Fuel in oil

[DBradham]

OK I know there has been alot of talk about it and up until now I have had no problems (2008 3500 6. 7 megacab)untill now. I did notice something that started happening the same time the oil level started to climb. When using my exhaust brake(sliding vane turbo) I noticed that the turbo would spool up when I let my foot off of the peddle... the exhaust brake would let you know it was doing its thing but the turbo would start to whine indicating a "boost" to manifold pressure. This did not happen for the first 22000 miles. Wouldnt the computer... sensing a boost in manifold pressure want to inject more fuel to balance the Fuel/Air ratio... and you dont need it if you are taking your foot off the peddle so oil dilution happens. The turbo will not spool up when letting off the peddle with the exhaust brake NOT engauged. I know the exhaust brake is just a sliding vane inside the turbo so could this be the problem... . A bad turbo or a flash problem. The way I drive the truck has not changed since I bought it new so why all of a sudden the problems and why do I get boost when in an exhaust brake slowing down situation?

 

[HBarlow]

I read your post twice but am not clear. How do you know the turbo is "spooling up"? Do you have a boost gauge?

The ECM controls the position of the turbo as well as fueling UNLESS, possibly your turbo is dirty (sooted) and is binding. A fellow member described this, I think it was MMullenax. If the turbo is sooted and binding then the turbo can't "obey" the signal from the ECM and the ECM may be confused because it "thinks" the turbo vanes are in the position ordered but are not and different results are occuring.

 

[Hoefler]

The turbo even in braking mode is still producing boost. With the exhaust restricted, there is no place for the exhaust to go, and builds pressure that is backed up to the intake side. The pressure build up and will be noticed on the gauge. I noticed this when I installed my gauges at 250 miles, and is considered normal. I have seen as much as 7lbs of boost. If you have a pyrometer ( EGT ) installed, you will notice that there is a drop in temperature will braking confirming there is no fueling while braking or deceleration even in regeneration.

 

[sag2]

A couple of things. First, if it was adding fuel the truck would want to speed up, not slow down, even with the brake on. This would be similar to the trucks (5. 9 or 6. 7) that had a debris stuck injector, and when you lifted the throttle the truck still wanted to keep accelerating. Second, the ECM always knows the position of the nozzle, hence all the codes when they do stick from soot. If the nozzle is not where it is commanded, CEL. Without looking at the turbo speed on the scan tool there is no positive way to determine if the turbo is spooling up now but was not before.

Did you make a change to the air filter? Different filters may change the sound of the intake.

 

[MullenaxM]

You might want to check for a exhaust leak at the back of the EGR cooler.





Mike

 

[DBradham]

I guess i feel better... . just trying to figure out WHY i now have fuel in my oil that was not there untill 22000 miles. If fuel is being dumped at a rate that cannot be fully burned ... washing down the cylinders... and diluting the oil... why is the truck not "speeding up"? our bogging down do to an overly rich fuel air mixture? I put Amsoil in everything i own but cant afford to change my oil every 3000 miles with synthetics$$$$.

 

[Austin Diesel]

Fuel in Crankcase and Texas Diesel Truck Emissions Inspections





The fueling problem persists on my 08 6. 7 also just running rotella and have a FS2500 remote filter that cost 45. 00 to replace plus primary filter and thought i could extend oil change intervals with this filter then found out that the carbon particulates are to small for the filter to pick up. And the fuel issue oil samples show viscosity will go critical if left beyond 7000 miles , Amsoil is great but until regens cease it washes fuel into crankcase through EGR system and oil levels climb . Cummins says its acceptable so does dodge . Ford has same issues ,now you are faced with 100 dollar plus oil changes at more frequent intervals or switching to cheaper oil . I use rotella or valvoline and oil samples are basically the same analysis. And hope to trade this truck off when better technology comes down the pipe line as i am to poor to alter exhaust beyond a muffler delete and duals and void my warranty . but have my old parts saved for reinstallation as or if needed.

I have always been a hot rodder by heart and would drop smog stuff from this machine at the drop of the hat . But i am restricted by my payment book,bills, and resalabilty and dealer warranty service for now and thankful that i have a new truck that i thought i would not have to work on. Now i am a unofficial cummins diesel tech .



"AS" Flash on 08 truck and all is well for now.



Now i hear that Texas will start diesel Truck Emissions Inspections next year dont know if they will sniff exhaust but if components are missing then it will or could fail so camolflage or altered ,aftermarket ,dummy or hollow DPF and CATS will probally start showing up in place of complete removal to get around state inspections if possible .

I know they sniff all exhaust and hook up computer emmissions reports in all major metro texas citys now for cars and print a report for EPA compliance.



Austin Diesel

 

[Austin Diesel]

I guess i feel better... . just trying to figure out WHY i now have fuel in my oil that was not there untill 22000 miles. If fuel is being dumped at a rate that cannot be fully burned ... washing down the cylinders... and diluting the oil... why is the truck not "speeding up"? our bogging down do to an overly rich fuel air mixture? I put Amsoil in everything i own but cant afford to change my oil every 3000 miles with synthetics$$$$.

Welcome to the Fuel in oil club. Ive been complaining about this since new and have noted this in oil samples and in my dealer service logs also.



Just wonder how much bearing life and cylinder wear is increased. Factory says just change your oil more often $$$$. Only way to measure is to tear down engine and mike the clearances. Sure this issue was not addressed in original engineering production protocals.

 

[tempforce]

i have had the dealers mark down on the service order every time i'm in for a oil change. that the oil level is way above the normal line on the dipstick. i change the oil every 5,000 miles. if anything happens it will be documented, and the replacement engine will be under warrenty. if it dies before the warrenty runs out.

after the warrenty runs out. the common rail computer for a 5. 9 will be running my replacement 6. 7. sure it will be derated, and make more noise. but all of the extra junk won't be on the engine or exhaust either.

i would hate to go back to the old turbo, and have to buy a computer for the transmission. but if thats what it takes after the warrenty is expired. then it will happen.