CanadyLex

Hello LS Fam: I am having a vibrating issue when i first start the car in idle. Havent noticed it in reverse but only when in first gear it vibrates not constant but like a moan........... moan.......like i have a woofer in the front fender..lol but clueless. i just had the tranny rebuilt.. could it be something there or should i take it to the dealership and get a diagnostic? when i first bought it was super quiet... i looked in the trunk to find a oil treatment bottle.... wondering if this is a clue that there is some known build up.....just really need some help before i get hit with a diag. fee. for real

it is a 1995 Ls400 176k...................

NugenLs400

i got a 95 ls400 with 225k and im having a similar problem but when i read other ppls post a lot of them said to turn on your ac while its idling low and shaking, if it stabilizes then it can be your engine mounts going bad. I'm not sure whether or not this is true but when i turned on the ac in my car the idle returned to normal.

NugenLs400

i also saw someone else say to open your hood and tell someone to rev your engine and if your engine shakes a lot its a sign of your mounts going bad, just something i heard >< hope it helps

deanshark

To test the motor mounts by looking at the engine, you need to put it in gear (drive and reverse) and give it a little gas. If the engine jumps then they're bad.

etex

Be sure one foot is firmly on the brake.

CanadyLex

Thx. I will check it today at 13:00 will let you know the outcome...

ghenley

Yes, when this happened to me, it was the motor mounts.

NugenLs400

i hear theyre expensive to fix also ><

CanadyLex

Well i got my estimate back and it turned out to be the motor mounts for the intermitent vibrations. Was quoted $588.00(Parts and Labor) at Eskridge Lexus (OKC) to replace both. Now i wonder how difficult it is to replace your self??????

MicahBerry

CandyLex,

The following is a tutorial for the motor mount replacements:

https://www.clublexus.com/forums/ls4...placement.html

You could also call around to a local independent shop to see if they would replace them for you and at what cost. Lexus dealers are expensive! If you're concerned about parts quality, then ask the shop whether they might install the OEM parts you bring them.

As an FYI, you can install the transmission mount very quickly. It's easier than changing your oil (and faster). I got my parts through Sewell with my Club Lexus discount. The discount has been excellent, making Toyota parts about as inexpensive (and in some cases cheaper) than aftermarket parts. I've been pleased with their service and shipping times. I have not installed the two motor mounts myself (just the tranny mount). I've got a couple other projects to complete before doing the motor mounts.

Truthfully, when the time comes I may order the OEM mounts, and then take them to an independent shop to install. I believe it'll cost me about $200 for the install of the two motor mounts for labor (just my guessimate).

Hope that helps.

Micah

CanadyLex

MicahBerry, thanks so much I will look into getting this project started ASAP. My dealership here does wonderful work but a bit pricey. However My service writer stated that if i dont change them and i accelerate to high my engine may damage my motor fan... Is that true.... kinda makes me nervous to give it some real pedal to the metal.. I will just drive under 45 until i change them.... i primarily drive the vehicle back and forth to work so that is attainable for now( 10 miles one way) thx to everyones help and will update asap on my progress.

deanshark

If you know for a fact that the motor mounts are bad then change them ASAP b/c he's right, sort of, if you nail the gas from a stop the mount could snap and the engine would jump which will cause more damage then just the fan. As long as you're easy on the throttle you should be good. I've seen alot here that were cracked in half and noone ever complained about jumping, just vibrations.

MicahBerry

CandyLex,

Unfortunately, I'm not a real mechanic, just someone with gear-head leanings that has learned some stuff the hard way. You can do a simple test to check your mounts by parking the car, raise the hood, and then move the gear shifter to drive, check to see if the motor moves much as the transmission engages the gears. If there's not much movement, then with the gear selector in drive, GENTLY give it a little gas. The motor should obviously move if the mounts are broken.

If your mounts are broken, I wouldn't stab the gas... The engine is heavy but torquey (if that's a word), but you could break something when you apply enough gas.

I'm looking to replace mine to restore super-smoothness, not because they're broken. You should note drastically improved smoothness once the new mounts are installed.

Also, be sure to scour this site for anything "Motor mount" or "engine mount" related. If you choose to do this job yourself, there are a couple items you'll want to remove to keep from breaking them when you lift the engine. I don't recall what they are right now, but they seemed reasonable. The tutorial I posted doesn't reference what to take off.

Lastly, if you choose to have someone install the mounts for you, ask for the old mounts back. You might find they're in pieces! When I have mine done, I'm going to find what parts need to be removed and make a list so that the independent shop is aware and can avoid a potential misstep.

Regards,
Micah

JBrady

My 99 did that until I replaced the trans mount. Smooth now.
I also have to believe if you just had the trans rebuilt it would have gotten a new mount as they come appart when bad. Check your receipts and or call the shop who did the work.

That said I believe my motor mounts also are bad and have the parts but have been holding off due to planned header install (hate to do things twice).

I think the mounts commonly break somewhere over 100k miles. At 176k yours are almost certainly in need. DIY is not too hard if you have basic skills, tools and a backup vehicle in case you need something unplanned (always seems to happen)