Oil Dilution with noisy high pressure fuel pump

[tcosman21]

I received my oil analysis back from the Amsoil affiliate oil analyzer company, my oil dilution was terrible. I’m reading through some similar threads and I’m requesting what some owners did to combat the fuel in the engine oil that was successful. I run Amsoil signature series 5W-30 with their oil filter and change at 7.500 miles since I bought my Mav with 14k miles, currently has 46k. I don’t tow much with this vehicle and my Maverick spends 90% or more commuting on the interstate. What concerns me is interstate driving should help burn that fuel out of the oil. Mine is not. I’ve already concluded I’m changing engine oil at 5k moving forward, and switching engine oil to Penzoil full synthetic and using the Motorcraft FL-910S oil filter. Before my next oil change, I’m changing at 4.000 miles and conducting another oil analysis. Any other recommendations are appreciated in solving this issue. I also plan to take it to the dealership.

Thank you!

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[todd92]

What do you do before changing the oil? Fuel dilution happens during cold start and short trips. I change my oil myself and pull into my garage after a good drive to get the oil hot then let it cool prior to changing the oil. No dilution.

 

[grumpyunk]

The report indicates you may have fuel being mixed with the oil. I would check the high pressure fuel pump for leakage. I would also check the PCV system to be sure it is venting crankcase gases to the intake. The cam follower of the high pressure pump has direct access to the crankcase, as does the un-pressured side of the pump, such as a diaphragm. A compromised diaphragm could leak fuel into the crankcase.
If you have a 'catch can' connected, I would check what it has in the canister. If there's a lot of liquid, it could be contributing to the vapor load even as it collects liquie.
A compression test could be done to rule in/out excessive blowby.
Are you getting appropriate fuel mileage? In my driving, the current tank is around 29mpg. I try to keep the trips on the longer side than 2 mile runs to the grocery store. My goal minimum is a 10 mile one-way, 20 round trip to minimize oil contamination, and evaporation of any blowby condensates.

 

[Snox801]

I would definitely not change from amsoil. Amsoil SS has one of the highest ratings for handling fuel dilution. Meaning they can have much higher fuel dilution and not cause wear. That was the main reason I ran it when I got ecoboosts.
First thing you need to do is run several tanks of shell or other high quilts fuel. Shell has been seen to have the highest detergent package. It actually can mess with some tuners files. Add in a bottle of fuel injector cleaner with those.
Dirty injectors can have an effect on dilution also.

 

[Snox801]

What do you do before changing the oil? Fuel dilution happens during cold start and short trips. I change my oil myself and pull into my garage after a good drive to get the oil hot then let it cool prior to changing the oil. No dilution.

It doesn’t happen that fast. I’ve posted my oil analysis a few times with lots of short trips and oil changes. I’ve done the changes with all kinds of different methods. It’s never came back high dilution

 

[Bob zimmerman]

I’ll keep this as short as I can.

I understand your oil dilution problem. 100%
I own a 2017 Honda CRV. That engine had such bad oil dilution that there was a class-action lawsuit against Honda. The attorneys got the most out of the deal and we got an extended warranty on the engine but no solution. I had/have up to one quart of gas in the oil. It shows on the dipstick. And my oil goes from new to black as coal even after an fresh oil change.

I live in the same city as Amsoil’s corporate headquarters. I spoke with their engineers about my oil dilution back in 2017 and they were rather alarmed at the amount of oil dilution. They are well aware of what is happening out there.

Black stone does a terrible job at showing oil dilution and for that reason I will never waste money with them again. I had severe oil dilution and their analysis showed only 3% dilution. Apparently they used a flash test to see the temp at which the oil would catch fire and did some fuzzy math to determine dilution.

Bottom line, I still have the CRV and I have 80k miles on it now and it still runs but it is a defective engine and Honda knows it. But they had better Attorneys. You can google the lawsuit and all the issues if you are bored. Good luck.
Bob

 

[tcosman21]

What do you do before changing the oil? Fuel dilution happens during cold start and short trips. I change my oil myself and pull into my garage after a good drive to get the oil hot then let it cool prior to changing the oil. No dilution.

I normally change it within a half hour after returning home from work when it needs to be changed. The time it takes me to prep the oil change and put coveralls on.

 

[tcosman21]

Everything is factory on my Maverick pertaining to the drivetrain. I’m averaging 28-30.5 MPG by calculating it manually, not by the cluster. This has been steady MPG leading up to there oil analysis. This is also my first analysis done, followed the instructions as it was written.

I did notice the high pressure fuel pump being a little more noisy compared to when I first purchased the pickup in Feb of 2024. The performance still feels right, but I’m pondering if the lag when in town driving contributes to the fuel/oil issue.

 

[HotRod Junkie]

I second the idea of staying with Amsoil

Also , I would up the viscosity without hesitation.. 5w40 or even 5w50 is warranted in this case and also you might want to change it even more frequently than 4K

I see alot of UOA's from these trucks and the common theme is fuel dilution from the DFI

 

[tcosman21]

I would definitely not change from amsoil. Amsoil SS has one of the highest ratings for handling fuel dilution. Meaning they can have much higher fuel dilution and not cause wear. That was the main reason I ran it when I got ecoboosts.
First thing you need to do is run several tanks of shell or other high quilts fuel. Shell has been seen to have the highest detergent package. It actually can mess with some tuners files. Add in a bottle of fuel injector cleaner with those.
Dirty injectors can have an effect on dilution also.

I only run “Top Tier” gasoline in this Maverick since I purchased it. I did run the fuel injector cleaner and upper cylinder lubricant within the last two months as a preventative maintenance.

 

[Tbone289]

The good news is that your wear metals are very good. I would be most concerned about the 100 degree kinematic viscosity being lower than the 5w-20 range.

I second the suggestion to up the viscosity to a 5w-40, and move to a shorter (4K) oil change interval. You also should have the HPFP and injectors checked for leakage.

How about the oil level in the sump? Do you see it change (rise or lower) over the oil change interval? It appears you didn't add any from the report.

 

[Tbone289]

Black stone does a terrible job at showing oil dilution and for that reason I will never waste money with them again. I had severe oil dilution and their analysis showed only 3% dilution. Apparently they used a flash test to see the temp at which the oil would catch fire and did some fuzzy math to determine dilution.

Blackstone's method of testing fuel dilution isn't the best, but I wouldn't call it a waste of money. While they may not show a 100% accurate fuel dilution level, the factors that are affected directly by fuel dilution such as increased wear metals, kinematic viscosity and flashpoint are accurate.

 

[Tbone289]

I’ve already concluded I’m changing engine oil at 5k moving forward, and switching engine oil to Penzoil full synthetic and using the Motorcraft FL-910S oil filter.

A quick comment on this... I wouldn't suggest using Pennzoil Platinum 5w-30 in your case. It is lower on the kinematic viscosity scale than other 5w-30 full synthetic oils, so if you decide to not move to an oil with a higher viscosity rating (5w-40), there are better options such as Quaker State and Mobil 1.

 

[Snox801]

I first must also state I think in your case I would also run the 5w50.
I also can’t get behind the blackstone test being not worth anything. How is that poster testing his oil dilution? He states he has severe dilution but how do you know the percent without some kind of test?

Looks like OP had the basics covered. I think you just need to go thicker oil and more frequent. Based on lack of wear metals I would do 5w50 and change at 5k.

5w50 because that is what for recommends for the mustang track pack 2.3 and it’s very common in the 2.0 st world. I run it when it’s very hot and I’m hauling in the summer months with my previous ecoboost. Not yet with this one but my reports come back very good so far

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