Tabaka

iTrader: (8)

Last night I was driving home from work and accelerated harsher than normal to get to my highway exit. I probably brought the RPM's up to 5,000. When I let off the gas and got to my exit the car was vibrating and rattling. Here are my symptoms:

-The entire car vibrates in lower gears (1st, 2nd, and 3rd) between 1,000-2,500 RPMS

-I can hear a constant rattle noise near the shifter around 2,500 RPMs in 1st, 2nd, and 3rd. However, if I grab the shifter and and hold it still, the rattling goes away. The second I let off, it rattles again like a bad bushing.

-On the highway in 5th gear, it's smooth at 2,000 RPMS around 65mph.

-If I push in the clutch, all vibrations and rattle noises go away in any gear, at any speed.

Did I break a transmission mount or possibly unbalance the driveshaft? I lifted up the hood and gave it some gas from the TB to see if I could find any major engine tweaking and shaking but didn't see anything out of the ordinary.

So, what did I break this time

Vrank

iTrader: (4)

clutching in at speed the driveshaft will still be turning, so I think thats safe to rule out. Which w58? early or late model (tripod)?

Ali SC3

iTrader: (10)

you are 95 right, I had the same problem use a heavier weight shift **** temporarily and it will go away.
you probably tore through what was left of the shifter cage tripod bushings, I bought some aluminum ones and never installed them, so mine still vibrates some like you describe with the stock shifter, but with the greddy shifter which ways like double no vibrations at all, also if you hold the stock shifter the vibrations go away so thats what tipped me off I had the same thing.
also check the bolt under the shifter there is one at the bottom of it if it works loose it will vibrate like that also.

the answer is to replace the bushings, but after I noticed it didn't vibrate at all with my other shifter, I was lazy and called it a day.. lol.

almost gauranteed to happen if you put a short shifter on a triped transmission with old bushings. they will wear through the stock bushes in a few weeks in some cases.

Tabaka

iTrader: (8)

I think it's more than just the shifter bushings now. I went to drop off an item to a client a short while ago which game me a little more opportunity to try a few things.

-if the car is parked, in neutral, and I push on the gas, the entire car including steering wheel shakes and vibrates.

-if the car is parked, in neutral, and I have my foot pushed in on the clutch and give it some gas, the entire car including the steering wheel shakes and rattles.

-at idle, the car is super smooth.

All of the symptoms still apply in my first post. I'm leaning towards an unbalanced engine, possibly jumped timing, o2 sensor getting a bad reading, or maybe even a bent valve. I assume a bent valve or bad o2 would trigger an OBD1 check engine light correct?

Ali SC3

iTrader: (10)

you are still n/a right, its pretty impossible to bend a valve, jumped timing would be bad all over, and an o2 wouldn't shake like that.
you probably blew a mount then, likely a motor mount or the trans mount.
It is hard to tell by looking at the motor mounts, but when you jack up the motor they usually disintegrate if they are bad.

Tabaka

iTrader: (8)

Well I bent a valve in my S2000 once and it was NA. Low oil can cause crazy things to happen. I'll let Oumar diagnose the problem in the next few weeks. It's driving, just shaking and vibrating like crazy.

99SC42

iTrader: (44)

s2000 is like the IS300, GS300 98+ , Sc300 98+ Interference engine , jump iming and engine is done.

Mounts, trans or engine, Driveshaft.. i am willing to bet it's the carrier bearing on the driveshaft , you ripped the bushing out.

I've broken 3 of them on my SC making power, they are old 19years on your car

mecheng10

bent valve is highly improbable.
I had the same symptoms on a 93 sc300, went to take the shifter out, and there was no shifter bushing left.
when I replaced the bushing, the vibrations went away.

check your bushings!

gtsfire

iTrader: (4)

Sounds to me like a mount. If the engine and tranny mounts have never been changed then I'd invest in them. You'd be amazed how much those affect the ride and driving of these cars. Good luck! I have no experience with 5 speed SC's but replacing those bushings Ali spoke of sounds like good advice also.

Tabaka

iTrader: (8)

I'm leaning towards the tranny mount. It doesn't make sense that I revved the crap out of the car for a split moment and the shifter bushing tore instantly, causing my car to have VIOLENT vibrations afterwords. The tranny mount probably broke and I'm feeling the aftermath. Car has 168k on it now and it's probably time to replace the engine and tranny mounts considering I'm going NA-T in the next few weeks. Same thing happened with my crank pulley, decided to rev it hard one day and that sucker flew right off lol. Maybe I should just drive this car like an old lady and stop breaking things