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White Smoke under hood / Diesel Smell in Cab

13K views 19 replies 5 participants last post by  98whitelightnin 
#1 ·
Hello all,

I have a 2008 Ram 2500 Megacab with the 6.7l engine. Since I bought it last month, there has been intermittent white smoke coming out from under the hood on the driver side, very near where the batteries are. When this happens, a strong diesel exhaust smell comes in the cab, even with the heater/AC OFF.

There is no loss of power. No CEL. Only a "Perform Service" warning on the overhead display console. I have a 75 mile beach trip coming up this Wednesday. Is this something that needs to be addressed immediately?

Truck seems to be running fine otherwise.
 
#2 ·
Hmm, are you deleted? Regen smells like diesel to me, and makes some haze out the tail pipe. I guess an exhaust leak under the hood while in regen could be a thing, just spit balling.

I think the first thing I would do it confirm where the smoke is coming from. That’s gonna be a big help.
 
#5 ·
The truck is 100% stock and has 107k miles on it. All emissions equipment is intact, and no deletes are on it, nor has it had any in the past.

The white smoke is more like a whisp, and not a flurry of smoke. Every time I run and open the hood, the smoke disappears so I can't pinpoint the exact location.

So a possibility is that the DPF needs to be cleaned? Geminijeff76, did you notice a strong exhaust/diesel smell along with the white smoke under the hood?

Would replacing the ccv filter fix the smell?
 
#6 ·
Did you do the 67,500 mile service? It calls for the CCV and a full egr cleaning. The crank case vents into the turbo, so you shouldn’t smell it, but you should definitely do the CCV filter at proper intervals, faster, like every 50k IMO.

I have not read much on “cleaning” the dpf externally. But if you get out on the highway for a good long 45min 65+mph run, that should passively clean the dpf, but really you should be getting messages on the over head or codes about the dpf if it’s getting full.

But seriously, all we can do is take stabs in the dark without more info. Is there codes? Overhead messages? Got to find the slrice of the smoke or haze? All services up to par?
 
#7 ·
I do not know whether the CCV has been replaced, or whether the EGR has been cleaned at the 67k interval, as I bought it last month. The truck is in the shop now, as I did not want to take any chances before heading off to the beach tomorrow. I will post later today with an update on what the shop finds. The shop I took it to is very reputable here in town, and I've had nothing but good experiences with them. They know their stuff.
 
#8 ·
Well, on a side note, if you don’t k ow the history, you definitely want to just do the EGR service (aka 67,500 mile service), it’s pretty crucial on theses trucks that it gets done at proper intervals (imo 40-50k not 67,500). If that egr valve clogs up your in for a works of hurt, dead turbo, dead dpf, lord know what to the engine.


Will that fix for issue? Idk, I don’t think there’s enough information collected yet to determine a possible cause.

Overly diesel smell from the tail pipe is a sign of active regen from what I have seen, a malfunctioning egr would cause the dpf to clog up super fast to the point it’s al
 
#9 ·
Well the shop did a test on the emissions system and found that the EGR bypass valve is leaking. The shop said the EGR bypass valve needs to be replaced. The cost for the part alone is $1,280 with labor costing a little north of $500. The CCV filter needs to be replaced too (they called it the PCV filter on the invoice but I suspect its really the CCV filter. Assuming I'm correct, this is a $50 part that takes 20 minutes to replace. The shop wants $199 plus labor for it.

The cost for the EGR bypass valve is a little suspicious. I've asked my brother in law who owns a clutch shop to make an inquiry to his parts dealer for the EGR bypass valve. I'll be doing the replacement myself.

Either that, or I'll end up deleting the entire EGR system. If this is the route I end up taking, I'm pretty sure I will go with the Sinister EGR delete kit. I just don't know what tuner to go with, to stop the CEL from lighting up every time I start the engine.

EGR Bypass valve replacement video:


CCV filter replacement video:
 
#10 ·
Good glad you spruced the issue.

As far at a leak goes, how could those leak? There so robust, it makes me think it’s just a gasket. The EGR service kit from Genos garage is 100$ comes with all the egr system gaskets, CCV filter and instructions ;)

Edit: mine was leaking one time, but it was out of the crossover tube, it took a new gasket and a new v band clamp to stop it
 
#11 ·
Hmmm thanks for the suggestion to try the EGR cleaning kit from Geno's garage. I was thinking about the bypass valve, and to me, it does not make sense that it would by itself be leaking. Like you said, it has to be a gasket.

I will try the EGR cleaning kit from Geno's. Replace all the gaskets plus the CCV filter. I'll update here on how that goes in a few weeks.

One of the review on the 07-12 EGR cleaning kit page on Geno's mentions that the "back nuts" have to be torqued to 85ft lbs because he was smelling exhaust after doing the kit. Tightening to 85ft lbs fixed this issue. Can you explain where the "back nuts" are, since you have done this yourself as well.

best money saved
Aug 15, 2017 | By Scott
this kit saved me at least $800. It took me about 10 hrs to complete but well worth it. The only thing I would add to the directions is a torque spec for the two hard to reach nuts in the back.. I thought I had them tight but if they are not you will smell the exhaust in your cab with ac on. I torqued mine to 85 ft lbs and that worked for me. otherwise a great kit that saves a lot of money.
 
#12 ·
Hmmm thanks for the suggestion to try the EGR cleaning kit from Geno's garage. I was thinking about the bypass valve, and to me, it does not make sense that it would by itself be leaking. Like you said, it has to be a gasket.



I will try the EGR cleaning kit from Geno's. Replace all the gaskets plus the CCV filter. I'll update here on how that goes in a few weeks.



One of the review on the 07-12 EGR cleaning kit page on Geno's mentions that the "back nuts" have to be torqued to 85ft lbs because he was smelling exhaust after doing the kit. Tightening to 85ft lbs fixed this issue. Can you explain where the "back nuts" are, since you have done this yourself as well.



Yea the back nuts on the cooler are know to be a little bit of a pain, I have taken my cooler off twice now, I didn’t think it was that bad though. People talk about all the contraptions they made up to get them back on on, I don’t get it. I just jammed my arm back there and put it on with my fingers. Laid up on top the motor, left arm went in from behind the cooler to the back right nut. Took me 1 try and just about a minute to do. Getting the right combo of socket and extension length to reach the nut but fit under the cowl was the hard part IMO. As for 85#, I didn’t torque mine, I couldn’t get my T-wrench back there, I just put it on good and tight with my socket wrench and it’s been just fine. You will see leaks easy, there will be black soot blowing out of the leak haha. The rear trick there is to use the new gaskets from the Genos kit, it’s like 4-5 layers where stock was 2 layers. The kit gasket seals up much much better.

Now that I’m deleted, I still decided leaving the EGR system in place was best for me. It makes returning to stock much easier down the road if needed. I just run it “disabled” with the exhaust parts removed/deleted. So a good service and new gaskets won’t h be a waste of your time, even thought I was deleting. I won’t be doing it often though since it’s not even used. So it stays, at least until my stock turbo bites the dust, then upgrade might be in order and the EGR won’t hook up to a 2nd gen swap.

When you do the service, use purple power cleaner, I soaked my cooler and egr valve in purple power for about 12 house, and it came out clean as new when I rinsed it out. I didn’t bother “air blowing it out” first, I didn’t want the soot in the air, I went straight to water hose in the grass to get the loose stuff off then sent it to the purple bath in a bucket.


Ohh also, if the cooler is intact, it’s important that you bleed the cooling system right. There is a “high point” vent coolant riser thing. You can’t miss it. Make sure you squeeze the top radiator hose and get the air out of that vent, coolant should come out when topped off. Then check it again a few days later. Any air in the cooler will make it crack and dump coolant into the exhaust. I’m pretty sure this is the reasons that vent is on there.. ***the vent plug can be very hard to remove, DONT STRIP IT! (personal experience here) it needs heat. I suggest you break it free one day when you just shut down from a full temp drive, then later when it’s cool and you go to service the egr you can get it off. Otherwise use a torch to heat it up.
 
#13 ·
Wow lots of good information s10010001. Thank you! I've decided to leave the EGR system in place for now, and just try replacing all the gaskets with the EGR cleaning kit from Geno's, along with the CCV filter.

I've since gone to the beach and back. Truck ran like a champ. No problems at all, except a crank that lasted 1/2 sec longer when filling up with diesel at the gas station. It did that one more time at the store nearby, and has been fine since. Zero exhaust smell on the way to the beach and back, except when the truck was getting to temp in the morning and at a stop light.

I hauled a truck load of bricks yesterday, and noticed the exhaust smell was considerably worse. It seems the leak is worse when I'm working the engine. This kind of supports a leaky gasket problem. After I dropped the load of bricks off, the exhaust smell went away.

The "high point vent coolant riser" looks like the black pipe sticking out, with the nut/bolt on top of it, right? That is right in front of the EGR bypass valve.

Edit: On Thursday morning, when we were driving to Cape Meares lighthouse, a wisp of white smoke came out the driver side of the hood, near the batteries. At the same time, a strong exhaust smell entered the cab, even with the fans off. This was when the engine was getting to temp and when I was turning the truck around from a "road closed" sign. The white smoke/smell typically never happens when the truck is in motion (faster than 10-20mph).
 
#14 ·
Yea totally sounds like a gasket to me, I’d at pull and inspect. The egr system changes when and how much exhaust gasses it’s moving thru the intake. I’m not really sure the logic on it, but that would like up with the randomness of the smoke.

Best of luck doing your first egr service, it’s fun the first go around, but it’s fairly simple once you do it once. I can have mine off and back on in under an hour now if I need to.

Plan on loosing some coolant. On level ground I lost about half a gallon. Make sure to vent it good when done, you need all the air out of the egr cooler
 
#15 ·
I've ordered the EGR cleaning kit from Geno's garage. Can't wait to get started when the weather is nice and warm, probably in week or two.

The one concerning thing to me though is, when my wife was driving the truck to drop off the kids this past Tuesday, the "wisp" of white smoke became a billowing cloud of white smoke, all emanating from the entire length of the driver's side of the hood. At the same time, the awful exhaust smell entered the cab. The EGR bypass valve as you know, is on the passenger side of the engine bay. My wife said zero smoke on passenger side. She said as soon she pressed the throttle pedal, the smoke disappeared. I've never see any smoke from the passenger side as well.

It's possible that the shop misidentified the source of the leak as coming from the EGR bypass valve when they actually meant the EGR valve, which is on the driver's side of the engine bay.

The invoice from the shop clearly identifies the leaking part: EGR Cooler by-pass valve.

Weird though. The white smoke is on the driver's side of the hood. The EGR cooler by-pass valve is all the way over on the passenger side.

Either way, new gaskets and a new CCV filter will be going on soon enough.
 
#17 ·
Well I started the EGR service yesterday. The EGR valve is disassembled and in its purple power bath right now, and has been in it since yesterday.

I do think I found the source of the smell/white smoke problem and it likely has nothing to do with the EGR system. When I took the batwing shroud off, I noticed that the oil was high on the dipstick. I re-checked 2 more times. The oil is a full 2 1/2 - 3" onto the cable part of the dipstick. Way, way, way above the plastic end that has the "safe" zone on it.

The oil also smells exactly like what I've been smelling in the cab. Not "about the same". It's exactly the same smell, period.

The lady I bought the truck from (her husband owned the truck, and he died a month before I bought the truck) said she took it to have the oil changed before she put it up for sale. The carfax shows this too- she took it to a place called Fast Lane oil change in the first week of February.

So I see the problem now. Fast Lane oil change likely did not let it drain for at least 30 minutes so it's likely 2-3 quarts overfull. I'm going to finish up the EGR valve and the EGR cooler, then do an oil change/new oil filter. After I do the oil change, I'll put the new CCV filter in. I'm pretty confident this will address the smell/white smoke problem.

The EGR valve didn't look that dirty. Soot was in it yeah, but it was not awful. It looked to me that it had been serviced at the 67,500 mark. Nonetheless, I just worked the valve inside the EGR valve, and it moves freely now, much more so than before the purple power bath. It's still in it now. The gaskets when I took them off, looked pretty good too- not what I would expect from originals that had been on there for the entire life of the vehicle. Clearly I won't be reusing those cause they were ripped in half when I took the EGR valve off. New ones from Geno's EGR kit will be going on.

Update: I called Fast Lane and they said they used 15/40W Chevron Delos. They said they have never had to let Diesels sit for 30+ min to drain- said they have 15 years of experience to back this etc etc. Anyway, I'll be switching to Rotella T6 5/40, and doing the change myself.
 
#18 ·
Nice work man, sounds like your on the right path to establishing a solid baseline for your trucks maintenance. Sounds like she’s gonna be a reliable rig. Thanks for following up!

I use t6 5w40 as well, no problems here, but I don’t plan on ding “extended” change intervals, I’ll just do it every 7500.
 
#19 ·
I'm not sure on these Cummins, I have a 2008 cummins as well as an 2011 powerstroke ,but some of the power strokes dump extra fuel in the cylinders to burn out the dpf during regeneration and it ends up in the oil. I thought I've heard of some Cummins doing this too but could be wrong. I'm sure someone will chime in that knows more. But I'm thinking you should dump thar oil immediately and refill with new. As for the white smoke thing, I had similar thing last year on the Cummins and it was a hairline cracked exhaust manifold, ordered a new BD aftermarket 2 piece from genos and it's been great. Just a thought.
 
#20 ·
I agree, I would watch the oil closely and make sure your not filling the crank case with diesel.
 
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