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Can anyone tell me if the exhaust is fitted with a DPF or a similar version of a DPF or catalytic converter that can get clogged up and cause a poor engine performance issue like low power and black smoke?

 

Vehicle is a 2006 fortwo Diesel

Edited by Johnnynumberfive

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Welcome and yes the exhaust has a 8" long CAT within it that can get clogged. The holes are so small it's rediculous....!    Some take this item out.....but it may smell a bit while sitting at an idle at a light depending upon the tune of your car.  So I'm told...lol.

 

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Black smoke is usually too much fuel or not enough air.  Look for a wastegate that is stuck partway open or a holed intercooler first.  Either condition will kill power.  Also check the rubber hoses between the turbo and the intake for rub through and that they are in place. If that checks out you could take the muffler off and go for a drive and see if there is a huge difference in performance.  Did your problem happen all of a sudden?  
Let us know if you find your problem.

 

Nigel

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Black smoke is usually stuck EGR valve on a Smart 450 Cdi. 

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2 hours ago, tolsen said:

Black smoke is usually stuck EGR valve on a Smart 450 Cdi. 

Hmmmm.....Nigel....?

 

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Are you telling me to clean mine?  It’s only been a coupe of years.

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4 hours ago, Nigel said:

Are you telling me to clean mine?  It’s only been a coupe of years.

I saw the black smoke remember, maybe, could be...it wasn't this bad last year I'm sure.

 

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No DPF on Canadian ones; they're only EU-3.  I've never heard of a cat getting clogged on one and certainly in 400,000 km on my own cdis, I've had no issue with that.

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I removed a CAT that was basically clogged and you couldn't see through it even with strong flashlight....I kept the CAT pieces for a while , then discarded them after looking at them for months on end.....taking up space....dirty things....must go....lol.

I've also seen mufflers with so much soot inside them it took way too long to bang it clean before i could weld it back up.  Not sure how they ran except for the split lower seam.

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Thanks guys for the info so far!!!!!

 

I should have mentioned that I just bought the car this month with the engine performing poorly for a good deal. 

Also should have mentioned that it smokes at idle and throughout RPM range with engine loaded or not so I don't suspect turbo system (intercooler, hoses wastegate etc)

In park when I press on gas pedal WOT I can barely get rpm up and in gear I can barely drive over a cigarette butt from a standstill.

 

I tested injectors for proper misting and flow and they are fine. I will perform a cylinder compression test and remove exhaust this weekend and recheck. 

Thanks again and please keep any other info you can think of coming.

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Inter cooler has rub through holes in it I bet and the EGR is plugged solid......bets anyone...?

Is there any bars showing on the dashboard...?  Sounds like the 3 bars of death as they call it..?

Is there a large oil stain on the differential or around the inter cooler etc etc..?

 

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My advice is to do the easy checks first.  No need for oscilloscope. 

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What are the three bars? 

I haven't noticed, will check though

no oil anywhere on Diff

I already checked my waveform for my injectors and entered them in my scopes database but i always like to compare to others or known good ones. seems normal though.

 

 

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The three bar show up where the dash shows you what gear you are in or where the lock out key is shown.....right in the middle of the cluster.  There will be 3 bars ilistrated vertically. Limp mode basically.

 

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