Exhaust noises

[LP640]

Hi guys, I've got a 2000 406 2.0 16V with the 4spd autobox from ZF. She's recently covered 150k kms on the clock. I've noticed lately when the transmission shift from 1st to 2nd and 2nd to 3rd at abt 3k revs, the exhaust emits a sort of 'fart' sound just when the cogs are swapped. It comes from somewhere in the front to the mid section of the car.. And when I'm giving it a bootful and when the revs climb past 4k rpm, there's sort of a air gushing out sound from somewhere in the engine bay in the bottom of the car. Could it be a leaky exhaust/manifold or something from the gearbox itself? Please help guys.. Thanks

[DiscoPol]

my money is on the flexi section at the front of the exhaust just before the cat, there are a number of options for replacement: full front section plus cat= expensive or the preferred method of a new section of flexi being welded in, either way i would get it in to the garage and have them stick it up on the ramp and then fire the engine, that way they can see just where the leak is.

good luck and keep us informed,

where are you based? you mention kms in your post somewhere so im guessing you arent in the uk

[LP640]

Thanks discopol for your input. Really appreciate your help I'm taking the old girl in to an exhaust specialist tomorrow to get her checked. I hope everything is fine with the cat, because replacing the cat would cost silly money. Is there anyway specific way to check if the cat is all good? I'm from a land far away, Malaysia to be exact, and 406's here are hard to come by. So I hopped on to this forum looking for an opinion first

Btw, if I may ask, what does this flexi section of the exhaust actually do? I'm not so familiar with exhaust systems and I have not heard of the flexi section before. I've noticed that my 406 is suffering severe loss of power since this blowing exhaust issue came about. Is this normal?

[DiscoPol]

Btw, if I may ask, what does this flexi section of the exhaust actually do?

its there because of the movement of the engine on the engine mounts could damage the rest of the exhaust or crack the downpipe/manifold.

its a piece about 20cm long with a braided steel covering on the outside, its just before the cat but there is enough rigid pipe either side to allow you to chop it out and weld a replacement in its place.

[LP640]

I called up my Peugeot dealership/specialist that I usually send my car to for routine maintenance but they don't do any exhaust repairs. So I will have to get this sorted out at an exhaust specialist. I'll be going to the specialist later and I hope they can get this blow sorted cause the power loss is pretty bad and the sound is a little annoying. I'll keep you guys posted. Thanks for the help

My 406's too is suffering the usual 406's gremlins like the incorrect fuel gauge. The needle is showing that I have a little more than 1/4 tank of fuel left but its actually almost empty. The fuel level low light comes on whenever the fuel is in its reserve when I leave the ignition on and it goes off when the fuel needle climbs and shows the incorrect reading. I don't know any other way to get this sorted and my Peugeot dealership only reckons changing the instrument binnacle which I do not want to resort to. So I have just learn to live with this.

The rear suspension is getting very loose and noisy over uneven roads. I guess this is down to worn bushes, so I will have to get this sorted as well. And some of the front suspension components are dancing around over uneven surfaces, probably bushes too.. Besides this, she's drives and pulls very well. Great car I must say. I've had her for 10 years now, and its been a great driving experience every time

[LP640]

Got my 406 checked today. The problem was down to a leaky exhaust gasket somewhere in the engine bay. Its at the upper part of the downpipe and it is a metal gasket. The exhaust specialist didn't have the part for it. So I will have to take it back to a Peugeot dealership who will probably have the gasket and get them to fix it. She still sound rough

[DiscoPol]

Got my 406 checked today. The problem was down to a leaky exhaust gasket somewhere in the engine bay. Its at the upper part of the downpipe and it is a metal gasket. The exhaust specialist didn't have the part for it. So I will have to take it back to a Peugeot dealership who will probably have the gasket and get them to fix it. She still sound rough

at least a gasket should be cheaper than a new front section, as for the suspension issues check out threads on here referring to droplinks or as some prefer to call them chocolate drop links

[LP640]

Hey guys, got the exhaust issues sorted with the changed metal gasket. But now the old girl seem to have developed a new problem. She's beginning to have a lumpy tickover. When I have started her in the mornings, she seems to be somewhat coughing, like there is a congestion somewhere in the fuel system. But when she gets warm, the lumpy and rough idlings goes away. I really have no idea what this could be down to.

And another issue being, that she is seriously down on power. I noticed this when the exhaust gasket was leaking, but even with it replaced, she is still sluggish. With the A/C turned on a hot afternoon, she struggles to pick up any decent speed at all, and at times when I lift off the throttle, when she begins to decelerate, she stalls. She is so sluggish and this is beginning to worry me, paired with the lumpy and rough tickover. Could this be down to a fried cat con that is becoming even more restrictive or could this be a sensor issue? I know she's fitted with all sorts of sensors and a faulty one would be really difficult to pin point. Another thing I would like to add is, if I hold the rev at about 2k RPM, the rpm tends to fluctuate a little and doesn't stay there. Could it be a oxygen sensor that is kaput?

I've made an appt with the local Peugeot dealer in two days time, in the mean time I hope I get to go places decently with her.

[robb]

Hi there LP have a read of the starting and rough running thread thats pinned up third one down on the engine and transmission page