celsior123

I have got a 1998 LS400 and on initial start up you can feel the engine rock/sway the car sideways (very minor sway) . Like you see on those V8 muscle cars. Just wondering if anyone felt the same as me.

sha4000

iTrader: (1)

Mines shakes a little but I believe it's bcuz either my cam/cranks seals are leaking. Might be your engine mounts though. The LS should not sway on start up.

Turbosauce

iTrader: (1)

My 98 doesn't sway on startup, possibly your motor mounts are shot.

timmy0tool

iTrader: (7)

you shouldn't feel anything. do you recall the champagne glass commercial? your motor and/or transmission mounts probably need replacing.

Tortuga

My 97 LS used to sway on startup, but then I replaced the engine and transmission mounts, and now it's totally steady.

RA40

iTrader: (6)

How many miles on car? The engine and tranny mounts are due on pretty much all these cars now. Those replaced, it will be well dampened and not move. If you also have gear selector vibration, that is another symptom of a worn mount/s.

PureDrifter

iTrader: (10)

dead motor mounts, mine does that too.

celsior123

My car is a japanese spec Celsior has 95000 Kms. And my gear shifter doesn't vibrate that much, only very minor when I stop at the lights. Is that normal or should it be dead steady? Same goes with my steering wheel

celsior123

Sometimes there is a thump sounds right when engine fires to life as well. How much will it cost to replace the mounts?

PureDrifter

iTrader: (10)

mounts in parts is about $400-500 iirc, maybe a bit more, labor is ~$350-650.

Pricing in USD.

sha4000

iTrader: (1)

About $95 for each mount and $40 for the transmission mount. Labor should be no more than $300. The hardest one to change is the drivers side on the US model so I don't know if that would be reversed on your celsior. I had a friend help me do this last summer with the car on jack stands and laying on our backs. Any competent mechanic with a lift can knock it out in under 3 hours. The most time consuming part is getting the nuts off since there is not a lot of room to work with and you can only get maybe a half turn at a time. The first pic are my old mounts and the second pic is the tight space where the drivers side mount goes.

Greg5OH

leaking seals would have no impact on this, that is not a pressurized zone like an oil gallery or OCV (wrong camshaft phasing would give a rough start).

Try changing your tranny mount, 35$ new OEM one. I was simply blown away how big a difference putting a new one in made.
Start up is butter smooth again and no rumble around 2k rpm.

sha4000

iTrader: (1)

I changed all mounts this past summer but I am wondering if maybe I need to go back and retorque the nuts. I feel a slight rumble in the body while idling also.

Greg5OH

if you jammed em on nice adn tight it should be fine. Rumbling in the body at idle...whole slew of things could be causing that.. dirty OCV, dirty MAF, dirty TB, older plugs.

I had a huge random bucking from my car while just crusing, felt liek u just hit a speedbump on the highway. cleaned TB, changed plugs (only had like 50k miles on them) and cleaned MAF...it went away..couldn't believe it!. Idled good before that.

Clean the TB, new PCV, new plugs and clean MAF (i used CRC maf cleaner). My plugs were like 38$ from rockauto. I dont believe in that double platinum iridium yada yada, thats for plug longevity. Id rather change my plugs 2-3 times as often and have peace of mind of having fresh plugs. I got some ngk one that was a favourite.

Sorry if you know or have done all this, just yammering.

sha4000

iTrader: (1)

That why I figured it was from the oil leak in the front. Maybe the oil is low on start up. I changed all the plugs last year back to iridium. I have the TB kit already and have the cam and crank seals, PCV, Valve Cover gaskets and a slew of other parts in my basket on SouthAtl. Just waiting to pull the trigger and take care of that in the next couple of weeks. I'm trying to find a good tutorial on changing the cam seals since that looks like the most challenging part of the job. I have the manual but It does not really make it clear on how to do it and I can't find a good how-to other than hold the exhaust cam with grips.