Greg5OH

hello, i notice i have a slight vibration thru the cabin when free revving the engine slowly at the rpms listed. smooth as silk at other revs.
Now-the car is not stock, the exhaust has been cut to be tucked up flush with the frame rails and the front mufflers were removed, and in doing so-the big dampers near the front cats were eliminated. Wondering if the vibration is jsut resonance as a result of this?
What else can I check out before ruling it is the exhaust?

plugs and coils have approx 30k miles on them. oem densos.

Finn

Engine mounts?

Greg5OH

how can i make sure its the engine moutns? Car has 115k miles or 194kms

LScowboyLS

I agree, replace 3 engine mounts (one is commonly called the transmission mount)

these mounts are extremely well made and liquid filled, do not use aftermarket

they go bad after 15 years or so, especially if the car has endured temps below 0

Greg5OH

gah...really didnt want to hear that but most likely the case motor mounts are never much fun.
Im scared i cant jack my engine up very much since the exhaust is tucked up very close to the body.
The cross member can be dropped down though if the engine is supported right?

LScowboyLS

your LS400's exhaust is no more tucked up than anyone else's 2000 LS400!

why not start with the $40 transmission mount, that might do the trick by itself, and it is super-easy to install

just MAKE SURE you get the real Toyota part, not some aftermarket crap off ebay

part number - 12371-50060 ---> $39.72 with our discount at Sewell Lexus

the two main motor mounts are part number - 12361-50101 ---> $95.33 each with our discount at Sewell Lexus

MyLparts

12371-50060 $39.00
12361-50101 $95.18
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Use CL5 for ClubLlexus discount
www.MyLparts.com
Factory Lexus parts

AtlasLS400

iTrader: (1)

I'm 99% sure it's the engine mounts. Mine did the same thing at those same rpms. If the exhaust was the issue it would be an isolated noise. There is no mistaking that harmonic vibration that bad engine mounts cause. While your at it check your trans mount.

black_LS

A new transmission mount fixed this issue for me.

I replaced the engine mounts shortly after, as well.

Tip: make sure to unbolt the heater control valve from the firewall before you jack up the engine when doing the engine mounts.

Greg5OH

my exhaust is cut up and rewelded to be tucked by the floor, its in the same plane as the frame rails. Not much room between it and the floor.

Sc0pe

iTrader: (1)

You might want to take a look at this...

Greg5OH

Yup that is (now) my car.
Ordering the tranny mount regardless, and trunk seal as i just notice it leaks in the heavy rain yesterday. Wet around the top face seal.

Greg5OH

new tranny mount ordered, will replace next week see if it helps

jnew911

I'd like to know if it helps. I have vibration too.

Greg5OH

can anyone confirm if I can drop the whole engine subframe while supporting the engine, to make the motor mounts easier to put in? Like I said, i dont have much room to lift the engine up.