what happens when dpf is cracked

[RGrizzle]

i have read a few threads on various forums about people that say their dealer replaced the dpf because it was supposedly cracked . most people say that the only thing they noticed was that the truck would smoke a little when they got on it and their bumper would turn a little black . they had their trucks checked out because they didn't think these new trucks were supposed to smoke at all . the reason i brought this up is because my truck has always put out a little smoke when i need to get on it . i get just a little black on the truck just above the exhaust pipe between washes but , the truck is white . it has done this ever since it was pretty new (bought in august ) but it runs great , plenty of power , and no lights of any kind (now at almost 8000 miles ). this was the norm on all of the other ctd trucks i had (5. 9's)and this one doesn't smoke anywhere near like they did . i was just curious if this was normal and if it is not , should it be checked out even though it runs so well . i just don't want to rock the boat if this is not a problem because i have had such great luck with the truck so far . fuel mileage hasn't been bad either considering all the dpf and all the horsepower . and also if the dpf were cracked (i don't know that it is), and the truck runs so well , is this necesarily a problem . what do you fellows think . sag2 , maybe you have an idea on this ?

 

[sag2]

If it is cracked you will get smoke. What does the inside of the tail pipe look like? It should be clean with no soot.

 

[RHancock]

with all the problems having one that is cracked may not be a bad thing. .

 

[RGrizzle]

If it is cracked you will get smoke. What does the inside of the tail pipe look like? It should be clean with no soot.

i just went out and ran my finger into the tailpipe and it came out black . there is soot in the pipe . does this for sure mean a cracked dpf ? and if it is will this ever cause any future problems as i have had none yet ? i am not worried about passing an emissions test because there is no testing here not even on gas engines . you have to go into the atlanta area from here to get into emissions testing and then it is only on gas engines . if it is not going to cause me any problems , then i'm not too worried about it but , i don't want to have problems later , maybe even after warranty , and have to pay for something out of my pocket . will it cause any future problems if it is cracked and i let it go or would it actually help the thing if it were cracked like Rhancock suggested ?

 

[Drdorian]

i just went out and ran my finger into the tailpipe and it came out black . there is soot in the pipe . does this for sure mean a cracked dpf ?

Yes, your DPF is cracked. It sounds like it is a small crack, but a crack nonetheless. It may stay that way for a while, but more than likely it will get bigger and you will see more soot.



As for passing an emissions test, that I am not sure... it really depends on what the tailpipe sniffers are looking for. You will be releasing more particulate in the exhaust stream, but at idle (and with the size of your crack) that may be negligible in regards to the test.

 

[jelag]

Opacity - nothing more than a smoke visual test on older cars and a soot test on diesels... . this new test is zero... its like 1/2 teaspoon per mile and a normal 5. 9 produces something like 4-6 tablespoons... . this test with the right equipment will fail the small crack in the DPF and catch the missing DPF... bad on the lungs and eyes... .

NOX - Nitrites of Oxide - damn, spelled it right... by product of high heat in either a gasoline or diesel engine, usually reduced by the EGR system. Doing nothing more than putting an inert gas (read exhaust) back into the combustion during low HP requirements to reduce NOX... Smaller volume of air/fuel = smaller explosion thus less heat..... bad on the ozone... .

Hope this helps... .

 

[RGrizzle]

went to the dealer today and they said nothing was wrong if my truck only smoked once in a while . he said the soot from regeneration has to go somewhere and that was what i was seeing . i don't know what to think but, all i know to do is drive it .

 

[Cavaness]

if something is wrong with it, make sure it is all documented under warranty. those particulate filters are pricey. ($3500?) i think we have only replaced 1 of them.

 

[jelag]

There is not a passage from one side of the filter to the other like a CAT... . The soot will not pass the DPF... but is reduced to about 1:50th of the volume... that is why at some point it will either have to be cleaned or replaced... It's like an air filter but designed to collect soot, burnt to ash and collected... anything on the back side means it's not working and later if this truck has to pass an emission test I'm guessing it will fail. .

I posted a long thread about this filter... it was mentioned above or in another thread that the air at the tail pipe might be cleaner than the air around the truck... this is almost the case...

 

[RGrizzle]

i drove the truck today for a little while and couldn't make it smoke and believe me i tried .

 

[DavidFrench]

Had same problem

My truck smoked white & black. I had all kind of problems with the dpf system. I drove the truck with it smoking until the engine light came on, then went to the dealer and he replaced the catalest. 7K with no smoke and the truck been great.