Newes300

Holle folks, my es300 makes weird noise when accelerating from stop still or (1st and 2nd gears).
​​​​​​
it sounds exactly like this YouTube video
https://youtu.be/3O9_zMqQ6-M

Nad1370

Im really hoping its just a loose exhaust shield.

But it sounds like marbles in a can.
Dont want to say it but it maybe detonation/spark knock.
Especially if its happening in the lower gears under load.
Quick step to rule it out (hoping) is run the gas close to empty and fill with premium gas.

Newes300

Thank you for the suggestion! I'm using 89 octane in my car. I'll try premium after I empty the tank.

HomerJay

Also check the torque strut mount, I experienced a similar noise when my failed.
https://www.rockauto.com/en/catalog/...rut+mount,5556

koreywill

+1 on HomerJay's response! I had the same noise, replaced the passenger side upper motor mount (aka torque strut mount), and the noise was gone. As I pulled the mount pieces fell out.

Newes300

Thank you all for help out. My gas tank will empty soon. If premium gas won't get rid of the noise, I'd go replacing the motor mount.

SixString7

Hey mine is making this exact noise right now and I can see that the torque mount is broken. Its been this way for the past few years and my guess is that its finally giving out to the fullest. I actually have the part already so it might be time to install it

koreywill

Save yourself the price of a full tank of expensive gas. Look at the rubber in the dog bone and see if it's deteriorated. It's very easy to replace if it's the culprit. 15" max. On my 2003 ES it was p/n 12363-20120. Go with OEM. It'll be worth it in the long run. Take a close look at all your other mounts, too.

SixString7

So I replaced that and its still doing it. Literally just started the other day after I put a half tank of gas in. It keeps putting out code P0128, planning on replacing the thermostat real soon. Its so subtle you almost cant hear the noise, but I notice things before they get real bad.

koreywill

Can't imagine that a low temperature of the coolant would create any noise at all (possibly pre-ignition), but if you're seeing a low temp and the thermostat has never been changed, then, by all means, go ahead and change it. Please use an OEM thermostat. You'll be glad you did. If you're getting a code P0128 and the coolant is low teimp that might, (and I don't know for sure), present a preignition knock. Just be prepared for a lot of parts to yank out and reinstall. While you're in there you might as well replace the well hidden hose, water by=pass, NO.1 (1626120010 on my 2003 es300). It's subject to high temperature and, heck, you're already there (mostly) so why not? You've got a lot of parts to take out on your way to the thermostat so make sure that you get everything back as it was.
Let us know how it goes and good luck.

HOSE, WATER BY-PASS, NO.1

Genuine Toyota (1626120010)

SixString7

Thank you so much for the advice. I searched the part number you listed and every site is saying it doesnt fit on 2003 Lexus ES300? EDIT: I Found one on Amazon that says Lexus OEM and nothing at all is different, just says its guaranteed to fit and costs about 2$ more. I believe I have the same model as you do, any advice for where I can purchase an OEM Thermostat? I did not like the reviews on the aftermarket thermostats. The torque mount was not OEM, but I can certainly feel an improvement with it installed. The OEM torque mount was deteriorating and had cracks all the way through. I do not drive very much, maybe 10k miles a year max. I mainly use this vehicle for groceries and doctor appointments, as well as transport to school for my child. I really want to replace that hose while Im in there

LeX2K

This says it fits

Thermostat is 90916-A3003 consider getting it at a local dealer many fake parts out there. Reviews claim this is a genuine part

SixString7

So the thermostat is on the drivers side of the engine, correct? At that point ill have the airbox and a lot of hoses removed. How much further do I need to go to get to the water bypass hose? I cant find a whole lot of info for the v6 es300's

LeX2K

Bypass hose is under the plenum and intake a fairly extensive job. There are plenty of vids on YT any car with the 1MZ engine (which is many) is the general procedure you follow.

koreywill

Yes, the thermostat is on the driver's side of the engine.

This is a good video on just the thermostat replacement. It's on a 330 but everything is just about the same as on the 300: https://www.google.com/search?newwin...id:eA6YAOX1WOM

The replacement of the bypass hose is pretty involved. Here's a video for 2003 ES300: https://www.google.com/search?client...id:X0swOyx4z6c

I checked the part number at different Lexus sites and it's a good number as LeX2K indicated. I agree with getting the part from a dealer to be sure it's OEM.