WBenz

Hello guys...
recently my 17' GS350 AWD start making weird grinding like noise while being at idle and when moving at slow speed. Does any body know what it is? Is this ? I took the belt off and tried the idler pulley , it does have some play .. but I can't believe it will make this kind of noise ?

https://youtube.com/shorts/vXk7y3ejG_8?feature=shared

bclexus

You might want to have the MAF sensor cleaned. A dirty MAF sensor can cause surging, especially at idle or with slight throttle opening.

WBenz

Will try that..thank you
does any Maf cleaner will ok?

WBenz

Just did ... but it's still the same

tammap

Sounds like a bad tensioner or waterpump!

If you are handy, remove the serpentine belt and hand spin the belt tensioner and the waterpump pulley. If you feel binding, grinding or dragging, then you know which part is bad.

bclexus

Yes, all the MAF sensor cleaners are about the same - one is as good as any of the others. I personally would probably choose CRC brand but it really makes do difference.

WBenz

I bought stethoscope and was able to locate ..I think .. both idler puller and water pump housing ha sthis sound ..
Now a year ago or more I had a leak a pink fluid on low bay of a engien.. Antifreeze and my coolant level was way below .. I added and since then I never have problem..
hmm could water pump be a problem I don't know..
Btw also I took belt off again and ate pump pulley has a good play .. but when I try to spinning it doesn't give me that " metallic sound ".. but it has play ..
Maybe will give car to Toyota dealer... to check

bclexus

There's a lot of stuff rotating round-'n-round and going up-'n-down when an engine is running, including stuff like fuel injector solenoids rapidly firing.

Even a leaky or shorted diode in the alternator diode bridge can sing (screech) really, really loud from inside the alternator housing as it allows current to leak from the battery back through the alternator to ground. This screeching sound is often mistaken for a bad pulley or slipping belt. You also have a VVT (variable valve timing) system that can make a harsh metallic ratcheting sound with varying degrees of engine oil pressure. It all makes noises!

The thing to remember is - you can check things all you want, but most parts work until they don't!

At the time a part no longer works, that is when its time to replace it... Even when an experienced mechanic says; "everything looks good", what he means is - all parts appeared to be working when I checked them....

WBenz

Thank you 😊

WBenz

OK .. Independent shop called and said it's a Waterpump. As I afraid..
Is it hard to replace a Waterpump?

bclexus

@WBenz - Be aware that a water pump - even a brand spanking new one - will make a mechanical noise because the internal impeller is rotating. Most water pumps will leak at the seal as an indicator it needs to be replaced. That said, if it is not leaking there is no substantial or meaningful reason to replace it. Chances are - if you have it replaced you will hear the same sound from a brand new one..

I don't know what the Indy shop mechanic did to determine this specific sound (that seems to bother you) is expressly coming from only the water pump, but if he used a long screw driver or bar placed on various parts and listened with his ear to the handle, or used a stethoscope to listen - - a noise is produced by literally every single part that moves (and some things that don't even move like diodes in an alternator. But with things such as an alternator, compressor, etc. - these items produce sounds that are not necessarily smooth sounds - they are often rough, grinding or whirling sounds. Additionally, sounds from one mechanical automobile part easily travels to other parts because they are usually bolted together in some all-encompassing fashion instead of isolated from one another, so it's very difficult to segregate one sound producing part from another...

Unless the water pump is leaking - as long as the coolant is keeping the engine at typical operating temperature - there is no sense whatsoever in replacing it.

As I have said; you can check things all you want, but most parts work until they don't!

It's usually a wise decision not to replace a part that is still working and sound! (excuse the pun)

WBenz

I just got Instructions manual for water pump removal from Lexus tech and it seems I have to remove A/C compressor and lines and oil housing and have to recharge the system.
Does anybody done this ? Anyhow to bypass that removing AC ?

jgscott

iTrader: (1)

You may want to call a Dealer or Lexus and give them your Vin#. I think I remember there being a free Customer support due to faulty water pumps on some later year GS's.

EAST

Yea that's what has stopped me from replacing mine.

It showed red a couple times, but it might just be as Lexus say and the pump was just clearing some debris from a weep hole, since it hasn't come back. The TSB specifically requires the leak to be ongoing before they'll cover it.

I wonder if it's possible to remove the compressor enough to access the needed bolt, then put the compressor back on without disconnecting it.

WBenz

I let the shop do it. They charge me 1850$ . I live In Upper NY state ..
Will pick tomorrow car.
Btw our Lexus been in shops more then my w210 Benz.. we bought Lexus brand new in 2017. Idk why Lexus has bad things.. it's makes me confuse
​​in the past AC were broken also...
So anyway thank you guys so much for your input .
i appreciate for repsonses.