year: 1994
make: Mitsubishi
model: 3000GT VR4
mileage: 145,000
trans type: 6 speed
recent maintenance: plugs, radiator hoses, air filter
recent modifications: stock
other modifications: stock

Since having recently replaced badly eroded plugs I've reclaimed a significant amount of torque. I now notice, during hard acceleration from a stop, that there is rapid bumping noise (about 5 or 6 thuds) coming from the rear of the car. Switchiung the active suspension from tour to sport had no effect.

Any suggestions as to what could be causing this noise, and if there is a way to correct it?

Thanks, Robert

sounds like propshaft rubber bearing mounts

I had the clutch and the propeller shaft carrier bearings replaced in late 2007. I just checked under the car and the rubber bearing mounts look new, and appear to be securely fastened. There is a fair amount of movement when I tug on the prop shaft, but it looks to be the normal play attributable to the rubber in the bearings.

Is there something I'm missing, or perhaps is there another possible cause?

Thanks, Robert

it maybe the exhaust!

Tony

Explain rapid bumping noise.

do you feel it does the the car sputter?

It sounds/feels like something mechanical banging in the rear of the car, by the rear wheels.

The car/engine does not hesitate/sputter, there is plenty of power there and the tac is steady/smooth.

I thought it might be the rear wheels hopping, but I'm now thinking it has less to do with the suspension, and more to do with the drive train (rear differential?), or motor mounts.

Thanks, Robert