Hi,
I just purchased a 1996 Lexus SC400 with 204000 miles. The problem is that there is a vibration in the car both at park and in drive that varies with RPM. Idles very smooth, no check engine light, very good power (but not tire squeeling power). When I rev it with the gas pedal, there is a distinct shudder inside the car both in park and in drive. It comes and goes at various RPM. If I rev it from the engine compartment, I can feel no trace of it in the motor, so I assume it isn't the motor doing it. Here's a list of things I have done to the car:

Changed Spark plug wires, distributor caps and rotors. . .b/c there was a miss in cyl. 5 and 7
Changed Brake pads (front)
Have not changed spark plugs yet, but plan to do so with next pay check (wires, caps, rotors, and brakes set me back several hundred dollars even though I did it all myself)

What could be causing this? My first instinct tells me it could be the torque converter, but I'm not sure. Also, the car seems to cruse at somewhat high RPM. at 55 its at 2000 rpm and at 75 its at 2700 to 2750 rpm. This also leads me to believe that it might be the torque converter as my grand prix v6 does 75 around 2400 to 2500 rpm. Not familiar with this type of car, though. It may just be normal; I don't know. Any help on this would be appreciated! Thanks!

PS: sorry so long winded, I just wanted to be thorough. Thanks!

motor and trans mounts!
i havent tried this but you can try slide a small jack under the car and lift the motor and trans up an inch and hop in the car and see if it vibrates. assuming that the car vibrated even with the car not moving this may cure the vibration making it 100% engine and trans mount faulty.

I will see if the toyota dealer can test the mounts on Tuesday as I don't want to damage anything. I am going to get them to change water pump and all belts (tune up) as I don't know when the last time it had a tune up. About the rpm though, is 2700 rpm normal while going 75 mph in these cars? I am not familiar with them and wanted to know. That would tell me if I'm having any transmission trouble (although it shifts pretty well for a car with 205000 miles). If I get down on it, it shifts pretty hard, but smooth if I ease down on accelerator. I can barely tell that the torque converter is locking. Thanks for the reply!

yea the rpm is normal. im pretty sure its the mounts though.

Thanks for the reply. I believe you are right b/c I can feel a clunk when I put it into gear. I noticed it after you mentioned the mounts.

Mine - similar vibration - The culprit was the transmission mount however I went on and replaced the motor mounts as well while they were under there.

My 1996 SC with 86,000 miles had the exact symptoms. Change both the engine and transmission mounts and the car will be glass smooth. Well worth the $$.

T.I.

Wow. This is gotta be the most common question asked on this Forum. Jzz30 I'm going to Pin this Forum.

can someone post in this thread the exact part numbers that are needed if one was to replace their tranny mounts and engine mounts? i would be most appreciative.

TO CHECK THE MOUNTS YOU NEED A FRIEND AROUND!

START THE CAR OPEN THE HOOD HAVE YOUR BUDDY PRESS THE BRAKES AND PUT IT IN REVERSE THE REV IT WITHOUT LETTING THE BRAKES GO KINDA STALL THE CAR AND SEE IF IT MAKES THE MOTOR JUMP THEN DO THE SAME IN DRIVE IF YOUR MOUNTS ARE GOING BAD OR ARE GONE YOULL SEE THE MOTOR WANNA JUMP OUT OF PLACE! HAY IM NEW HERE BUT NOT NEW TO CARS TRY IT OUT!!!!

305Pimpc:
we really don't use capital letters on the forum. So for future posts please be mindful of others and take the Caps Lock off.

I've also seen a similar vibration problem in my SC400. It's a '93, so chances are these engine/trans mounts could use some replacin' by now...

Anyone know about how much to expect for this type of service?

(A lot of times if you walk into a garage for an estimate for a "non-essential" repair like this, they see it as a green light to warm up the shaft for you...)


Cheers!

Mine is a 95 model and I notice a slight vibration, a dull roar, when reaching a speed of 55 or 60. That is where it begins. It almost sounds as if it is below the shifter or console in between the seats. If not for this noise, the car would be very quiet. I plan on taking mine in for inspection and will let you know what it turns out to be. Thanks to all before me, that posted possible causes, so us new members have somewhere to start.

Just took the mount off my 1992 yesterday due to hard parked gear selects and little bumb when switching to overdrive, and some vibration in overdrive at low speeds. It wasn't broken put stock has A LOT of play, i can move it just by twisting, but was still all together. Got the idea from Club Lexus forums to reinforce with high PSI epoxy, two part mix together nasty stuff. I will post pics of the whole procedure if desired. It was super easy even for a garage dummy like me. Didn't fix my prob, must be motor mounts, eh. Did notice a nice difference in shifting and direct throttle from epoxy.

Click to view attachment
I'll take it back off to do the motor mounts and see if it holds up and possibly put another layer of epoxy in the gaps.

About service times, it took me on ramps lying on my back lifting up trans pan with scissor jack from trunk and not able find my tools after i lay them down 30 minutes of actual labor. And thats with me being really unorganized and not a good mechanic period AND cleaning to dog s**t out of everything. Hope that helps.

I really don't want to pay $300 for megan mounts. Anybody know a GOOD place to get oem front motor mounts?

I tried Autopartswarehouse.com and was charged and then refunded a few days later with no notice or explanation. I then contacted Partsgeek.com and was called by a real person who assured me at least 2 were in stock. I made my order and within 15 minutes received an email explaining the part is not in stock and i would be refunded. WTF!

I don't want to pay dealership $100+ each but is that my only other choice? Any comments or local dealerships that are not scam artists would be greatly appreciated.