Help with diagnosis please: 6.7 Cummins, new turbo, intermittently blowing blue smoke

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mrldcty

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2007 3500 dually, 6.7 Cummins, 135K miles: Last year my turbo went out so I did some research and replaced it with an ATS Aurora 4000. I also did an EGR cleanout at that time. It was quite a tussle getting it in and out, but once it was installed, it ran awesome for a few months. Loads of power, mileage was up, and I was a happy camper. At the end of the summer, I was stopped at a stoplight and noticed blue smoke coming from under the right side of the engine compartment. I jumped out to have a look but by the time I got it in park and the hood up, it had stopped. It continues to get worse, and happen more often but I haven't been able to diagnose where it is coming from. I'm hoping someone on here can offer some suggestions on what it might be. Here are some other observations/thoughts:

1. It's blue smoke, so my first thought was oil leak. I tried tightening the fittings that I can get to without removing the intake and battery. I got a small turn on one of the banjos, but everything else seems snug. Also, it's not down on oil. Oil pressure is good.
2. There is black soot in various places on the passenger side of the engine, but nothing that would indicate where it is coming from.
3. Truck sounds and runs great, tons of power and not getting hot. Starts right up.
4. No codes are being thrown, at least as far as my ODBII reader can tell.
5. Sometimes it smokes like crazy and other times nothing, which makes me wonder if it has something to do with the EGR cycle.
6. My mileage seems to be inching down. While experimenting with gearing, I have noticed that it gets better mileage if I run it at 2000 RPM or above. Like 2 miles/gal better! Is this normal? Or perhaps the ECU calculates mileage incorrectly when running in lower gears than the auto trans would?
7. If I stop and I see it smoking, if I put it in park, it stops. I have tried leaving it in neutral and even in drive with the brake on, but I can't seem to get out there fast enough to catch it in the act... so strange! I even had a buddy drive it with me as the passenger and when it smoked, I jumped out and still didn't catch it. Other times, I think... oh it will stop, but it smokes and smokes until I try to look at it. It's as if it's messing with me! Is there some ECU controlled cycle that would sense when it isn't under load or in P or N that could explain the intermittent nature of the smoke?
8. Exhaust connections seems solid and the air filter doesn't look particularly fouled or black (I changed it recently).
9. Longer freeway drives seems to reduce the frequency and volume, but this is really anecdotal evidence because it may smoke a whole bunch while on the freeway and get blown out the back such that I don't notice it. I haven't noticed any smoke trailing behind the truck when in motion, but it may be that it simply isn't enough to see.

I don't think the dealer will touch it now that I've put an aftermarket turbo in it. Does anyone have a recommendation on diagnostic devices to help figure this out? I suspect my OBDII reader may not be giving me all the codes.

Also, if anyone knows a reliable diesel mechanic near North Bend WA... I'm all ears.

Thanks in advance for any suggestions!
 

Choupique

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Well the short answer is that soot=exhaust leak, somewhere. Clean it all off and pay close attention to where it shows back up.

Have you modified the crankcase ventilation setup at all? A real diagnostics check would help to see if the engine has logged any crankcase pressure faults, EGR temp delta faults, stuff like that which may or may not trip the CEL.
 
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mrldcty

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OK, thanks for that. I will have to remove the intake and battery to really clean it well. And while I'm at it, have a better look around. I would not have thought that blue smoke would come from exhaust... could the soot simply be oil burned by the exhaust on that side? Plus I haven't noticed any increase in, or net new, noises. Just spit balling it...

WRT the crankcase ventilation... I replaced the filter and haven't otherwise modified it. Wouldn't EGR temp data faults and the like appear as codes in the OBDII stream? Or is there a diagnostic device available to consumers/DIYers that could help?
 

Choupique

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Something like an OBDlink 2 Will read pretty much anything.

If you think you have oil leaking on the hot side of the engine you have a legitimate fire hazard and need to sort it out without driving it too much if possible.

I just checked and there isn't anything in the 6.7 troubleshooting manual for blue smoke.
 
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mtnrider

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Are you losing (burning) any oil? Have you checked for excessive blow by (remove the oil fill cap when running).

.
 

Dennis Shellito

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Have you changed the crankcase filter inside the top half of the valve cover? A clogged/soggy CCV filter could cause what you are experiencing.
 

Choupique

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If you buy an OBDlink 2, it has a nice free companion app available that will read, as best as I can tell so far, every code and PGN there is on the CAN network.

I bought alfaOBD when I bought my LINK2 and found out after that I could have read everything with the OBDlink app. Just something to consider. I could have saved myself 50 bucks for what I needed.
 

BWL

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I wonder if it's a small leak on the turbo bearings that's getting worse. Would be more noticeable at idle than under load if that's the case or you're flooding them using the wrong sized orifice on the supply line with the new turbo or the oe line was re-used and it's been a little oil starved causing premature wear. The guys on the cummins forum would probably have more insight.
 
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mrldcty

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To circle back, I think I have found the issue after removing the air intake piping and battery/tray. One of the nuts holding the turbo to the exhaust manifold is missing and it is very black right behind it. I've been trying to remove the turbo oil feed line to get better access to the stud to replace that nut but I'm afraid I'm going to twist off the tubing as the nut won't come free of it. Anyone know a decent online place to look up parts? Both mopar sites I've tried to use (mymoparparts.com and store.mopar.com) are pure crap.
 

MJCs18Diesel

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I just changed my CCV filter today. It is easy to do. First, purchase a 6-point deep 1/4 drive 8mm socket to help with the back left two screws under the cable holders. The filter is recommended to be change at 60K mile mark. The brand name ones are expensive, but the more inexpensive filter I found is the Dorman 904-418 filter. The factory original filter I removed was a Fleetguard 54003 filter. I took my time and it took about an hour. The left rear connector was easy to remove once I slid the red safety key to the left. And, remember to spread a little oil around the three round seals.

NOTE: After I put mine in, I did a Google search and found filters ranging in price from $30 - 148 for a Mopar filter, and they're $104 at Geno's. How do you know what you are getting for $30?
 

06 Dodge

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My self I would buy the Fleetguard CV52001 for $73.06 at Amazon, I trust Fleetguard over other brands...
 

Travelin Ram

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Sounds like you have found the exhaust leak. I expect there’s a correlation between more frequent smoking episodes and regen cycles. Could be your DPF is getting coked up. More regen means worse fuel economy and it fits with your observations.
 

KoboldTaco

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Sounds like you have found the exhaust leak. I expect there’s a correlation between more frequent smoking episodes and regen cycles. Could be your DPF is getting coked up. More regen means worse fuel economy and it fits with your observations.
I recall his rig was before def and DPF filters so there will not be a link.
 

mtnrider

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I recall his rig was before def and DPF filters so there will not be a link.

Nope, all 6.7's have a DPF and EGR, and 13+ also added the SCR and DEF on top of that.

.
 
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