If I goose it from a stop there is a very noticeable thud. What is strange though is that's the only time it does it. Normal throttle from a stop is fine, no issues. Shifts fine, no vibration in wheel or shifter, etc. If I hold the brake and give it gas it thuds then too.

I'm pretty sure it's a bad motor mount. How much am I looking at?

 

Maybe around $300 to have it done? or: https://www.clublexus.com/forums/ls-...acement-2.html

 

Put your car in drive with foot on brake. Keep your foot on brake while giving it gas. Have someone do this as you are looking in engine comp. Is the engine lifting or shifting position when giving it gas. Do the same thing in Reverse with foot on brake. Excessive movement of engine up and down is sign of bad motor mounts.

 

Yeah, I haven't gotten to that yet. But thanks to all of your for the advice. I don't see what else it could possibly be. I'm not a mechanic but I know a lot about these cars like mechanics do.

I'm not worried about it bc it only does it if I were to really gas it from a stop, will have them checked at next oil change. Luckily there's a great Lexus indy shop in town!

 

It may look something like this one if bad mounts:

 

When you do Bocatrip's suggestion, do not stand in front of the car, stand to the side.

 

LOL thanks for the tip. I literally was just thinking I'd get myself run over haha.

 

Be careful with letting it go too long, the mounts on these cars like many Japanese ones do not have a "safety" setup like US cars do. If they break all the way the engine is free free, not still restricted from leaving the car like in a US car.

 

Thanks for another tip. I'm not terribly worried about it at this time, as it only does it if I give it lots of gas from a dead stop, which I never really do. Full throttle from 30 MPH, the downshift into first and ensuing upshift into second are still butter smooth. I figure if it were really bad I'd have some rough shifting.

I figure if it were at the point of no return I would notice other symptoms. None as of yet. I'll have it checked next oil change or tire rotation.

 

For many years on this forum I haven’t heard very much on defective motor mounts. I guess with enough time and miles anything can get worn out.

 

Boca's right we rarely hear of them failing, prob 9/10 replacing the transmission (aka rear mount) solves the problem. It's a good place to start as it's cheaper and WAY easier to replace.👍

 

If the car has been driven really hard (i.e. flooring it from every stop light all day ever day) then the motor mounts will wear out.

 

I'm starting to think that, too, that it could be a transmission mount. I can tell it's coming from the rear of the engine bay.

 

Kind of a quick and dirty diagnosis method- next time you're stopped at a stop light, or sign, and feel a little vibration just slip the trans into neutral for a few seconds. If the vibration goes away good chance it's the trans mount.

 

There is no vibration or any abnormal behavior...yet. Just the thud if you goose it from a stop, which I never do unless I have to.

Thanks for everyones responses I will keep this updated!