en11871

Hello Guys,

I'm wondering what are the symptoms of worn/bad transmission and engine mounts? I'm hearing/feeling some noise, but pretty faint. The noise I'm hearing (seems to be in lower rpm) sounds like when exhaust is bad. I really can't describe the noise...like dud, dud, dud, dud...but very soft. I hearing/feeling the noise from the front though. So I'm just wondering if my mounts need to be changed...one more thing I have noticed recently is that when I turn over the engine it shakes a little more than usual. Please help. Thanks.

1996 LS400

Neofate

iTrader: (1)

Often, bad motor mounts allow the engine to rock and move around, causing noise and interference problems with the throttle, transmission and clutch linkages. For example, a thumping noise when the transmission is put into gear or when the vehicle is accelerating is a classic symptom of a bad mount.

Cracked or broken motor mounts can be an annoying source of vibration and noise, typically a clunk or shudder when accelerating hard.

Tranny mounts have similar symptoms.. It is generally a good idea to get these items replaced after 100k miles or so (or 8-10yrs) at the most.

Your engine won't fall out as a result of bad mounts, but the vibration can cause other problems as I alluded to.

I replaced my motor and trans mounts a few weeks ago, and the car feels much tighter, and is 'quieter' overall at idle and at speed.

If your mounts are even 50-60% worn you will find a noticeable difference in replacing them.

Yes, an engine shaking more than usual on startup is a classic sign of worn motor mounts.



The sound you hear might be an EGR leak. Hard to tell by a description alone.. I would change those mounts and see where you stand from there, it sounds like they need it for sure. Then address the other issue afterwords.. or tell the mechanic of the sounds, see what he thinks and go forth from there.

I have a slight EGR leak on my 94 LS 400 -- and on a cold start you can hear it (exhaust leak) till the pipe warms up and seals itself off. I would fix this, but it is an extensive labor intensive process, that is about 8 hours worth of work for a competent mechanic. For myself, it would probably take a few days, plus I hate working without a lift.

I'm sure others will jump in and give you their thoughts.

Btw, motor/trans mounts aren't expensive.. for a few hundred you should be able to get the parts and have them installed.

en11871

Neo,

Thanks! I'll get the mounts done. I was told the engine mounts or the tranny mounts come in 2 pieces right? PLMK. Thanks again.

tbilisi79

Bad tranny mount will give constant vibrations on the road. Annoying as hell.

Neofate

iTrader: (1)

Sure thing -- I won't guarantee it will solve your noise.. but it will make a noticeable difference in ride and the stability of your engine.

The engine mounts are two pieces -- yes, one for each side. If I recall correctly the transmission mount was one piece.

Let us know if it helps.

en11871

Neo,

I mean that each engine mount has like a metal frame and then the rubber piece right?

Neofate

iTrader: (1)

Maybe this will give you a better idea:

http://catalog.drivewire.com/drivewi...t=Engine+Mount

en11871

Neo,

..."FrontReq. 2. Dealer sells this together w/ part # 12381-50080 which is the rubber engine mount stabilizer. We carry 12381-50080 separately"...that's what I was referring to.

damon

Not unusal to have the rubber come out in 2 seperate pieces on older LS400 mounts.

Should be easy to spot up on a rack. Old broken mounts are a likely cause of EGR pipe cracking.

BTW: People are making way to big a deal out of how hard it is to change/replace.

LiCelsior

iTrader: (32)

so many NY LS owners now....chime in to the NELOC forum guys(http://sr1.clublexus.com/forums/forumdisplay.php?f=175). need to change my tranny/motor mounts soon...tranny is easy but motor might be more difficult. i also have a exhaust leak..sounds/looks like its from the exhaust manifold?? guess a exhaust leak is common in the 1LS lol.

en11871

Damon,

Thanks for your info. So you're the second member that suggested it can be the EGR. So if the EGR pipe is broken because of the engine mounts, is it a PITA? I'm wondering about the price of part and labor for that pipe. Let me know.

Neofate

iTrader: (1)

Indeed mounts are likely cause of EGR crack.. it isn't that it is 'hard' to replace the pipe, but it is a time consuming process.

I've never done it, so I can't speak from first hand experience, but the rated hours are 8-10.. So even an Indie mech is going to charge 400-500$ in labor alone.

If you want to come change my EGR pipe out for 100$, be my guest

en11871

IMHO, don't think you would even want me to change your light bulbs...LOL

so what is that pipe called exactly...egr pipe? thanks

JesLet

iTrader: (19)

My broken tranny mount from my SC400 makes whirling sound when coming to a stop.

Replaced it with a brand new one for $70 and the noise is gone. Installation is easy.

en11871

Neo,

I'm looking at a parts catalog. Looks like there are EGR pipes 1&2. Pipe is a shorter one than the pipe 2. Which one of those pipes can be broke by the mounts? PLMK.