Ive got an 06 5.9 cummins auto, owned it for a little over a year now.   First 5k miles, it used a little bit of oil, maybe top of safe to middle section, so lets say 1.5 quarts?.  I have a leaking front crank seal(only visible oil leak), so I assumed it to be that.  I didnt care, wasnt using enough for me to worry at this point.

Previous owner had no issues, and was using Lucas long drain 15w-40 synthetic.  I changed the oil back in april to Rotella T6(5w-40) since the lucas stuff wasnt available in the area I lived.  Truck started mysteriously consuming more oil, no leaks visible anywhere on engine.  I havent done a proper compression check on it, but the ones you can do in your garage(oil cap test, and checking crank case breather), and both of those check out, no smoke, no air bubbles, and this is with a hot engine idling at 1500rpm.

I have fulled the charge air cooler boot in front of the turbo and it's bone dry.  Engine has amazing power, and starts in -30C degree wheather with no block heater without a problem.

Towards the end of the summer, I started loosing a lot of oil. maybe 2+ quarts every 500 miles.  The only thing I've noticed with the increase in oil consumption is that when I hit the accelerator with the window open it stunk like rotella t6 from the engine compartment(not the exhaust), a really strong smell of it.

 

With that said I can only assume I would see blue smoke with that much oil consumption if it were rings?  I have a turbo back exhaust so there no cat to catch any form of smoke. 

 

I spoke to the cummins tech at the dealer and he mentioned trying using 15w-40 Valvoline Premium Blue, which is the original oil for this engine, and run it for awhile watching the oil level before coming in for any expensive tests.

I have so far put on 150 or so miles and havent seen the oil level go down noticibly, my only concern with doing this is that I'm now running a 15W oil when temps can get below -30 here.. so I'm expecting to see harder starting this winter..Thinking of getting an oil pan heater, but I would much rather fix whatever is causing the oil consumption and go back to the 5W oil...

 

I've also checked the coolant for oil, and it's clean.

Transmission fluid is also clean

 

Any ideas as to what the problem is?  My only recourse at this point would be a compression and leakdown test in the event that the problem really is rings without smoke... or could I just be losing THAT MUCH oil from my front crank seal?  

 

Additionally the only problem I have had with the engine so far is that one day it threw a hole bunch of codes at me, FCA circuit open, fuel rail pressure too high, the limp mode code and #1 cylinder misfire. It turned out that the FCA wiring harness had come lose somehow, so I cleaned the contacts, and plugged it back in, did the same with the valve cover gasket wiring harness, I shot some electro contact cleaner in there and plugged them back in.  Those codes to this day have not come back, but during that time the engine ran like a bag of crap and belched out smoke like it was running on super overfuel, not sure if the smoke was blue or black, as it didn't last for more than a minute or two.

Edited December 23, 201311 yr by Joe989

I dont know why he said to switch from one dino oil to another. They are pretty much the same. I would pull your downpipe off your turbo and see if you are leaking oil past the turbo into the exhaust. I have seen that a couple of times. If that isnt it, compression check.

Rotella T6 is a synthetic, and premium blue is dino.

 

Wouldnt oil in a down pipe be burned off as white/grey smoke, same as dropping oil on a manifold?

I'd believe it could just be the difference in oils. At one job I had running heavy equipment they used Co-op oil and some dozers burned a fair bit. One operator started running a different brand ( I believe Penzoil ) and his oil consumption nearly disappeared.

I missed the t6 and only saw rotella. Anyways i have seen syn. burn more than dyno. I personally dont like syn and dont see any advantages of running it. I tried it in my wifes jeep and i constantly smelt burning oil and would actually leak oil. Switched back and never smelled it again. As far as the turbo leak and smoke, just depends on the amount of oil. Where he isnt losing much it could be possible.

I'd believe it could just be the difference in oils. At one job I had running heavy equipment they used Co-op oil and some dozers burned a fair bit. One operator started running a different brand ( I believe Penzoil ) and his oil consumption nearly disappeared.

 

I do believe that the Cummins tech was thinking this same thing. I think I'm still gonna get a compression check done, so I can stop worrying if I'm gonna have to sleeve my cylinders or not lol.

I missed the t6 and only saw rotella. Anyways i have seen syn. burn more than dyno. I personally dont like syn and dont see any advantages of running it. I tried it in my wifes jeep and i constantly smelt burning oil and would actually leak oil. Switched back and never smelled it again. As far as the turbo leak and smoke, just depends on the amount of oil. Where he isnt losing much it could be possible.

 

Well cold starts in canada are the advantage.  Any place south of North Dakota I would say you're wasting money.

Im hoping its just that.

Thing is I didn't smell burned oil, I just smelled oil, and all I smelled from the tail pipe was burnt diesel.  The smell has pretty much stopped, so I'm not sure if it was the rotella brand just being smelly, or if the thicker oil isn't leaking out... wherever it was coming from.

I just put T-6 0W-40 in my 24 valve. I'll be watching for oil consumption.

Valvoline makes a Premium Blue Extreme that is designed for lower temps. It is possible to put oil out the turbo and not get any smoke/smell. Rotella is known to stink, so that may be nothing.

Valvoline makes a Premium Blue Extreme that is designed for lower temps. It is possible to put oil out the turbo and not get any smoke/smell. Rotella is known to stink, so that may be nothing.

but that much oil?

ROSMELLA?  I will always use Valvoline. right now i have 5-40 in for winter. come summer it back to 15-40 fleet something... it's cheep.

 

as for the leak. how much oil is covering the from axle? maybe post up some pics. if you have a tuner, keep it off see if your smoking under heave loads or acceleration. that's when i would think its going to blow smoke the most.

ROSMELLA?  I will always use Valvoline. right now i have 5-40 in for winter. come summer it back to 15-40 fleet something... it's cheep. as for the leak. how much oil is covering the from axle? maybe post up some pics. if you have a tuner, keep it off see if your smoking under heave loads or acceleration. that's when i would think its going to blow smoke the most.

hah yeah.Zero oil on the axel, biggest amount of oil is on the front of the oil pan by the dampener, the bolts are wet with oil and theres a bit on the pan, I have however never seen oil spots on the ground. Theres also a tiny bit of oil on the inspection plate of the tranny bellhousing but not enough for me to suspect a rear seal especially since the bottom of the truck is dry. if i took pics you woulnt see much...theres also no tuner on it, but i know this truck has changed hands a few times so i cant say if it never has.. but it only used oil roughly 8 months after i bought it and im pretty easy on it.

ROSMELLA?  I will always use Valvoline. right now i have 5-40 in for winter. come summer it back to 15-40 fleet something... it's cheep. as for the leak. how much oil is covering the from axle? maybe post up some pics. if you have a tuner, keep it off see if your smoking under heave loads or acceleration. that's when i would think its going to blow smoke the most.

There is a little bit of smoke just before the turbo spools. you wouldnt really see it unless youre looking. my girlfriend said that she saw greyish smoke when i go up hills towing the camper. she was in hr car behind me. the most oil loss was actually when we drove out west about 450miles, the truck was unloaded. thats pretty much it for smoke.

I honestly would never run anything less than a 10w oil in a diesel unless it is designed to run it like VW, The issue may be coming from the 5w you were using.

 

I use Amsoil and it is just as bad if not worse than Rotella as far as smell goes, It ususally smells very strong for about 3-5k miles before it simmers down, even the ATF does the same thing, can smell it for a couple months after doing a tranny service.

 

What does your air filter and intake look like? I hope you don't have a K&N r some other cheap media filter on it that would have dusted the engine like a friend of mine did this year  with an 03 CR. I believe he had an AEM Brute force intake and filter.

Edited December 24, 201311 yr by Wild and Free

Valvoline Premium Blue has a pretty good smell to it also.

I honestly would never run anything less than a 10w oil in a diesel unless it is designed to run it like VW, The issue may be coming from the 5w you were using. I use Amsoil and it is just as bad if not worse than Rotella as far as smell goes, It ususally smells very strong for about 3-5k miles before it simmers down, even the ATF does the same thing, can smell it for a couple months after doing a tranny service. What does your air filter and intake look like? I hope you don't have a K&N r some other cheap media filter on it that would have dusted the engine like a friend of mine did this year  with an 03 CR. I believe he had an AEM Brute force intake and filter.

the intake on mine is stock. i looked into it abd saw no advantage to running anything else. A friend of mine uses 10w-30 in his. which is a nono the viscosity is too low. but its his truck. the thing with the oil smell was that it only stank towards the end of its life. not the begining.

10-30 is not too low of viscosity at all for a diesel.  100% of all CAT heavy mine and construction equipment comes from the factory with 10w30 and that is what all CAT dealers put in when they do services.

10-30 is not too low of viscosity at all for a diesel.  100% of all CAT heavy mine and construction equipment comes from the factory with 10w30 and that is what all CAT dealers put in when they do services.

yeah but cummins says a 40weight is required. I dunno.

yeah but cummins says a 40weight is required. I dunno.

 

Cummins actually has criteria for acceptable 30wt oils in the ISB, I have ran a 30wt and didn't like the UOA so I stick to 40wt.

Cummins actually has criteria for acceptable 30wt oils in the ISB, I have ran a 30wt and didn't like the UOA so I stick to 40wt.

ahh had no idea. still think in my situation a 30 weight oil would be too thin

what those checked then i'd be doing a compression check then. maybe have your injectors flow tested as well. valve adjustment...