Thump Sound upon tack off

[19steelers74]

I have a 99' Boxster. It has about 105,000. And I need help determining the sound its making upon take off.

So when I'm at a stop, and I decide to take off hard, it makes a thumping sound as if its the motor mount or something. But if I take off slowly, it doesn't make the sound.

Any suggestions?

[jerry and sons]

I would guess the motor mount. If that does not solve it,head to the trans mounts.

[steved0x]

Yeah that's my best guess too, motor mount. When it goes bad it can bang around pretty good back there.

[Dubaday]

I might have developed this problem as well. I wonder if it might be the transmission mount instead. How can you tell the difference?

[steved0x]

I replaced my transmission mounts recently and while the feel of the car is greatly improved, there was no banging on the old ones, I think they are made differently than the engine mount.

[geetee]

tranny mount can contribute but the thumping is the motor mount. updated 987 mount fits fine. I was going to add motor mount inserts to stiff up stuff but motor mount was totally separated so just got a new 987 mount. This is on a lower mileage car. I've had/have many 986 996 cars and every single one has/had a failed mount

[thstone]

Most likely motor mount.

The trans mounts are filled with fluid and even if the fluid leaks out, there is still usually some fluid left inside which dampens the motions and keeps them from banging about.

[19steelers74]

Thank you all very much. Thats what I thought it was also, just needed to make sure.

[19steelers74]

So how many Motor Mounts does this car have? One or Two?

[JFP in PA]

One for the engine, two for the transmission.

[Anker]

One!!!!

Didn't you just ask the same question in another thread?