Hiss and Rattle

[gav1pam]

I own a 04 Dynamique 1.6 VVT
I've had it for just over a month now and a ratteling noise has started from the front offside when moving.
Its not to do with the wheel/breaks or anything else in that reigon.
I've removed all the plastic covers and tried it with out but i still get the rattle.
Also i've been told this is normal but just want to check as i havent heard it before, when i touch the
accelerator there is a quick hiss/sucking noise coming from the engine bay.
Any help on theses questions would put my mind at rest

[dougieCC]

Is it a knock, or sort of a clunk when you use the steering,if its a knock over uneven surfaces, could be the anti roll bar link, although have not heard of them being a problem.

Alan

[gav1pam]

No, its more of a metalic rattle coming from the centre underneath the engine as far as i can gather.
Its not there all the time, mostly at low speeds.
I dont think its the exhaust either becase it makes no difference at higher revs.
Also its not there when the car is stationary.
Any ideas on the hiss?
Thanks
Gav

[chris2008]

do you feel a vibaration when sitting in drivers seat when car is idle? if so i get the same rattle, its like a tiny/metal sound and cant be hurd when driving mine been back to arnold clark about 5 times about this they told me there could be a brick in the exhaust , i thought wha a load of bull sh1t , still does the rattle now

[gav1pam]

no, i get no vibration.
someone mentioned to me it could be the cat on its way out.
ill check it and let you know

Still anyone on the hiss??

[markren2004]

hiss might be a air leak in the air intake, check all the sections of the air intake are on tight and there are no signs of any holes and also that the throttle body is on tight.
other possibility is a leak/crack in the exhaust manifold, but i wouldn't expect that on a 5 year old car ?

[Paddy]

I aint an expert, but a hiss and a rattle sound form under the hood would suggest a compression test was required. It would eliminate a gasket on its way out.

P

[gav1pam]

Im no mechanic...do you mean a head gasket?

[megane09]

is the hiss loud? coz if its not loud id say its jsut teh air intake sucking in air, which is what its supposed to do, when u press the accelerator the hiss could possibly be just the air intake, as for the rattle does it only do it when ur jsut movin forward or all othe time?

[gav1pam]

Its quite loud, you can hear it with the bonnet down.
I was told it was the intake, but i just wanted to check.
as for the rattle...its stopped
no it wasnt all the time, just a low speed, not when stationary, and it didnt rattle more when i revved.
I know its gone, but i'd still love to work out what it was.
Cheers

[dougal]

The rattle could also be cat, converter breaking down internaly will show up on exhaust gas analyser. Happend me!