JLex23

Anyone experience a slight clunk feeling from dead stop under more aggressive acceleration...my 14 250 AWD has done this on 3 or 4 occasions. Just wondered if anyone else has felt it.

JLex23

Also it seems to occur only when accelerating from stop into turns.

UpSideDown

Turn off the traction control and try it again.

spwolf

better not most likely :-)

flippd

You sure there isn't anything in the trunk that's not tied down?

JLex23

That's originally what I thought it was...but everything I had in my trunk was in the exact position I put it in when I left, so it's not that...but that's the sensation you get when it happens

corradoMR2

Did you double-check the jack and tire replacement equipment is tight (or just remove it for testing)? Have you tried to reproduce it from a rolling start instead of a dead stop?

I'll be getting mine in two weeks so can't comment/confirm just yet but I never had this noise with my '08 250 AWD.

JLex23

Haven't checked jack or spare. It's only happened a few times in the 500 miles I've put on the car. I might check the spare to see if its loose.

JLex23

Just checked both and everything is snug.

JLex23

Well guys gotta take the IS in tomorrow for the clunk or thump when accelerating hard from a stop on what only appears to be left turns. Sucks since this car has less than 600 miles but I don't think it's normal behavior. Thought it was my spare since nothing is in the trunk but I can clearly feel it under the car and my spare is tight.

Some have said it may be the trac control kicking in but it's not a loss of power, but rather mechanical in nature. Hope my car does not need major repairs already...tearing apart a new ride, while under warranty still makes me sick. I'll keep you all posted...anyone else experience anything similar??

corradoMR2

This might be a stretch, but could be something with the hand (foot) brake? Another poster talked about a clunk and it turns out it's the parking brake cable as it was a similar issue with the 2IS. The fix seems to be that you need to use the foot brake a couple times when parked and release it, then noise is gone. It's one of the first things I'll be doing tomorrow before I drive off from the dealer lot when I get my car. Give it a shot, you never know...

JLex23

I am definitely going to try this but it likely won't rectify the issue before tomorrow morning, so I'll test it out when I get the car back. Car drives beautifully aside from clunk feeling and noise and it does not do it under light acceleration, so I'm hoping its an easy fix. The fact that no one else has experienced this makes me a little nervous. Saying my prayers tonight it isn't a drive shaft or transmission issue.

spwolf

VSC works by applying brakes... you will hear clunk when brakes are activated.

since you are saying you are only hearing when accelerating hard in corners, then i would guess it is it... otherwise things that happen during hard acceleration would also happen when you brake (something loose).

corradoMR2

Odds are very much in your favor (thousands to one) it's not a major mechanical issue. Regardless, if the foot brake trick doesn't do it or it's not the VSC kicking in as Spywolf suggests, relax, Lexus will take care of you and the car!

JLex23

Valid points for sure guys!!! I'll keep you posted for sure after I hear back tomorrow. My dealership is great so I expect that they will make sure everything is legit.