new noise since fitting manifold

poundy

there is a sound coming from under the bonnet which i just can suss out.its only since i fitted the new stainless 4-1 manifold.
to be hounest it sounds like its blowing but ive been over every inch of the exhaust, and ive even taken it back to my mates garage but we just cant find anything.
there is no sooting anywhere which would give away a leak somewhere........and its doing my head in!!

any ideas??

Huskyman

A tubular manifold can and does sound different, give it a couple of thousand miles to soot up mate. When I fitted one to my Mk2 Astra (good God that's a few years ago) it sounded very different and then calmed down once it had sooted up.

old_cruiser

I know exactly what you mean here with this noise, although not quite th same; I fitted a stainless system to my 900 Diversion motorcycle and got and still get that sound as if it's blowing, what I noticed was that the thickness of the steel is somewhat thinner than original , so hence the extra sound as if it's blowing , years ago with the use of leaded fuel , exhausts would tend to quieten down pretty quick due to sooting , but with unleaded it may well take a lot longer as I'm finding with the Bike.
Cheers Pete

MikeS

massive difference in idle sound with piper 4-1 and standard manifold

does sounds like it is blowing at idle with 4-1

only way u know it is blowing at idle is smell

poundy

Huskyman said:
A tubular manifold can and does sound different, give it a couple of thousand miles to soot up mate. When I fitted one to my Mk2 Astra (good God that's a few years ago) it sounded very different and then calmed down once it had sooted up.

it sounds like its blowing, could it just be the exhaust??

poundy

MikeS said:
massive difference in idle sound with piper 4-1 and standard manifold

does sounds like it is blowing at idle with 4-1

only way u know it is blowing at idle is smell

smell from under the bonnet you mean??

MikeS

uhuh and cabin at idle

poundy

MikeS said:
uhuh and cabin at idle

i dont have a cat so i dont realy get any smell at all

MikeS

cos the zaust manifold is directly below the heater when u are at idle the fumes rise and get sucked into the cabin

one of the first things u notice when your exhaust manifold is blowing / cracked apart from the lack of low down torque on NA cengines

SriSte

Yeah it smells of oil for some reason, and my car doesn't burn any at all. My piper welds failed almost all the way round one of the runners, was spacing me out with all the fumes too :wtf:

The blow from my piper always sounded worse if it was fully heated up then switched off for 15 mins or so then restarted.

poundy

SriSte said:
Yeah it smells of oil for some reason, and my car doesn't burn any at all. My piper welds failed almost all the way round one of the runners, was spacing me out with all the fumes too :wtf:

The blow from my piper always sounded worse if it was fully heated up then switched off for 15 mins or so then restarted.

could it have cracked so soon??

MikeS

i had same problem with piper manifold

lasted no longer than 6 months

poundy

MikeS said:
i had same problem with piper manifold

lasted no longer than 6 months

and that was on a n/a i guess, so how long will mine last with the charger!! it should have a warrentee tho shouldnt it?? cant say i will be very happy after spending all that cash out for it only to last 6 months because that would just be a total rip off as far as im concerned.

poundy

MikeS said:
i had same problem with piper manifold

lasted no longer than 6 months

gonna have to take it all off cos i cant see where it could be blowing.

is there a compound i can put around the manifold together with the gasket to make sure??