Diesel in Oil

[JohnBower]

I probably missed but I'm still confused on how the diesel gets in the oil. I know that there is an injection event that occurs during the exhaust stroke that is used to do a regeneration of the dpf but still don't know how the diesel gets in the oil. Perhaps somebody can elaborate on this.

 

[Mishkaya]

I probably missed but I'm still confused on how the diesel gets in the oil. I know that there is an injection event that occurs during the exhaust stroke that is used to do a regeneration of the dpf but still don't know how the diesel gets in the oil. Perhaps somebody can elaborate on this.

On a common rail, the main causes for fuel in oil are either a stuck injector or a cracked injector body.

Both are bad.

 

[HBarlow]

I have not experienced fuel dilution in the crankcase on my truck but mine is a C&C w/different emissions equipment so I don't have a position on the issue.

A knowledgeable and skilled Dodge-Cummins dealer tech I know has told me with confidence that the oil drains out of the ISB6. 7 very slowly. He thinks that some of the reports of excess oil level result from not allowing sufficient time for oil to drain during a drain. That is his opinion, I don't know if he is right or wrong.

I have never had oil analysis done during over 600k miles of driving three Dodge-Cummins, two of them HPCR engines, so I don't know if they have contaminated crankcase oil with fuel, or not. I haven't experienced any problems.

I wonder sometimes if knowing and worrying too much about details is worth the cost.

 

[Gary - K7GLD]

I wonder sometimes if knowing and worrying too much about details is worth the cost.

Judging by the reports of those with failed turbos (apparently the first casualties of fuel-diluted oil) and failed engines, it just MIGHT be a good idea to watch the condition and level of the oil in the CR engines a bit more closely than on earlier engines - I dern sure know *I* would...



There are a fair number of relatively common failures in various areas and year model trucks that are reported on this board - I may not have personally experienced many of them, but being forewarned is hardly a BAD thing - and may well head off a $eriou$ and unwelcome event...



Try a search on "fuel dilution" over in the 6. 7 3rd generation forum, and get an idea as to what's going on...

 

[Jim W]

I would look at your latest copy of the TDR magazine that has been sent out, this is issue 65. In the magazine in the "Cummins Corner" there is a very good explanation on oil dilution and the change interval for the engine oil required. This is a question and answer column with a Cummins engineer, see pages 42 and 43.

The 6. 7 engine and the emission package will cause fuel dilution, therefore it is imperative that the you change oil when the on board system tells you to.

Just my $0. 02

 

[HBarlow]

Judging by the reports of those with failed turbos (apparently the first casualties of fuel-diluted oil) and failed engines, it just MIGHT be a good idea to watch the condition and level of the oil in the CR engines a bit more closely than on earlier engines - I dern sure know *I* would...

There are a fair number of relatively common failures in various areas and year model trucks that are reported on this board - I may not have personally experienced many of them, but being forewarned is hardly a BAD thing - and may well head off a $eriou$ and unwelcome event...

Try a search on "fuel dilution" over in the 6. 7 3rd generation forum, and get an idea as to what's going on...

Gary,

From the information we've seen since the ISB6. 7 arrived it seems much more likely that the turbo replacements have been due to soot build up that restricts free movement of the VGT rather than bearing failure due to fuel dilution.

I have not heard of an "engine failure" of a 6. 7.

My point is obsesssing over a tiny difference between an acceptable amount of fuel dilution and what might be considered excessive might be better spent reading a good book or going for a walk and changing the oil and filter on the recommended schedule.

My old '01 has survived pretty well without ever having the benefit of oil sampling. I changed the Rotella oil and Fleetguard oil filter every 10,000 miles and ran it hard, "lugged" it up 1000 grades at 1600 rpm and 1300* EGT for 350k miles. I don't know if it will make it to 1,000,000 miles, or not. Don't really care. I always figured oil sampling was more expensive and trouble than simply changing the oil.

Same oil and oil service interval with my HPCR '06 for 230,000 miles only it ran max EGTs of 1425*.

The Cummins engine is pretty hardy as it is.

 

[Austin Diesel]

just a note i have this issue with climbing oil levels in the 08 2500 there are some other threads on this,something to do with egr /cyl. systems washing fuel into crankcase during regens or partial regen.



so all the fancy oil and extra filters like the fs2500 i bought really are a waste of money on the 6. 7 because it wont filter the carbon either so oil is black as night all the time .

But frequent oil changes are a fact of life with this engine. Rotella is working for me and or valvoline true blue



Maybe with the new "AS" flash partial regens will decrease so will oil dilutuion



Any one know if the 10 models will have any revised exhaust revisions ?



Austin Diesel

 

[Gary - K7GLD]

My point is obsesssing over a tiny difference between an acceptable amount of fuel dilution and what might be considered excessive might be better spent reading a good book or going for a walk and changing the oil and filter on the recommended schedule.

WELL, for sure, I'm one of those who probably "obsesses" way too much - I carry a spare VP-44, ECM, and PCM and lift pump - and enough tools (it seems!), to change them all if needed. So far in 65K miles, the only casualty has been that notoriously design-flawed VP-44, with the brass advance sleeve - at about 45K miles. I add lubricity additive to EVERY tank of fuel, and HAVE done that since the truck was new...



THEN, my brother in law with the IDENTICALLY same truck, just gets in his truck, and DRIVES it - yeah, his VP-44 failed too, but at 65K miles - and NO fuel additives, ever!



Go figure! :-laf:-laf

 

[HBarlow]

Gary,

Certainly nothing wrong at all with choosing to be informed. You're probably a meticulous guy who wants to know all the details. You know what the details mean, how they relate, and whether they are truly important or just nice to know.

I think some of the new Cummins owners/TDR members may occasionally become a little too concerned after reading all of the detailed posts with all the information that some members have about their trucks before they have sufficient time and experience to put Dodge-Cummins ownership in perspective.

You and your b-i-l probably provide an excellent illustration. You collect and savor every mechanical detail because you want to know, your b-i-l just drives his because he doesn't wnat to know or doesn't understand. Both of you get similar results.