shivnator

Dear All,

I own a 2017 Lexus IS 200t with 75,000 miles. Is it possible to damage/ mess up a water pump when replacing the drive/serpentine belt. My mechanic replaced the drive belt on Sunday. Then on Monday my car started overheating , I took it to the dealer and he said the coolant leak caused the damaged water pump. Is it coincidence or is it all related. I believe the mechanic could have installed the drive belt improperly which must have caused the cooling system to fail.

Here is what I found based on my research. One of the critical components that the serpentine belt drives is the water pump. ... If the serpentine belt breaks or even loses tension due to tensioner malfunction or even belt wear this can cause the water pump to not turn or pump the required volume of engine coolant which will in turn cause the engine to run hotter.

Any help will be appreciated?

Thanks

LeX2K

The belt which drives the water pump is auto tensioned so the only way I can see the mechanic messing this up is damaging the tensioner, or used the wrong drive belt. (or maybe put his greasy hands all over the belt?) Can't say if the water pump just happened to fail, not impossible.

kj07xk

Unless you have had a long term relationship with this mechanic, and trust him, ‘coincidences’ like that make you very suspicious.

Sasnuke

Welcome to the forum!

I think the dealer meant to say that the coolant leak from the waterpump caused the overheating.
Cooling leaking onto the waterpump won't do anything to it...and I'm assuming replacing the waterpump fixed the issue.
There are several members that reported waterpump leaks on their IS200T around the same mileage as yours, even a little less in most cases.
For a number of reasons a waterpump could start leaking, and it's not an uncommon thing...some times it's good old fashion wear and tear.
And chances are the waterpump has been leaking for some time...it's not common for a waterpump to be fine today and leak bad enough tomorrow to cause the vehicle to overheat.
The leak is usually slow and progressive, sometimes over months and even years.

Do I think your mechanic caused the leak when changing the serpentine belt? No. While not impossible, I would consider it highly improbable.
Chances are it was leaking already when he changed the belt. He either didn't see it leaking, or saw it and didn't mention it...I'd like to think it's the latter.

kj07xk

Such negativity! Or did you mean to say ‘former’?

Sasnuke

Nope...I meant latter. I mean, he could have not seen it, especially if he wasn't looking for it, but without seeing it ourselves it's hard to say.
Toyota has a long history of using Aisin waterpumps, and Aisin waterpumps have a long history of weeping/seeping coolant from the breather hose.
Toyota even has a bulletin showing pics of what is considered a 'normal' leak of the waterpump that doesn't require replacement, and what actually constitutes a leak, that does require replacement.

Having the dried cauliflower crusty around the breather hole isn't anything fantastic, but if you can actively see fresh coolant, or cooling dripping, then obviously time to replace.

E46CT

The water pump on my 2016 IS200t failed at 25,000 miles and was replaced under warranty. It was leaking.

So @ 75k miles, it's certainly possible it was on its way out. That's about the lifespan for a belt-driven water pump anyway.

shivnator

Thanks to all you guys for the responses. I am replacing my water pump tomorrow. Funny story, I got quote from two Lexus dealers in South Florida, one said $1,100 and the other (50 miles away) said $600 and Im going with the later. Too bad, the first dealership located half a mile away would not price match.

E46CT

Not super bad @ $600. you won't have to mess with it. part is probably $90 ish retail so rest is coolant and labor.

edit: yep googled it (promise i didn't look it up beforehand) and it's between $75 and $90 for the Aisin part

E46CT

Also looks like it's already a thing on youtube. heres the DIY:


looks fairly simple. lots of room to work. pop shrouds/covers/belts, then pulley, then pump. refill and bleed. voila

Chris03218

I wouldnt be suprised if your serpetine belt was going to due to a bad water pump. When one of the items that run off the serpentine belt start to fall usually theyll eat the belt up.

SentinelCipher

Reviving a bit of a dead thread, but just wanted to say my 2016 IS200t just hit 90k. 2 days ago I started hearing a whine (sounded like belt whine) coming from the engine bay. I parked the car at home, and took it to the mechanic the following morning. Mechanic said "it's the water pump, it's probably fine for a little bit as long as you don't mind the noise." I ordered a water pump online while I was sitting at the mechanic (they were doing a brake job). On my way home from the mechanic, which was less than 2 miles from my house, the water pump grenaded and the temps shot up, dumping coolant all over the road. Needless to say, the car got towed to my mechanic and I am now getting a new water pump. Less than 24 hours of warning, so yes, it definitely can happen suddenly. The sound after it failed was atrocious, but I stopped right away so it didn't actually get the chance to overheat. Car just decided it didn't want to wait a couple days for the pump to arrive. I get a 2008 IS-F and the valley plate leaked coolant, now I get a 2016 IS200t and the water pump fails in a spectacular fashion. Lexus and cooling systems, the reliability of everything else is great, but those cooling systems...