O.k, not really good at explaining things but ill have a go.

About a month ago i started hearing a thumping/knocking sound (abit of a duh duh duh duh sound) coming from the engine bay behind the middle of the dash or maybe under the pedals. the thumping isnt very loud but is annoying, and only starts while accelerating. It doesnt make any noise while idling or foot off the accelerator (even while moving). My mechanic has heard the noise and said the transmission needed servicing so i got the whole car serviced while i was at it and while the car drives beautifully the knock still continues...It sounds very similar to a bubble in the tyre but i have just bought new tyres and have had them checked and tightened once the sound started. i have also just had new lowered springs put in. CV joints were also mentioned by my mechanic but i think he has moved past this theory (but if this sounds like a CV problem ill bring it up again). The timing belt has been replaced also.

Its a 1997 TF Auto. 160000km on the clock.

by the way i did use the search function and although alot of "tapping" threads came up they didnt really sound like my problem. Any help would be appreciated :)

Edit: i have been driving it pretty much everyday with no change in sound or drivability.

You could check the cvs by putting the car on full lock and doing a u turn, first in 1 direction, then the other.
Worn cvs will click or make a noise as you turn.

You may also have a tyre touching the suspension under accelleration due to movement from engine torque. If so you should be able to see rub marks on the inside of the tyres.

it usually starts making the sound while im holding my speed between 40-80, but as soon as i take my foot off the accelerator it stops even between those speeds. it doesnt seem like a rubbing problem as it stops as soon as i take my foot off the accelerator at any speed. I just had a quick read about CV problems and i dont think thats whats wrong. any other ideas?

"shudder or vibration when accelerating" does seem to fit the bill so ill get someone to check it out. thanks and hopefully this will solve my problem.

should i stop driving it or is it not that serious a problem?

check all the engine mounts

the front on on a v6 usually breaks

you lowered the springs
a lot of posts about suspension/shock/
and bump stop problems after lowering
and body/tyre clearence

also rear camber kits

ok to keep driving if
all the fluid levels are right
the car steers straight
the brakes work