Puff of black smoke

[KyleW2]

Looking for some help.
A few weeks back, a friend told me when I punched it on the highway my truck puffed a little black smoke. I had someone else start it while I was watching and there was a light puff (blink and you miss it) out the pipe on start up. I cleaned out the pipe with a paper towel, so far so good..until today. Noticed it again when I started it as there was some black residue on the garage floor behind the pipe.

I do use a bit of oil between changes (Around a quart in 4000 miles). I haven't noticed any difference in how the truck drives power wise. About 2 months ago I got a check engine light which was a gas cap code, so I ordered an OEM cap but by the time it came in the light had already turned off. I went ahead and replaced it since the other one was original. Now I am starting to wonder if the gas cap indeed was not the issue and something else is going on that could link the puff of smoke with that code. Anybody have any ideas on what to check? 2008 Ram with the 4.7

Thanks in advance!

 

[mtnrider]

Could be running rich? Too much fuel, not enough air. What does you air filter look like for starters? Could also be a leaking injector since it's on start up? Also a MAP or O2 sensor causing it to run rich.


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[KyleW2]

Could be running rich? Too much fuel, not enough air. What does you air filter look like for starters? Could also be a leaking injector since it's on start up? Also a MAP or O2 sensor causing it to run rich.


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Could be. Air filter is clean, it is a K&N so when it first happened a few weeks back I cleaned it, it was barely dirty at all even then.

Another thing to note is I have been running Superchips MileageXS tune for a while (over a year now). When it first happened I uninstalled it just to rule it out.

Here is a pic of a piece of cardboard underneath the pipe. This was two starts.
https://ibb.co/8N8mRV7

 

[392DevilDog]

Oxygen sensors.

 

[KyleW2]

Oxygen sensors.

Wouldn’t I get some kind of code if it was oxygen sensors?


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[392DevilDog]

Wouldn’t I get some kind of code if it was oxygen sensors?


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I missed the startup up part. And it looks like you got carbon build up that is breaking loose.

If you can get someone to follow you down the road and see if you get the puff like a diesel when accelerating.

Oxygen sensors are very finicky it is possible for them to send the right codes but not be reading the right information...if you get what I mean.

But if the problem is only at start up...you need to search the methods to remove carbon build up too.

With my V10...spark plugs and o2 sensors have to be changed religiously. Usually when someone asks me if it is a diesel...i know where I am heading the next day.

I just made a quick assumption...but with a scan tool it is pretty easy to watch your 02 sensors and see what they are doing.

Injectors and spark plugs are a bit harder to diagnosis. But they could be the culprit too.

Another issue i had with the black smoke...was the fuel pump was sucking up debris...but never really got to see if that alone was an issue as I changed the o2 sensors at the same time as the fuel pump.

 

[KyleW2]

I am kind of curious if this is related to running somewhat easy on the truck on a 370 mile straight trip (cruise set nearly the whole way at 80 mph) and if when I punched it on the highway (around 300 miles in), it was just blowing out some build up from being run easy.
Either way, I am going to redline it and try to burn some of the carbon buildup off and see what happens. Have to get it inspected this week so I am hesitant to start messing with parts until after then since I don’t have any codes currently.


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[KyleW2]

Got P0456 code again this morning. Same code as last time..changed the gas cap last time. What else could it be?


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[392DevilDog]

Have you checked your EVAP for loose lines or pinholes?

Start at the fuel tank and go forward.

Are you filling the truck while it is running?

 

[KyleW2]

Have you checked your EVAP for loose lines or pinholes?

Start at the fuel tank and go forward.

Are you filling the truck while it is running?

Not filling it while it is running no. Light turned on when I started it this morning, no light when I parked it a few days ago.
I will check for loose lines when I get back to Dallas. Got a 370 mile trip today. Filled up with 89 today to see if running a little better fuel will help with the build up. It didn’t blow anything onto the garage floor this morning so that’s a plus.

I also read that putting some vaseline on the gas cap O ring can help, I’m going to try that as well. Doesn’t hurt.

 

[KyleW2]

Okay so I reset the check engine light 100 miles into my 370 mile trip today, and the light never came back on throughout the drive.

This leads me to believe it is likely not a loose hose, as I would think it would reactivate in 4 hours of driving if so..Went ahead and put vaseline on the gas cap. Going to try to get it inspected tomorrow while it is still off. Last time it took nearly 2 months to turn back on.

I read that a bad purge valve can change the air/fuel ratio as well as throw this code, which might explain why I am getting the carbon buildup issue.

 

[KyleW2]

Inspection passed, Evap system still said Not Ready for it but at least it passed.

All the lines seem to be fine, no weathercracking that I’ve seen. I read that the code is commonly caused by the purge valve or the leak detector pump.

I think I’m going to try the purge valve first and if that doesn’t fix it, then do the leak detector pump. Both parts probably wouldn’t hurt to be replaced anyway.


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[KyleW2]

Purge valve on order, will install it tomorrow.

I was doing some thinking and I remembered two years ago I was pulling a light trailer and got a code which was for an EGR valve. I cleared it as I did not want to deal with it at the moment and this code has never come back on...Fast forward to about 6 months after, the truck stalled on me at a red light. When I started it back up, it revved itself up (to around 2500-3000 rpms) twice - since then no issue. I bring this up as would an EGR valve that is going out/bad potentially cause this carbon buildup? I do notice quite a bit of exhaust fumes when the truck is idling but that has been that way since I bought it in 2015.

 

[KyleW2]

Another update...

My truck usually idles at 600. Lately it will start there but at red lights it will rev up to 800 or so (you can hear it rev itself up). Watching the rpm gauge it will fluctuate between 800 and 900 at lights.

Also noticed that the AC condenser fan is not spinning at idle, causing my AC to go warm at idle. It just so happens both the AC condenser fan and the purge valve are linked to the same harness..

Edit: condenser fan motor just went bad. Replaced it and now it is working like it should. Still waiting for the purge valve..Amazon hurry up!

 

[KyleW2]

Hopefully this is the last update for a while:

New purge valve definitely helped. No longer does the truck rev itself up at idle and it is idling at 600 rpm again. Seems to be shifting better too. Time will tell if it fixed the issue as far as the puff of black and the check engine light.

Will be placing an order at Rockauto soon for new shocks so I'll just order a new leak detector pump and possibly an EGR valve if I have deep pockets that day..both are probably due for replacement anyway.

 

[392DevilDog]

That is all good news. Sounds like you just about got it pegged.

Keep us posted. Hope the truck keeps on trunkin.

 

[KyleW2]

P0456 code is back today. Just so happens it is right after I re-tuned the truck.

Starting to think my truck just does not like the MileageXS tune lol.

 

[CVX20]

Could be. Air filter is clean, it is a K&N so when it first happened a few weeks back I cleaned it, it was barely dirty at all even then.

Another thing to note is I have been running Superchips MileageXS tune for a while (over a year now). When it first happened I uninstalled it just to rule it out.

Here is a pic of a piece of cardboard underneath the pipe. This was two starts.
https://ibb.co/8N8mRV7

There's you problem the K & N is letting all the dirt pass right through LOL.That and the extra oil from the filter screwing up the MAF.

 

[Oliver Closehauf]

Black smoke = unburned fuel.
Blue smoke = oil.
White smoke = coolant.

Sounds like you are getting a fuel dump from the chip since you said it didn't happen until you retuned it.

 

[KyleW2]

There's you problem the K & N is letting all the dirt pass right through LOL.That and the extra oil from the filter screwing up the MAF.

Had not thought about the filter being the issue, but that would make sense. I'll swap it and try that out shortly!