Ab423

I have a 2007 IS350 with 67,800 miles and just noticed a knocking noise one night while driving into my driveway with my window down and since I park in between two cars I can hear everything. I know the sounds that are normal coming from this engine I also have a 08 GS350 that I've had for about a year and a half now with no issues at all . So I take it into the dealer and get it confirmed that it is coming from the lower block next to the tranny but now to go any further they were told by lexus to get another car same year and model to see if they all make that noise. My question is has anyone here had this issue and is anyone here willing to help me out that has the same car so we can take a trip to the dealer so they can see is not normal. I'm in Rhode Island and the dealer is Inskip lexus I would really appreciate it thanks

Gville350

iTrader: (10)

So did you only hear the noise when traveling on a flat surface, or were you going over a curb or something? Does it sound engine-related or suspension-related?

Ab423

Is only when the car is stopped and in gear is that I hear it

Gville350

iTrader: (10)

Ok, so can you have someone push the brake down on the car while you look for the noise outside or under the hood?

whitebeast

iTrader: (5)

he needs second car go with him to dealer. If second car not having the noise while his car does. If he could prove the other car doesn't have that noise, his car gonna get taken care under warranty.

clubfoot

It could be a cracked flex plate. The torque converter attaches to the flex plate that has the starter ring rear. If it develops a crack it can sound like a lower engine bearing knock.

Of course it could also be the "normal" engine knock of the IS. Make a video let's hear it.

tonnetje

i have the same sound
only when motor is hot and in gear with foot on the brake
its just only by 600rpm in drive or reverse
symptoms perhaps
low oilpressure?
to thin motoroil ?
or something from the torque converter /lowoil level in AT?
keep us posted
its like of its comes from the end of the engine/front tranny
its no exhaust ratlle
next weekend i post a soundclip
greetz

clubfoot

^^Yea what he said, very noticeable in a drive through close to the wall.

Ab423

The car has been at the dealer for almost 2 weeks now they're just waiting to get one in for service but these car are not to common up here in the northeast.

chris07is

iTrader: (10)

ive been having this knock for a long time sometimes when windows down, i can hear the knock from the transmission when it change gears (automatic), especially going to low gear. Its actually louder when going on Reverse as well. i was thinking that its the transmission, but my car is 07 with 120K. the car still runs excellent.