Front end vibration at low speeds&rpm?

Hi everyone! My name is Cristian, I have an auto '91 3000GT SL.

The front end of my car bounces/vibrates while the engine is at low RPM. Usually only when its under load, like accelerating, but it also occasionally does it in park at idle. Its worst when in reverse while easing off the brake, when im backing into the driveway.

My mechanic says he has inspected everything in the engine bay that he can without taking apart the engine/trans. Says if I want to continue trying to find the cause he will have to start charging labor when he opens up the engine. Apparently he has something similar months back that “turned out to be the cams” so thats where he wants to start.

I think it could be the torque converter or harmonic balancer but then again, I have no clue what Im talking about. He doesnt seem super confident, and I dont have cash to be placing $400 bets on where the problem is. Any suggestions/ideas?


Wait a little until until you can get some suggestion from people around here, because you can end up with crazy repair bill if you go searching for things that turn out to be not related to the issue.

Stay far away from that mechanic. Someone claiming to be a mechanic saying they want to start with the cams for vibration under load is no mechanic I would trust to work on even a tricycle.


I’m with srealthee. Don’t go back to him. Do you have fwd or awd?
If you put the car in neutral with the parking brake on, can you produce the symptoms?

It is FWD, I havent experienced the problem when the car is in neutral.

Seems to start acting up as soon as I put it into reverse from park, or when I accelerate from a stop where I was just sitting there with my foot on the brake in drive.

Just got off the phone with the mechanic, gonna pick it up from him later today, not letting him comtinue to work on it.

He said he can get it to vibrate when its in park or neutral by revving it up a little. I will verify when I pick it up but it looks like it can actually be produced in park and neutral.

I would start with a basic tune up. Do plugs and wires if you don’t know the age. They could cause the exact issue you’re having

Got the plugs and wires done already, that was the first thing they did.
I just picked it up and its way worse than when i dropped it off. The vibration is crazy, whole engine shakes around when I rev it. Also, now it feels totally gutless, like super low power.
Sounds very choppy and again, super bumpy at low RPMs.
Hopefully my engine isnt trashed :frowning:

Have you checked that the engine has broken 1 or more of its engine mounts???

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I will spend some time on it this weekend and chech that for sure. Pictures to come.
That would explain the vibration but im scare to speculate on where the loss of power is originating from. Maybe torque converter is going back? Or maybe multiple cam lobes are missing?
I will keep this thread updated.

If the engine is running bad all the time now. If you have a DOHC engine, I would think that maybe one of the coils or the TCU is bad. One of my coils went bad a few years ago and the engine ran terrible all the time. It was shaking because only four of the spark plugs were firing. Each coil on the DOHC engine fires two spark plugs.