sailor95

Hi all, today I bought my first ls400, 1999 with 201k for 4000. Previous owner had meticulously kept up with records which I have from 115k in 2011 to just two days ago on the 23rd when installed new battery, clean carfax with last reported at 198k. Runs great, got 25.4mpg from hilton head to my home in statesboro. One question I do have is a shutter/vibration as the engine revs to life after start. The engine and trans mounts have been done also exhaust and valve cover gaskets, serpentine, timing, water pump, even had new rack and pinion and TRANSMISSION! It runs great but this vibration at start up and rev is something I want solved

RA40

iTrader: (6)

Congrats on the LS!

We've had these threads pop up and with minimal conclusions on the culprit. The engine and transmission mounts are the first thoughts. One past thread it had been suggested to check the battery voltage and if not up to spec a new battery. In that member's situation he reported this solved the cold idle vibration.

sailor95

So does this mean not to worry? I put a bottle of Lucas upper injector in it this morning and itll be driven to Augusta tonight by my girlfriend. Had a mechanic buddy check it out and no leaks and passed his inspection. I'm wondering if it's because of the prev owner not driving for a while and it staying in garage so buildup in engine

billydpowe

iTrader: (1)

when you are just chatting, without facts and throwing out ideas, go ahead and let her drive it and see if you have any improvement on her return..
keep us posted for helping others...

400fanboy

My engine shakes the car when I rev it while the car is in park\neutral. No vibration at idle or in drive.

I have no clue what it is. Motor mounts are fine, many mechanics have looked at it and given it clean bills of health. Similar to what yours is doing?

sailor95

Yes very similar, I have not gotten any bad report from significant other on driving today in Augusta as a nanny so im guessing this is just inherent to the vehicle. My father owned a 98 years and years ago and he sat in and cranked and said that was very normal and his did the same thing

billydpowe

iTrader: (1)

well it's me again with some facts for you.... I have driven my 99 LS for over 10 years now and I do not have any vibrations, or shaking in the car, or steering,
at any speed,(up to 120mph, my limit) setting still or revving it up.. SO YOU HAVE A ? problem? situation? something isn't right? good luck to you.

billydpowe

iTrader: (1)

remove the belt and run the engine, see if you have vib...

400fanboy

He\we are talking about vibration in neutral or park. Driving it is completely fine.

It idles perfectly smoothly so I don't care. Just a little quirk.

jaaa

It shouldn't vibrate in neutral or park. Pull the drive belt and see if it goes away. An excellent idea from Billy. Take a few minutes and won't cost you a thing.

Losiracer2

My 97' with new Lexus mounts was a huge night and day difference compared with my old ones. You shouldn't feel ANY vibration, either through the wheel or through your seat. A car with new mounts will feel completely isolated and you'll have to look at the tach to make sure that your engine is on during startup. I don't even feel mine fire up and I've got 299k on it. It makes the driving experience so much nicer too, shifts are better and more controlled, you won't feel the engine's bulk moving around and NVH is much improved. The front end will feel "tighter" in a way.

Start with the transmission mount first, then move onto the engine mounts. But if they're all original, then most likely they're bad, the youngest LS is now 19 yrs old. When rubber is that old, it's for sure not doing the job it was intended to do and is dry rotted somewhat.

sailor95

Alrighty I will definitely try removing the belt this weekend and seeing, just wierd because it was meticulously kept. Motor and transmission mounts have already been done and in the service folder with receipts to prove.

400fanboy

Ok. I need to replace it anyway so I'll do that once I replace it.

Engine is okay to run without the accessories for 15 seconds?

jaaa

sure, no problem.