cracked exhaust but no unusual noise

[wemorgan]

Whilst changing the Smart car's spark plugs I notice a crack in the exhaust pipe:

the crack looks substantial, but yet the exhaust sounds the same as normal. It has also recently passed its MoT. Is this anything I should be worried about or should i just wait for a more audible change before replacing it?

Thanks.

 

[Will]

Hard to tell from the photos and I'm not at all familiar with Smarts, but it looks as though the crack is blowing (as you'd expect) where the sooty deposits are opposite it.

How many lambda probes does the smart have, and where are they/it located in relation to the crack (I can see one on the top photo). Ie, could escaping exhaust gasses confuse the fuelling by under-reading? Is this exhaust piece just a silencer?

If you're keeping it I'd definately replace it as it'll need doing at some point anyway

Will

 

[wemorgan]

How many lambda probes does the smart have, and where are they/it located in relation to the crack (I can see one on the top photo). Ie, could escaping exhaust gasses confuse the fuelling by under-reading? Is this exhaust piece just a silencer?

As far as I can make out there is a lamda sensor down stream on the crack within the silencer, as shown in the 3rd photo here.

Evilution - Smart Car Encyclopaedia

I think I'll keep my eye for a second-hand exhaust on Ebay as some owners do like to upgrade to aftermarket performance ones.

 

[NormanC]

I think that the thing you have to worry about is exhaust fumes being dragged into the car. It's much more difficult to smell a modern petrol exhaust (unlike oil-burners!!) but the fumes are still lethal.

Please make sure that you protect you well-being!!

 

[bouncer]

With a crack like that it will be drawing in air, your fuel economy will see a change. It's a stress fracture and will only get worse, and may fall off leaving you stranded.

sTeVe

 

[Bellow]

Will, I am currently in similar situation to you. Severed within the mounting flange, only noisy for first couple of minutes from cold. Removed to return for repair and Lambda sensor and exhaust internals very sooty - like your plugs...
Currently the standard pipe is back on the car and when Digitec returns, it will be interesting to see cleanliness of Lambda sensor on re-replacement.

 

[Bellow]

More to the point though, if/when yours breaks right through, there wont be much left holding the exhaust on. Only the bracket over on the left side of it. You will end up stranded!
In the interim, I would recommend getting some releasant into the Lambda sensor. You will need it for your next exhaust, and they are a pain to remove.

 

[alexander patie]

an easy repair surely? just needs welding.

 

[Bellow]

an easy repair surely? just needs welding.

Was wondering the same. Exhaust is stainless I think, so would need TIG, but not rocket science.
Would save having to remove Lambda sensor...

 

[wemorgan]

Thanks for the tip re. spraying the lamda with releasant spray, I'll also do the manifold bolts too whilst I'm there.

Does anyone know rough costs to expect for the welding?

 

[bouncer]

Lambda sensors come out a lot easier when the system is cold, use the correct tool because they have easily damaged internals.

sTeVe

 

[Ian B Walker]

Does anyone know rough costs to expect for the welding?

If its stainless and the unit is off the car I think you should get change out of £15.

 

[wemorgan]

I went for a new exhaust in the end. Thanks Jay for doing me a very good price.

Old and new exhaust:

New exhaust in situ