Nasty noise coming from car

[Robin Cooper]

Hi there i need some help,
i was cuming back from collage today and it started to make a weird noise, when it was getting to high revs there was a sounds like a dump valve like a load of air is sudenly escaping, then it was getting worse so in second gear at 20-30 it would sound nasty and if you put foot down you can just hear a noise as if air or gas is escaping

any ideas or help will be much appriciated

 

[Robin Cooper]

i just been owt init again now and it is more like a rasp or like somthing is nokking in a pice of metal, it sounds like it cumin from bottom of car under front seat or around manifold area, and it is related to the revs because it only does it at 20-30 in 2 and really bad in 1st at 3 and 2 nd at 50

 

[Dusk]

Heat shield or worse case manifold.

 

[kristian]

manifold gaskets provide a kissing... wirring noise when split...

 

[Robin Cooper]

kk thnx i now it not the heat shield because i tht used to vibrate n tht is as dif noise but i will c bwt thw manifold

cheers

 

[Robin Cooper]

i think it might be my manifold, but just wondering were abouts is the is it near the front or near the middle or back, and could it be my middle box?

 

[runaway-robot]

Manifold starts at the engine block.... goes down past the sump and continues to the Cat....

if its the manifold gasket... thats agaisnt the engine... there are 8 bolts holding it on, which have to be taken off in a certain way (check the haynes)

 

[Robin Cooper]

sorri that was ment to say were is the cat? yeh i no were the mainifold is bt not sure bwt cat, is it wer the pipe widens abit?

 

[runaway-robot]

the front cat.... as soon as the manifold comes off the engine, the pipe widens ALOT.... secured with 2 screws with springs on...

OR

back cat, if u follow the down pipe under the car... it comes to a oblong shaped kinda box (best shape i could think of haha) then continues on to the back box... its about half way under the car.. u cant miss it.