exhaust blockage

bjc1973 · 09-18-2014, 01:21 PM

had the dpf fault come up on my dash(335d)car felt slightly down on power but not too noticeable.put code reader on car and it came up with quite a few faults,all glow plugs and back pressure sensor to name a few.my pal at the garage said to start by testing glow plugs and glow relay.then move onto other issues and possibly force regen.
dropped the car off a few days later at pals house and when he was taking it up to his garage the car lost alot of power like in limp mode then he said big clouds of smoke came out from the exhaust then it cleared and car revved as normal with power back.but on the floor behind he could see what he described as fibre wool type stuff on the floor(like the sound deadening stuff in exhaust)glowing red like on fire.he drove the car to his garage and car drove well with full power.
he then tested glow plugs which were fine and glow relay was found to be knackered,i know this would stop a re gen.
so glow relay was changed and codes cleared.taken for a drive and re tested for faults.the code reader showed no faults and car drove well.temperature on a run hit 93 degrees,so stats ok.car has now been driven about 100 miles with no power loss and no codes.hopefully issues resolved but my question is what came out of the exhaust and was it this that was causing a blockage and maybe showing dpf fault.cheers for any advice

Hoooper · 09-18-2014, 02:17 PM

I have no idea, but many catalytic converter canisters are lined with flame resistant fibers like fiberglass or asbestos mat. I have not personally ever seen one like that. I think TDI found some of that lining the DPF when he cut it open. Not sure how that could possibly both make it out of the DPF without destroying the DPF, and also make it past the SCR catalyst without destroying the SCR catalyst.

bjc1973 · 10-21-2014, 09:22 AM

car still running fine with no codes but the exhaust tips now are getting sooty quite a bit.also when i put my foot down there seems to be more smoke from the exhaust.is this normal for the diesel as i hadnt noticed it before and the exhaust tips were always quite clean before the issue listed above happened.

TorqueAddict · 10-21-2014, 10:09 AM

There can be a few things leading to this:

- Your DPF was plugged and it cleared itself, and so, you are seeing excessive amount of soot now.

- Your DPF is gone.

i never saw soot in my tail pipes till i had the DPF, only an occasional water/condensation flowing out of tailpipe. You can get your differential pressure checked and that can be used to guess the amount of soot in your DPF. Some of the tools/scanners also have the function to check the soot level.

09-18-2014, 01:21 PM	#1
bjc1973 Private First Class 9 Rep 152 Posts Drives: space grey e92 335d Join Date: May 2013 Location: uk iTrader: (2)	exhaust blockage had the dpf fault come up on my dash(335d)car felt slightly down on power but not too noticeable.put code reader on car and it came up with quite a few faults,all glow plugs and back pressure sensor to name a few.my pal at the garage said to start by testing glow plugs and glow relay.then move onto other issues and possibly force regen. dropped the car off a few days later at pals house and when he was taking it up to his garage the car lost alot of power like in limp mode then he said big clouds of smoke came out from the exhaust then it cleared and car revved as normal with power back.but on the floor behind he could see what he described as fibre wool type stuff on the floor(like the sound deadening stuff in exhaust)glowing red like on fire.he drove the car to his garage and car drove well with full power. he then tested glow plugs which were fine and glow relay was found to be knackered,i know this would stop a re gen. so glow relay was changed and codes cleared.taken for a drive and re tested for faults.the code reader showed no faults and car drove well.temperature on a run hit 93 degrees,so stats ok.car has now been driven about 100 miles with no power loss and no codes.hopefully issues resolved but my question is what came out of the exhaust and was it this that was causing a blockage and maybe showing dpf fault.cheers for any advice
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09-18-2014, 02:17 PM	#2
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	I have no idea, but many catalytic converter canisters are lined with flame resistant fibers like fiberglass or asbestos mat. I have not personally ever seen one like that. I think TDI found some of that lining the DPF when he cut it open. Not sure how that could possibly both make it out of the DPF without destroying the DPF, and also make it past the SCR catalyst without destroying the SCR catalyst.
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10-21-2014, 09:22 AM	#3
bjc1973 Private First Class 9 Rep 152 Posts Drives: space grey e92 335d Join Date: May 2013 Location: uk iTrader: (2)	car still running fine with no codes but the exhaust tips now are getting sooty quite a bit.also when i put my foot down there seems to be more smoke from the exhaust.is this normal for the diesel as i hadnt noticed it before and the exhaust tips were always quite clean before the issue listed above happened.
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10-21-2014, 10:09 AM	#4
TorqueAddict Lieutenant 171 Rep 504 Posts Drives: 340i - 335D Join Date: Oct 2013 Location: Barrie, ON iTrader: (0)	There can be a few things leading to this: - Your DPF was plugged and it cleared itself, and so, you are seeing excessive amount of soot now. - Your DPF is gone. i never saw soot in my tail pipes till i had the DPF, only an occasional water/condensation flowing out of tailpipe. You can get your differential pressure checked and that can be used to guess the amount of soot in your DPF. Some of the tools/scanners also have the function to check the soot level.
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