Anybody try cleaning DPF with compressed air?

[2x6 Bulldog]

I looked at the machines on YouTube that advertise commercial DPF cleaning machines. They simply use compressed air blowing the ash out in a reverse flow from the back of the DPF. I also so people doing it by hand with compressed air and hand nozzle. Looks too easy. I just wondered if anybody on this site ever tried this method and was it successful. If is this easy why not.
I also saw several people use a pressure washer to clean a DPF. I read something about oxidation if water was used and this is not a good idea.
I don't know either way but the compressed air sure blew a ton of ash out. This is the purpose of cleaning. Why or why not? Any DPF engineers out there?
Thanks!

[finaddict]

Don't they cook the DPF in a big oven to some insane temperature prior to blowing out the ash with compressed air?

[2x6 Bulldog]

The machines I saw advertised put the DPF in a box with hole in the bottom connected to a shop vac. A rod would come down with a nozzle on it and randomly spray in each hole. A ton of soot and ash would come out. They would test the clean filter with some gauges on the suction side.
I also saw a guy do it with a hand nozzle. Lots of ash came out.,,,

[aquaman350]

I blew mine out at around 30K with my blow gun and got a big handful of ash. The following few regens were short. I might do it again sometime just to minimize backpressure if not extending its lifetime otherwise. There were several others on this forum who pressure washed their DPF's and had good results.

However, when replacing the DPF with a brand new unit, the DPF learned parameters need to be reset in the PCM. I didn't do that after blowing mine out and it still seems ok and all-normal 18K miles later. Either that or I didn't get enough out to make a difference.

[ford_doctor]

Three things about using compressed air (shop air and a nozzle) to clean a DPF:

1. You need a high volume of air across the entire face of the substrate which pulses to dislodge the embedded ash which cannot be achieved with a small air nozzle
2. You can easily damage the substrate with compressed air by removing the plugs at the ends of the passages rendering the DPF useless
3. Doing so puts you and anyone else in the vicinity of the "cleaning" at risk of breathing in some really nasty stuff. The ash is considered a hazardous material and should be treated as such

Shop air is simply not effective. Baking a DPF is only required when a filter is presented for cleaning that is clogged or overloaded with SOOT or is contaminated with oil or fuel for example. Then it can be cleaned to remove the ASH. A clogged DPF cannot be regenerated on the vehicle nor can ash cleaning be performed until it is removed.

[aquaman350]

I read somewhere no more than 50psi should be applied into the substrate to avoid breaking something. Regardless, common sense prevails as always.

A plugged DPF won't allow a regen on-vehicle since there won't be enough exhaust flow. However, it seems to me one can blow out whatever is in there as a last resort. Enough might come out to allow a regen to take place and spare needing to bake it.

[srjones1]

I pulled mine out about 3 months ago and used a pressure washer to clean it with pretty good results however based on that experience I need to do it again as its running again like it did then. If I pull it out this time it's not going back!

[senix]

I say leave the thing alone if your regens are fairly far apart and you have no issues.

Mine has 77K, unloaded regens around 300-400 miles apart. Towing regens around 130 miles apart on heavy tows.

Sometimes leaving it alone is better.

[rwproctor]

Anyone have issues with the dash message " Drive to Clean Exhaust Filter", not clearing? I have a 2008 F350 with 69790 miles. It regens everyday whithin 5-10 minutes of driving for about 45-60 seconds, usually billowing white, but sometimes a bluer grey. I have driven it 30-40 miles and it wont clear itself.

The whole DPF unit was replaced in Dec of 2011, for a cost of $1300.

Any comments or thoughts?

Rob

[senix]

Originally Posted by rwproctor

Anyone have issues with the dash message " Drive to Clean Exhaust Filter", not clearing? I have a 2008 F350 with 69790 miles. It regens everyday whithin 5-10 minutes of driving for about 45-60 seconds, usually billowing white, but sometimes a bluer grey. I have driven it 30-40 miles and it wont clear itself.

The whole DPF unit was replaced in Dec of 2011, for a cost of $1300.

Any comments or thoughts?

Rob

Sounds like you are either overfueling or eating coolant.

[aquaman350]

I've heard of leaky injectors causing frequent regens. Not sure how to test for it though. A plugged DPF might have just been the symptom rather than the problem.

Fortunately, I think it should still be under the emissions warranty?????

Short trips is killer on regens.... Regens will only start when coolant is above 160F.
On cold days, it takes me at least 15-20 minutes of in-town driving to get that hot and another 5 minutes of regen to heat up the DPF before soot starts burning. My daily commute is 35-45minutes, so I only get about 10-15minutes of DPF burn. I normally need 20-25minutes for a full regen.... Up to 40-45minutes in slow stop-and-go, and about 12-15minutes on straight freeway

Mine belches white smoke for about 1 minute while the DPF is between 500-700F. It smokes easily if it's cold outside and my EGT's and/or CAT temperature are low