Comparing how companies implement DPF designs
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Cross-Country
Joined: Feb 2019
Posts: 61
Likes: 4
Comparing how companies implement DPF designs
I’m learning more and more about DPF and didn’t realize that manufacturers didn’t do the process the same - specially Ford.
From what I’ve been able to learn GM, RAM, and Nissan all use a “9th injector” that dumps fuel directly into the Diesel Oxidation Catalyst (DOC), while Ford uses a method that dumps raw fuel into engine on the exhaust stroke on all 8 cylinder banks. I’m not enough of a gear head to be able to debate the two designs, but it’s my understanding that by injecting fuel in this manner you run the potential risk of contaminating your oil with diesel fuel whereas using the 9th injector design doesn’t have that issue.
So I guess my question is does doing it “The Ford Way” really open your engine up to potential oil contamination problems later on down the road?
From what I’ve been able to learn GM, RAM, and Nissan all use a “9th injector” that dumps fuel directly into the Diesel Oxidation Catalyst (DOC), while Ford uses a method that dumps raw fuel into engine on the exhaust stroke on all 8 cylinder banks. I’m not enough of a gear head to be able to debate the two designs, but it’s my understanding that by injecting fuel in this manner you run the potential risk of contaminating your oil with diesel fuel whereas using the 9th injector design doesn’t have that issue.
So I guess my question is does doing it “The Ford Way” really open your engine up to potential oil contamination problems later on down the road?
Hotshot
Joined: Nov 2013
Posts: 10,107
Likes: 96
From: Hempstead, TX
I can't speak for the Nissan Cummins, but unless things have changed recently, GM was the only one to inject regen Diesel directly upstream of the DOC. Ford and Ram injected it into the cylinders on the exhaust stroke. Now that GM has the DOC on the outlet housing of the turbo, I wouldn't even swear that is still the case.
Mountain Pass
Joined: Oct 2018
Posts: 112
Likes: 4
Yep. This is why stock Ford 6.7s have a fuel dilution issue. Typically 3-4% fuel in the oil for a typical OCI. This is the main factor limiting oil life in 6.7s. Deleting eliminates the problem, because no more regens, which is when the fuel is dumped in on the exhaust stroke.
If you change your oil according to the oil life meter, you should be ok since fuel shouldn't go above 5% in the oil. But the Ford way essentially eliminates the option of extended oil change intervals (OCIs) for stock 6.7s if you care about your engine. Too much fuel in your oil causes all sorts of problems, including increased wear.
Some problems caused by too much fuel in the oil discussed here:
https://www.lubricants.total.com/fuel-dilution-engine-oil-causes-and-effects
If you change your oil according to the oil life meter, you should be ok since fuel shouldn't go above 5% in the oil. But the Ford way essentially eliminates the option of extended oil change intervals (OCIs) for stock 6.7s if you care about your engine. Too much fuel in your oil causes all sorts of problems, including increased wear.
Some problems caused by too much fuel in the oil discussed here:
https://www.lubricants.total.com/fuel-dilution-engine-oil-causes-and-effects
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Cross-Country
Joined: Feb 2019
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Likes: 4
Yep. This is why stock Ford 6.7s have a fuel dilution issue. Typically 3-4% fuel in the oil for a typical OCI. This is the main factor limiting oil life in 6.7s. Deleting eliminates the problem, because no more regens, which is when the fuel is dumped in on the exhaust stroke.
If you change your oil according to the oil life meter, you should be ok since fuel shouldn't go above 5% in the oil. But the Ford way essentially eliminates the option of extended oil change intervals (OCIs) for stock 6.7s if you care about your engine. Too much fuel in your oil causes all sorts of problems, including increased wear.
Some problems caused by too much fuel in the oil discussed here:
https://www.lubricants.total.com/fue...es-and-effects
If you change your oil according to the oil life meter, you should be ok since fuel shouldn't go above 5% in the oil. But the Ford way essentially eliminates the option of extended oil change intervals (OCIs) for stock 6.7s if you care about your engine. Too much fuel in your oil causes all sorts of problems, including increased wear.
Some problems caused by too much fuel in the oil discussed here:
https://www.lubricants.total.com/fue...es-and-effects
I just purchased this truck used with 20,000 miles on it last December. I don’t have a benchmark to measure against yet, as this will be my first oil sample to send to Blackstone. The dealer had changed all fluids just prior to my purchase.
Assuming similar driving conditions, and in light of the fuel dilution issue stated above, should I stick with 7,500 still or go to 5,000 for this initial analysis? I haven’t done any heavy towing with it yet (just my boat and trailer which combined weigh about 5,500 lbs) and a lot of highway miles, so I’m thinking 7,500 miles - but I really want to get the initial analysis done, especially to see if any fuel dilution. Thoughts?
Mountain Pass
Joined: Oct 2018
Posts: 112
Likes: 4
Reading the Ford diesel supplement it recommends oil changes under NORMAL conditions as 7,500 - 10,000 miles. When I had my Titan diesel, I would send the oil out to Blackstone Labs for analysis. After 3 samples they recommended I change mine every 7,500 (vs the Nissan recommendation of every 10,000) miles, based on my driving conditions. That would have put me at the leading edge of the NORMAL range.
I just purchased this truck used with 20,000 miles on it last December. I don’t have a benchmark to measure against yet, as this will be my first oil sample to send to Blackstone. The dealer had changed all fluids just prior to my purchase.
Assuming similar driving conditions, and in light of the fuel dilution issue stated above, should I stick with 7,500 still or go to 5,000 for this initial analysis? I haven’t done any heavy towing with it yet (just my boat and trailer which combined weigh about 5,500 lbs) and a lot of highway miles, so I’m thinking 7,500 miles - but I really want to get the initial analysis done, especially to see if any fuel dilution. Thoughts?
Don't use Blackstone for vehicles with potential fuel dilution issues, because Blackstone doesn't actually measure fuel dilution - their fuel dilution values are guesses and are usually wrong (google this if you are interested). Use a lab that uses gas chromotagraphy (GC) to measure fuel dilution if you want a real fuel dilution value. Polaris is an example of such a lab (they use GC when viscosity drops more than a certain amount, which means they use GC on most 6.7 samples). Key is you want a GC measurement done on your sample to get a real fuel dilution value.
For example, here are 4 lab analyses on oil from my 6.7:
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4973309/2014-f250-6-7l-amsoil-ss-5w-40-8-800-miles#Post4973309
Cargo Master
Joined: Feb 2015
Posts: 2,338
Likes: 255
From: Livermore Ca.
I never bother with oil testing. I don't understand what the report would be telling me and how important is some of this stuff in the grand scheme of things. To put my mind at ease I only use Motorcraft oils and filters. I also only use full synthetic oil in all my Fords and I have 5 of them.
It is however interesting that Ford dumps fuel into the cylinders on the exhaust stroke which goes into the turbo then to the DPF. It must be ok because my truck with 30.000 miles towing runs just fine. I only change my oil when the truck says to change it. Regens don't seem to be a issue with my truck ether.
It is however interesting that Ford dumps fuel into the cylinders on the exhaust stroke which goes into the turbo then to the DPF. It must be ok because my truck with 30.000 miles towing runs just fine. I only change my oil when the truck says to change it. Regens don't seem to be a issue with my truck ether.
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
I never bother with oil testing. I don't understand what the report would be telling me and how important is some of this stuff in the grand scheme of things. To put my mind at ease I only use Motorcraft oils and filters. I also only use full synthetic oil in all my Fords and I have 5 of them.
It is however interesting that Ford dumps fuel into the cylinders on the exhaust stroke which goes into the turbo then to the DPF. It must be ok because my truck with 30.000 miles towing runs just fine. I only change my oil when the truck says to change it. Regens don't seem to be a issue with my truck ether.
It is however interesting that Ford dumps fuel into the cylinders on the exhaust stroke which goes into the turbo then to the DPF. It must be ok because my truck with 30.000 miles towing runs just fine. I only change my oil when the truck says to change it. Regens don't seem to be a issue with my truck ether.
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Fleet Mechanic
Joined: Oct 2006
Posts: 1,351
Likes: 242
From: North Florida
Because it’s a habit from my 6.0 days, I change oil at 5,000 miles. May not be needed, but it makes me feel good and it’s easy to keep up with multiples of 5. I once tried to go until the truck told me to change it, but got antsy around 6,000 miles and just had to change it.
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