up prior to full blown engine pandamonium? lol

 

U will be losing coolant level if your pump is leaking... Plus coolant residue below the pump

 

My water pump failed last winter when I was about 15 miles from home – I could tell because the heater was set to 77, but began intermittently blowing out very cold air. A few hours after I got home, I went back into the garage and found a large pool of pinkish-red fluid under the car.