Average Fuel Dilution?

[CarbonSteel]

From a Ford 6.7L point of view, what are you guy/gals seeing for a typical reading? I am seeing 4% to 5% (which I think to be a little high considering the highway miles I run). I had a failed MAF sensor a while back that I thought was the reason for the higher readings, but my last UOA came back at 4%. Before I head back to the dealer, I wanted to see what you guys are experiencing as well as what is the point where I should be concerned?

Thanks for the thoughts.

 

[Eddie]

Blackstone laboratory sets the upper dilution limit at 2.0%. However; I've seen 3% or slightly more on some engines (Honda turbo & Mazda SkyActiv) and apparently no wear problems. I would only be concerned if the wear values in a UOA showed high wear values. Ed

 

[Koz1]

Bio content of Fuel?

 

[CarbonSteel]

Originally Posted By: Koz1
Bio content of Fuel?
<5%

 

[CarbonSteel]

Originally Posted By: Eddie
Blackstone laboratory sets the upper dilution limit at 2.0%. However; I've seen 3% or slightly more on some engines (Honda turbo & Mazda SkyActiv) and apparently no wear problems. I would only be concerned if the wear values in a UOA showed high wear values. Ed
Is it the same for diesel versus gasoline? I was thinking it could be higher with diesel with less of a concern.

 

[dustyroads]

Originally Posted By: 2015_PSD
Originally Posted By: Eddie
Blackstone laboratory sets the upper dilution limit at 2.0%. However; I've seen 3% or slightly more on some engines (Honda turbo & Mazda SkyActiv) and apparently no wear problems. I would only be concerned if the wear values in a UOA showed high wear values. Ed
Is it the same for diesel versus gasoline? I was thinking it could be higher with diesel with less of a concern.


Probably varies by manufacturer. My Detroit DD13 has a warning limit of 7% fuel, but with an older Detroit Series 60 the limit is 2.5%.

I can't help you with your 6.7 Ford, but I had two Volvos with 2-3% fuel dilution. The cause was faulty injector cups (at very low miles) and they were replaced twice under warranty before Volvo came up with a corrected design. A Ford dealer should be able to let their computers load test the injectors in each cylinder for problems. That's all I have to offer.

 

[CarbonSteel]

Originally Posted By: dustyroads
Originally Posted By: 2015_PSD
Originally Posted By: Eddie
Blackstone laboratory sets the upper dilution limit at 2.0%. However; I've seen 3% or slightly more on some engines (Honda turbo & Mazda SkyActiv) and apparently no wear problems. I would only be concerned if the wear values in a UOA showed high wear values. Ed
Is it the same for diesel versus gasoline? I was thinking it could be higher with diesel with less of a concern.


Probably varies by manufacturer. My Detroit DD13 has a warning limit of 7% fuel, but with an older Detroit Series 60 the limit is 2.5%.

I can't help you with your 6.7 Ford, but I had two Volvos with 2-3% fuel dilution. The cause was faulty injector cups (at very low miles) and they were replaced twice under warranty before Volvo came up with a corrected design. A Ford dealer should be able to let their computers load test the injectors in each cylinder for problems. That's all I have to offer.

Thanks Dusty. I guess I will have to take it on and have it checked out. It has been flagged 4 different times (not sequential) for dilution. Perhaps I have a bad injector.

 

[claluja]

< 0.5% for mine.

 

[dnewton3]

5% is the cautionary limit. Not an assurance of harm, but the time to look for escalation of wear.
If the wear metals (rates) are OK, then I'd not worry.
However, I'd not want fuel to go above that during the OCI.
If you're historically seeing 3-5% fuel, and the metals are fine, I'd stick to the OCIs that are giving you the desirable wear results.
If it's the IOLM you're following, then great.

The 6.7L PSD seems to have a fairly large variation of fuel from unit to unit. Not much rhyme or reason to it. Typically lots of idling will cause the fuel up from regens. Why yours is high from good long runs is a bit of a mystery. But as long as it's not harming the wear rates (and it does not seem to be doing so in the least), you'll just have to consider it normal.

 

[mbacfp]

2015_PSD. How often does your truck regen? Mine does it exactly every 500 miles. My Blackstone UOAs have come back < 0.5%, but oil shears from a 40wt to a 30wt pretty quickly which makes me question Blackstone's fuel dilution numbers. Might try a different lab to confirm for myself.

On the 6.7, does fuel dilution numbers come primarily from Regen frequency?

 

[CarbonSteel]

Originally Posted By: dnewton3
5% is the cautionary limit. Not an assurance of harm, but the time to look for escalation of wear. If the wear metals (rates) are OK, then I'd not worry. However, I'd not want fuel to go above that during the OCI. If you're historically seeing 3-5% fuel, and the metals are fine, I'd stick to the OCIs that are giving you the desirable wear results. If it's the IOLM you're following, then great.

The 6.7L PSD seems to have a fairly large variation of fuel from unit to unit. Not much rhyme or reason to it. Typically lots of idling will cause the fuel up from regens. Why yours is high from good long runs is a bit of a mystery. But as long as it's not harming the wear rates (and it does not seem to be doing so in the least), you'll just have to consider it normal.
Thanks Dave. The iOLM has never indicated to change the oil (not sure what its recommendation would be), but 7.5-8K would be "my" OCI limit at present since the dilution is keeping me cautious. The thing that is bothering me the most is something seems to have changed since I had (what I consider to be) decent fuel dilution rates until around 32K on the truck and then things went a bit awry.

The MAF failed during the OCI that had 5% so I backed the OCI down a little to see what would happen to the dilution rates and they went down, but not back to less than 1% as before, although on a per mile basis the last OCI has less fuel dilution than the previous two. I think something is still happening, just not sure what and I suspect the dealer may be the only recourse. Regens on the 6.7L are fairly long (at least on my truck) and I am sure they are contributing, but something sure seems to be "off".


Code:
Vehicle Mileage 44,144 37,027 32,700 26,550 21,330 14,470 10,692 6,234 1,570

Oil Mileage 7,117 4,327 6,150 5,220 6,860 4,018 4,458 4,664 1,570





Fuel Dilution 4.00% 3.40% 5.00% pre>

 

[CarbonSteel]

Originally Posted By: mbacfp
2015_PSD. How often does your truck regen? Mine does it exactly every 500 miles. My Blackstone UOAs have come back < 0.5%, but oil shears from a 40wt to a 30wt pretty quickly which makes me question Blackstone's fuel dilution numbers. Might try a different lab to confirm for myself. On the 6.7, does fuel dilution numbers come primarily from Regen frequency?
My regens are about the same interval (depends on driving conditions of course), and indeed, I believe that regens are the primary source of fuel dilution. I am using Polaris for UOAs (I also never trusted Blackstone's testing methods for dilution) and you can see my dilution rates on the post above.

 

[mbacfp]

My regens last a while too...10-15 minutes I would say. I monitor all the vitals on my Scanguage II. My only thought (not an expert) was your regens were happening more frequently during those high fuel dilution readings. Are your MPG numbers suffering? Hopefully someone else knows more.

 

[Koz1]

If the only thing that changed was a failed MAF maybe the new one is not doing its job properly. Get them to check the voltages. It could be on the line with no code cause it isnt past the failure line. Could the O2 sensor been damaged when the MAF Failed?

 

[Koz1]

Or the EGR.

 

[Bighorn2500]

Have seen 2% on my UAO from Blackstone before, I think Cummins states no more than 5% as well.