for those of you have read my various posts about the knocking noise under acceleration in my mk1 172 then youll all be releaved to hear, i no longer have the noise and will now shut the f**k up about it
thanks simon172 for your input, my car blokey rang smc woking and spoke to their "172 expert" who has had "loads" of 172s in with the same problem....
and the answer is (for anyone else who has this problem);
Yes, it is the exhaust banging on something due to engine movement but it is not down to any adjustment of the engine mounts as such...
its due to the mount situated under the battery i.e the right hand mount either being loose or broken (in most cases).
If it makes the knocking noise all the time when changing gear, its probably broken, if it just does it when pulling away, its loose....
That particular mount attaches to a bracket which then attaches to the gearbox....
its an arse to get to as getting a spanner to the bottom end of the offending bolt is difficult but we managed it and it was very loose...
tightened it up..
put the battery and airbox back in again.. and no knocking noise anymore....
and the best bit being, i was charged £10 for over an hours work
so thats that ordeal over