Question for the DURAMAX guys

j-ten-ner · February 25, 2012

For work I drive a F350. Yeah yeah I know...but I have to.

At least once a day a message (on the DIC) will show up: "cleaning exhaust system/filter". So far so good.

When that happens the engine is running shitty. The rpm goes up and down even while driving and the sound of the engine is awful and some times the truck smokes like hell.

Once in a while the message "drive to clean exhaust" appears. The message stays on for a long time. Since I've got the truck I managed only once to finish the cleaning cycle only 'cause I'd to drive to Whistler for work.

After the long drive the DIC showed "Cleaning cycle completed".

Do I have to drive the truck around the block for 2 hours to clean the exhaust? What is the purpose of an exhaust cleaning system when I have to run the engine for hours?

You guys have the same shit going on with the DURAMAX?

Oh and of curse the dealer says: "That's normal...".

so long

j-ten-ner

becker87 · February 25, 2012

Thank the EPA for that. I don't drive i diesel so I have not experienced it personally but from what I have heard that is normal, depending on how long the interval is between cleanings. And I do believe during it's "regan cycles" you are not suppose to turn the truck off.

kstruckcountry · February 25, 2012

It's normal. I've seen tons of videos of it on YouTube. I don't know if gms are the same, but I don't remember seeing any of em. It is a really counterproductive system. Seems like the EPA is trying to kill the diesel engine. If I ever end up with a new truck that has it (wishful thinking) I'd definitely look into urea system delete.

markw8 · February 25, 2012

The Ford seens to be more of an issue than the Duramax. Long periods of idleing can cause it. If you have the owners manual it will explain it. As the particulite filter accumulates soot at a certain point it has to be burned off. At that point extra fuel is injected to raise the temperature enough to burn the soot out. Idleing and short trips won't allow a proper regen. It takes 20+ minutes of steady driving above 40-45 or so to complete the cycle.

Mark

Mike74 · February 27, 2012

It is normal.... What happens is the filter in the exhaust (Diesel Particulate Filter, DPF) captures the particulates that are in the exhaust. Once the filter reachers a specified level, the computer senses it and increases rpm's to heat up the exhaust and burn out the particulates. This will usually be accompanied by white smoke. Once the level goes down, the cycle is over. Thats why they tell you to run them on the interstate to burn them out if you can. Also, if you dont get it cleaned out enough over a period, they will clog and its about 2 grand to replace....ask me how I know... All diesels have it now on all brands. GM has an additive you have to add as well.

oversteer · March 3, 2012

From the 2012 Duramax manual (page 9-12):

"The DPF will clean itself as part of normal operation. Several factors including fuel consumed, hours of engine operation and miles driven are monitored by the Engine Control Module (ECM). The self-cleaning occurs approximately once per tank of fuel."

...

"Under certain driving conditions, such as stop and go traffic, the filter cannot clean itself."

...

"For the filter to clean itself, the vehicle must be driven above 50 km/h (30 mph) until the CLEANING EXHAUST FILTER KEEP DRIVING UNTIL MESSAGE IS CLEARED message goes off. The will take about 30 minutes."

cfeiring · March 3, 2012

In the 3 plus years I have not had a single problem with my DPF. It works seamlessly as far as I am concerned. I do note the fuel burn during a regen as the mpg will be noted to be lower during a regen cycle. But other than the reduced fuel mileage on my truck it is hard to note when the truck enters a regen cycle.

Compared to the ford that is mentioned above, my guess there is a problem with that truck, but I do not own or drive a ford with a dpf.

j-ten-ner · March 4, 2012

Yes there is a problem. And the dealer doesn't seem able to fix it. Or better, the problem occurs shortly after we got the truck back. Every time.

It happened to my co-workers trucks too. Maybe it is just the specific model or year they were build.

I mean, what is the idea ( I know...less pollution etc.)?

Who in the real world has the time to drive around the block 'til the cycle is done? And it seems kind of strange to produce new particles to get rid of the old ones...

When your truck is in the regen cycle is he smoking so badly too? The exhaust at the Ford is on the passenger side. I have to go off the pedal when I pass a bus station with people waiting.

I think sometimes that less is more.

so long

j-ten-ner

Diesail · March 5, 2012

I have also been driving a duramax for 3+ years with a DPF and not once have I seen this message. They ONLY time I am aware of anybody seeing on a duramax is when they are running a dirty tune on a programmer and still have a dpf.

pwall · March 5, 2012

I've never noticed the regen cycle on my truck. Works flawlessly in my opinion.

j-ten-ner · March 5, 2012

i should have talked my boss into buying Chevys. But it's to late. He ordered new F350's already...f&^%($^k!

so long

j-ten-ner

nitemare17 · April 2, 2012

they should do like International does and just have a have a "park regen" switch so you can set it and forget it when it needs to be done

ChaseN · May 11, 2012

the ford you're driving has an EXTREMELY old program on the PCM. it needs to be updated. I am new to GM, but had 4 6.4's and 3 6.7's.

Ford only regen's while driving, while GM regens at idle or driving. GM does not let you know when it is doing it, it just does it.

ChevyTech77 · May 11, 2012

GM does not regen at idle unless forced with a scan tool or manual switch on the medium duty trucks.

ChaseN · May 12, 2012

When i said i was new to GM, i meant my 1500, not dmax by any means. I see you're a certified tech, but something must be wrong with all of my trucks then. Running a fleet of 30+ Duramax's, All mostly 2012's and they regen during idle. They are only 3500's, not medium duty. Guess I'll be calling my dealer and getting them all to the shop asap!! Even the few 08's I had in the past regen during idle.