182 blowing exhaust - or is it?

[montana]

​Hi all,

Looking for some advice, I have what sounds like a typical exhaust blow from my 182 however i have examined the exhaust from the backbox to the cat/manifold join visually and feeling for air leaks and come up with nothing.


My first thought was the cat/manifold join (i have replaced this recently) but i now know its not that. Now i am thinking either Inlet Plenum or manifold to engine gasket (this is harder to check).Anything else i should check?


Thanks

 

[Harbinger]

I'd say get someone to rev the engine and listen closer yourself, it's a hard one man job finding things like this. When Ex manifold gasket goes they tend to rattle a little.

 

[montana]

Thanks I will do that

 

[montana]

Well the sound took a turn for the worse yesterday , it now struggles to get above 4k , my guess is still on the manifold gasket ... Any idea how hard this is to change ?

 

[Fred@BTM]

bout 20min

 

[montana]

Thanks Fred, will have a bash later. Is it a case of inlet plenum off for access first ?

 

[montana]

Had the Clio in the air earlier to examine the source of the blow, I had an assistant rev the engine whilst I worked along the exhaust, from the back box to the manifold (under the car and from the engine bay) and there are no leaks.

So decided to take the inlet plenum off and have a nosy , apart from the 3 plugs from the right being much looser than the 4th one , the problem is still there ( thought I had fixed it with the looser plugs)

Upon refitting I am sure the engine sounds quieter but I still have some symptoms;

- holding back across the rev range
- strongish fuel smell from under the bonnet & exhaust tips. Not sure if this is normal.
- increase in noise , slightly more rasp.


I am now thinking some kind of cat failure , so will get that off and have a look.

Any input ?

Cheers

 

[montana]

Still chasing this, had the cat off and inspected the internals and it looks good as new

 

[Harbinger]

You sure the cat is on properly, stand well back and take a look at it from the side, is it hanging down at all? have you bought a new clamp and what sealant did you use for the cat to Centre? Ideally you'd want a new Cat fitting kit after taking it off too, or just decat the thing and be done with it.

 

[montana]

You sure the cat is on properly, stand well back and take a look at it from the side, is it hanging down at all? have you bought a new clamp and what sealant did you use for the cat to Centre? Ideally you'd want a new Cat fitting kit after taking it off too, or just decat the thing and be done with it.

Yes it's straight to look at. I replaced the cat to manifold kit and heavy duty clamp previously when it was blowing slightly. Sealant I used high temp stuff on the cat to centre section join.