I searched on the forum, couldnt find what I was looking for. Ive been following a few threads on Cumminsforum, my question is does the PSD "grow oil" when it regens at idle? I read some Cummins guys were having as much as 2 extra quarts or more of fuel getting into the oil because the truck would regen at idle. I just wanted to know if the PSD had this problem?

 

I know that it was an issue with the 6.4 but I haven't heard about the 6.7 and fuel dilution.

 

Alright cool, cuz thats one thing that was pushing me away from the 6.7 cummins

 

I'm pretty sure the cummins oil growth has nothing to do with regen sicne it uses a 9th injector for that... no chance of that "regen fuel" getting into the oil.

As for the 6.7L Ford, fuel growth has not been reported as an issue on our trucks yet. The new manufacturing tolerances in the engine and new programming have supposedly all but eliminated fuel growth as a concern.

 

Um... thats the Duramax that uses a 9th injector. The cummins only has 6 cylinders, and 6 injectors. The only reason it happens is because at idle the engine isnt making a high enough compression ratio to seal the piston rings and keep fuel from getting past.

 

yeah you're right... sorry, I'm sick today

either way, the 6.7L Powerstroke has not been shown to make much oil at all.

 

Thats good though. My buddy has a '99 7.3, he pretty much changed my mind about the cummins. If i can afford the PSD, id rather have that. It sounds better straight piped.

 

The 6.7 Ford that is...

 

I cant wait to sell my car and buy the new 6.7 PSD.

 

No '08 through '11 Ford diesel does an exhaust cleanout cycle during/at idle. Exception is the ambulance/commercial duty and certain chassis cab configurations.

The 6.4 engine has been known to make oil but is not a condition that applies to every truck. Some do, some don't, and all are advised to change oil at 5K mile intervals just to be sure. 6.4 I had never did.

The 6.7 has not, to the knowledge of everyone here on this message board, had an oil making condition. Most of us so far also do oil change intervals via the PCM oil life indicator which for me nets an approximate 9000 mile interval for oil and filter.

The 6.4 engine is thought to make oil because the regen cycle employs the use of all 8 cylinders to pass unburnt diesel to the DPF, essentially providing a high probability of fuel seepage even in the healthiest of motors. Does not regen at idle though, only in "D" at speed reported over 35mph.

The 6.7 engine only uses one bank of cylinders, 4 cylinders are used to pass diesel to the DPF. Additionally, the engine and DPF design is designed to take advantage of lower temperature "passive" regen MUCH more aggressively than the 6.4. This passive regen does not use diesel in the DPF, just hot exhaust gas. All of this in cumulative effect far reduces the probability of making oil.

It can and probably will happen to someone, these are just engines and things will go wrong. As of yet there is no pattern or concern over the issue.

 

I thought the fuel was only injected into cylinders 7 and 8 and that it was 30 mph not 35?

Anyways to the OP, when you said the PSD sounds better straight piped, forget about that. Unless you wipe your butt with money you probably cant afford repairs on a modern diesel engine thats out of warranty (straight pipe voids warranty). Also, on the 6.4 I've heard a straight pipe doesnt sound any louder from inside the cab and I'm assuming the 6.7 is the same since its even quieter to begin with.

 

These 6.7L engines so far are doing well related to this topic.
I had 5,181 miles on my last oil change with 3.0% fuel in oil.
I've never had the "drive to clean exhaust" message so the regen cycles I do have completed either the first or second time with one per tank on average so about 350 miles.
Based on the 350 miles estimated regen cycles, that's 15 active regen's and I probably have a few more than that.

While I personally think that is a high percentage of fuel, I don't think Ford is concerned.
I don't tow near as much as ruschejj and no matter where I drive, I get stuck at traffic lights (over an hour from I-65) or driving through small towns so that will add to why I need more active regen cycles.
Ruschejj seems to always be moving a trailer so his EGT's are higher and passive regen cycles take care of keeping the filter cleaner.

 

Ford 's resident engineer here stated that 7% was the industry standard for fuel dilution. IMO, anything less than 4% would be excellent performance. BWDIK

It would be interesting to see what fuel dilution levels are being experienced in other brands under similar conditions. Purely speculation here but I would not be surprised to see similar levels from their testing.

Regards

 

Yes, I remember Paul mentioning the 7% awhile back.
You know plenty, BTW.

ruschejj, have you had any oil tests on your 6.7L?

 

Ref the oil dilution in the Cummins the regen cycles used to clean the DPF are only part of the problem, Cummins has and currently still does use add'l injection cycles to deal with the NOX issue where the Duramax and Ford use the urea treatment. The NOX issue is more of a contributing factor than the cleaning of the DPF according to my limited research. This issue was a big factor in my selling my Ram 3500 and replacing it with the Super-Duty...'sides I just look good in a Ford...