Hello all. I’m a happy owner of an 09 GS350. Relatively low miles(43xxx). There is a whine sound in the engine bay.
I can hear it slightly with the windows down, and the whine is more noticeable under acceleration.
Any suggestions on the cause of the sound?

 

Typo… engine *whine*

 

pop open the hood, grab wd40 if its an idler pulley that making the noise spray directly on the bearing and try to avoid the serpentine belt as it may make it slip for a min. if the noise goes away then you will need to replace that pulley. Its possible it is coming from the water pump if you have never replaced that, then its best to replace it with oem or aisin brand.

 

i have the same noise, i thought the whine was normal. only happens during accel.

 

You shouldnt have any whinning something wrong if you do. If its a water pump going bad or leaking, then that can destroy your engine. If its just a simple idler pulley or tensioner then thats fine, and simple to replace

 

First things first, if you haven't already, go ahead and order a new belt. While you have that off, you can pull the tensioner and idler pulleys and see if something is going on there. BEFORE you do the belt, loosen the 4 12mm bolts on the water pump pulley (you will be using the tension on the belt to hold the pulley so you can loosen the bolts). When you remove the belt you can take the water pump pulley off and check the bearings/play in that pulley and look for pink crusty/liquid visual signs of leakage.

I JUST did my water pump replacement over the weekend. I have a ton of pics. Quite easy to do everything I just mentioned above. Just in case, from my notes, here are part numbers and prices from my Amazon order:

7/20/2021 Ordered Serpentine Engine Drive Belt Amazon $12.03 Bando USA 7PK1550 Serpentine Belt (makes Toyota/Lexus OEM belts) $12.03

07/21/21 Ordered via Amazon:
AISIN WPT-137 New OEM Water Pump Kit $116.89
Permatex 22071 Water Pump and Thermostat RTV Silicone Gasket, 0.5 oz., 0.5 Ounce
Loctite Heavy Duty Threadlocker, 0.2 oz, Blue 242, Single $12.26 (both)
AISIN THT-004 Thermostat with Housing $28.08

Let me know if you need pulleys information.

One last thing to consider, if you are comfortable with this: some people are unsealing their pulley bearings and re-greasing them. I would try that myself but my problem was the water pump. There are YouTube videos and write ups on re-greasing sealed bearings.

Oh, I have a 2008 GS350 RWD. Just FYI.

 

Aisin water pumps on rockauto are a bit cheaper at $87

 

Yes. I actually got it for $88.57 shipped (price adjustment). It was just further down in my notes.

 

my water pump was replaced at 65kmiles im at 113k. maybe its going out again? ill take a look today since im off.

 

I bought my 08 at the end of May. It had only 54K miles on it, but by 55.5K it was evident a water pump was due. And the car was babied by the previous one owner. All service records through her local dealership. My point? 55K miles is all it took to kill the original water pump, albeit over 13 years....

 

And by the way, my noise was a rattle. towards the end it was a slight screech at startup, then it became a constant screech and I stopped driving it until the replacement. I never had a "whine."