my truck went on limp mopde

ponyboy · January 10, 2013

hey guy im a diesel tech i did what i said ill never do i bought a 6.4. i got a smokeing deal on it had two melted pistons i rebulit the short block and replace one head and rocker arms and injectors i have about 6k on it now and it has never realy felt right i can tell when its in regn i can fell like a sight missand in the last week it set off the check engine light for the dpf being pluged i ceel the light and comes back on with in a few days but today it went in limp mode good thing i always have my ids with me got the code for engine oil over fill i ceel the light and drove home i was checking power balince and my #7 cly is +20 and number 2cly is -20 and fuel trim is +18 and -15 at idel what you guys think i should check?

Keith Browning · January 10, 2013

Adjust the oil level then perform a manual compression test. Then find out why the oil level is too high - fuel dilution is usually caused by the HPFP leaking or an injector body/fitting.

Steve Mutter · January 11, 2013

Don't forget to check the fuel rail pressure sensor too. Had one leak thru the sensor.

ponyboy · January 11, 2013

i check my oil first thing today and my oil is low but my dpf needs to be replace any one know a place to sent it out to get clean out?

lmorris · January 11, 2013

Only places I know that do them are heavy duty truck repair shops, mostly dealerships, try local heavyduty truck dealers in your area.

mrbudge · January 11, 2013

A heavy truck DPF is a cartridge, looks like a giant air filter. They fit in a DPF cleaner with adapters and are cleaned with compressed air, with the ash vacuumed away. Since the light truck DPF is in a welded unit, I haven't been able to find any places that will clean them. The cleaning process an a filter that is not contaminated with oil, coolant, or fuel is just a flow test, then blow out the ash with compressed air from the outlet side, then another flow test to verify the result. They also watch for damaged filter cells while cleaning. If the filter is contaminated they bake it first, then clean it. I have been tempted to do a backyard cleaning on a 6.4 filter (leaf blower, or equivalent) that isn't contaminated, but haven't had the opportunity yet.

Aaron · January 12, 2013

A heavy truck DPF is a cartridge, looks like a giant air filter. They fit in a DPF cleaner with adapters and are cleaned with compressed air, with the ash vacuumed away. Since the light truck DPF is in a welded unit, I haven't been able to find any places that will clean them. The cleaning process an a filter that is not contaminated with oil, coolant, or fuel is just a flow test, then blow out the ash with compressed air from the outlet side, then another flow test to verify the result. They also watch for damaged filter cells while cleaning. If the filter is contaminated they bake it first, then clean it. I have been tempted to do a backyard cleaning on a 6.4 filter (leaf blower, or equivalent) that isn't contaminated, but haven't had the opportunity yet.

Jim will be chiming in shortly with the Mexican Manual Regen.

Jim Warman · January 12, 2013

Didn't work on the kids truck Posted Image

But it has worked in something less than 50% of the (not too many) efforts.

We looked at all the options (bear in mind my son doesn't buy much of the diesel he uses so consumption isn't an issue - and he is smart enough to avoid idling when possible) and replaced the DPF.

Reasons.... I have a grandson. I can continue to assume the moral high ground on emissions controls. It isn't against the law. No aftermarket electronics or gewgaws required. The original DPF lasted almost 300,000 kms. Most importantly - I consider myself a professional technician - had I done anything to defeat or modify this vital emissions control, I would have abdicated my right to call myself a professional.

A clean environment doesn't come cheap - BP proved that.

Aaron · January 12, 2013

50% of the time, it works every time Posted Image

Our DPF trucks beat up filters BAD at work.

The DPF/SCR trucks aren't bad on DPF's but they eat urea at a rate of about 5 gallons every two days.

ponyboy · January 13, 2013

man this thing went on limp mode on me agen today i check the oil and its low but it gave me the code for oil over fill agen but its not but my dpf is done i just been too busy fixing other people trucks i havent't had time to work on my own but i deen to im getting a lot of like back pressure out the intake i can feel it in the throttle and have intake nose

Aaron · January 13, 2013

That's really not good if it's putting compression out the intake...

Pretty good indication of a valvetrain failure which is becoming pretty frighteningly common on these... Real frightening, since I have one in the driveway.

Jim Warman · January 14, 2013

Every time I've heard a 6.4 sound like a 7.3 with a bent push tube (we call 'em 'helicopters'), I've put a camshaft in.

cbriggs · January 17, 2013

The oil overfull code comes from a calculation of unmetered fuel source entering the engine. If the engine has a tonne of blowby, it could explain the oil consumption, and the excess crankcase vapours could give the oil overfull code.

I did an engine on an 08 recently, that was down into the low 200's on several cylinders, and high 200's on the rest. Ran remarkably good, started good cold, but burnt 10 liters of oil every 2000kms.