Technical Bad noises and Terrable Smells

[faster4_tec]

MK1 60s,
ever since i got it the cars been making strange kind of slipping/ sip sip sipsip siiippp noises as you accelerate (no matter how hard) and can be temporellory cured by declutching it revving a little then continuing on. It only does it occasionly but its really annoying, makes the car sound like its powered by hairdryers.
Since yesterday the engine has been making some terrable burning plastic/ rubber/ melted plastic kind of smells, it did it yesterday morning then again last night so i decided not to use it today incase it is terminal.

Any one shed some light on what it could be??
I reckong it could be the cam belt cover rubbing on the cam belt.
or my mate reckons it could be the brake servo is this correct??

 

[dave]

i think you may be right and mate is wrong

 

[faster4_tec]

cheers dave.
I've sorted it now, the smell was the brake servo getting stink hot as one of the breather pipes from the servo the manifold (?) was blocked with manky congealed oil. smells OK now
and the cam belt cover was loose and movemaround, had a look in and can't see any damage but secured it any way.
its still making the noise though

 

[rpaterson]

The noise could be caused by an air leak somewhere in your inlet ducting. When you're accelerating, the engine is pulling air in through the split or hole.