sik96ls400

I've had this issue for a while and I searched for it. When I first start the car, I get this "thump" or slight shake from the engine. It happens in the morning, or anytime I haven't started the car for a while. I'll get a "clunk" from the hood. If I start it again shortly after, it won't happen. I did a search for it, someone may have had the same problem and they mentioned "tranny mount". So I just had the tranny mount changed yesterday and later that night, same "clunk". This morning once again, same clunk. Anybody knows what this problem may be? I don't want to keep spending money for the wrong parts. Its a 96 with 160K on it, but its had this problem for a while now, probably since I had 130K. I had 2 other LS400's before and never heard that same "clunk" in those cars. Any help will be appreciated. Thanks

deanshark

This topic, clunk & thump, has been talked about alot. I wouldn't say 100% but it's almost deffinately your motor mounts, especially with that many miles on them. I've heard of them going with alot less miles, mine for one instance. You can check them by putting your car in drive, and reverse, and with foot on brake give it a little gas and see if the engine jumps a bit. It shouldn't move. Here's a link on how to change them.
https://www.clublexus.com/forums/ls4...placement.html
How bad was the tranny mount you changed yesterday? I'll bet it wasn't too good. If it was real bad then the motor mounts are probably just as bad b/c if one is bad it puts more stress on the rest. Even if they look good it doesn't mean they are.

sik96ls400

tranny mount was broken. bad shape.

sik96ls400

Looks like its the motor mounts. I pressed the foot on brake, going reverse its fine...but on drive, there was a thump when I really pressed on it. if I just tapped it, it was ok. but when I pressed on the gas, it clunked. seems like I'll change those next.

thanks

deanshark

Have fun. The link I posted is for a 93 I think but it should be pretty much the same thing as 96. I know there's some more tutorials around if you search for them. I think the drivers side is harder to get to then the passenger side.