After all these years this is still a great and helpful thread. I will be doing my engine mounts soon. I did a deep search and found this.

 

Hi,

I could use some help if possible. I have a LS 400 2000 model. It has 96000 miles on it and it has started to vibrate at idle. Doesn't matter if its in neutral in in gear. It doesn't get any worst when I speed up. For a while now I thought the vibration was my cell phone going off lol only now has it gotten worse and the vibration is obvious. I popped the hood and the motor seems to be running a little rough.

I have never had it tuned up nor have I ever done anything with the motor mounts.

I had the oil changed in early July and the guy who does it always tells me what a great car I have. I only run 93 octane and have always used Amsoil 0-30. I drive about 5k miles a year.

Any ideas what is going on? Any help would be appreciated.

Thank y'all,

John

 

Can someone please tell me how much clearance is needed to free the motor mounts? I could only get the motor high enough to barely free the bottom bolts, but I did not have enough space to remove the mounts. Any advise or tips?

 

Easy way to check motor mounts, pop hood, have friend in driver seat. press brake (holding down on brake pedal) and give the car gas. If the motor moves you have bad mounts. If you're doing both motor mounts you might as well replace the tranny mount too. Don't forget to make use of your Clublexus discount at Sewell parts! It helps. I don't recommend aftermarket mounts like anchor they do not last as long as factory motor mounts but do have lifetime warranty depending on some stores.

 

Thanks for the advise, but i was seeking help with the removal of the motor mount. More specifically the amount of clearance needed.

 

Not towards you. it was for anyone wanting to check there mounts. Just my .02 cents since you guys bumped this old thread. Might as well ad some info to it.

 

Hey, don't know if you did them yet but here's my DIY advice. I've done a few sets and just installed another set the other day.

Remove the oil filter and unbolt the wiring and hoses on the pass side that are bolted to the block.

Once you get all the nuts off the mounts, you can put a piece of 2x12 under the motor and use a jack or a tranny jack if you have one.

You can get the motor to go just barely hight enough to get the driver side out first, then you can rock the motor a bit and get the pass side - I suppose you could do it in reverse order, that is just how I did it.

 

I attempted to replace my motor mounts on my 99 GS300. I had to stop because I could not get the mounts out. I was able to remove all the nuts, lift the engine with the 2x4, I even lifted the transmission a bit just so the engine and tranny were both level (I read this in a previous post). I could wiggle and twist the mounts, they were completely loose and ready to come out, but I needed an extra inch and half or so and I couldn't get up because the engine was already touching the firewall. I don't want to take my car in although I was quoted $295 for all three mounts without parts. I've done all my work in my garage (timing belt, shift solenoid, LBJ's, blah blah) so I'm handy and somewhat mechanically inclined. What am I doing wrong?

 

not doing anythign wrong. but you can loosen the front cross member to give you that extra clearance.

i just did one this past weekend for someone. pretty quick

 

Marshun,

Thanks for the information, but I have a question. I attempted to loosen the subframe/cross member, but it's attached to the steering rack. I didnt want to get into that and create more issues for myself. Is that the cross member that you're talking about?

 

thats the one. loosen it. it wont hurt anything

 

Finally completed this task! No more vibration! Thanks for all the help guys.

 

Greetings to all!! First post for me on CL..

Thanks to all the great posts here on CL, a ton of information contained within this forum.

Wanted to share some info about the generation 2 GS340 01' to be more precise. I have recently began to tackle the engine mounts and have discovered the best way to remove the passenger side is to take out the alternator. Should only set you back about 25 minutes with doing it this way.

With the alt out of the way, its a clear shot to the top bolt where it can be removed with a 17mm socket. The Driver side mount, coming from the other side using a ratcheting closed end wrench is the best way to tackle the top bolt.

The bottom bolts are contained within the cradle and closed off with a plastic shield. After getting the nuts off, i used a 2x4 piece and jacked up the engine on the oil pan very carefully. it takes a little bit of nerve doing this as the car wants to raise up as well. Keep checking the mounts clearance until such time they are ready to slide out.

My mounts were no longer in serviceable condition as the top portion was almost torn completely off. A tremendous amount of pressure and strain these items forgo. The difference in drivability and overall performance and feeling is hands down awesome.

Some of the pre mount symptoms i was experiencing were, on a kinda hard acceleration the car would make a terrifying thumb and jolt. You will know it when it happens... At 70mph to 80mph a lot of vibration and shaking. Starting her up was almost like you were on top a tractor cranking it up to mow the lot.

I could probably name a few others but you should get the point of what was happening. Hope this helps out anybody experiencing this issue or if this provided a building block to complete their repair.

 

FYI- my mounts were shot when replaced at 70k miles. They weren't completely broken in half or falling apart, but both were split right open. This was a one owner vehicle driven by a middle-aged woman. They have have actually split when I was driving the car hard at the track, but the bottom line is that the rubber has deteriorated over time and these need to be replaced regardless of mileage if you intend to do any aggressive driving.

 

Yep, an often overlooked repair/maint issue...on all vehicles.

My '09 Cadi with 70K miles just blew motor mount...granted its a 6.2L 410 HP engine and I tow, but point is they break.

Another common thing to overlook are the Radius Control arms which come off the front wheel knuckles, and ther upper/lower control arms...those rubber bushings break down...the radius arm one is almost 3" in diam, and my pass side is completely blown...

then there are body mounts etc...rubber breaks down :-(

Its amazing how rough the idle was in my GS with broken motor mount...far worse than the cadi (S6 vs V8 ?)