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AlmostAnOldGuy's avatar
AlmostAnOldGuy
Explorer
Jun 16, 2015

Gas Direct Injection & Oil Change Interval

I have run a couple of Blackstone reports on my oil from the truck in my signature. No issues, metals look fine, but the fuel dilution is up to 2.3% and there is a related drop in viscosity at 5,000 miles. I have a short commute to work and that may contribute to my fuel dilution. Again, they report no issues but recommend continuing the oil changes at 5,000 miles. This is what I had planned on, oil for this rig is cheap.

For what it is worth the standard oil change interval is 10k and the oil life indicator reports around 50% at 5k miles.

For those who are now driving Gas DI engines this is something to be aware of.

Overall I have been happy with the performance of this engine and my goal is to keep it well maintained.

Good luck all,
Stu

p.s. When I am out of warranty I will be adding a catch can as well to help keep the intake valves cleaner.
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  • AlmostAnOldGuy's avatar
    AlmostAnOldGuy
    Explorer
    Jun 16, 2015
    ktmrfs wrote:
    naturist wrote:
    I believe gas engines typically require a "rich" fuel mixture for warm up, so perhaps your short commute for work is the culprit here. I also know that a lot of short trips is bad for all IC engines, regardless of fuel type for a number of reasons.


    the two cars in my post mentioned above are mostly short commutes especially in the winter, and yet blackstone shows no fuel dilution after 7500 miles.


    Let me clarify I am referring to Gas Direct Injection, GDI. I went back and updated the title of the thread.

    Thanks,
    Stu
  • ktmrfs's avatar
    ktmrfs
    Explorer II
    Jun 16, 2015
    naturist wrote:
    I believe gas engines typically require a "rich" fuel mixture for warm up, so perhaps your short commute for work is the culprit here. I also know that a lot of short trips is bad for all IC engines, regardless of fuel type for a number of reasons.


    the two cars in my post mentioned above are mostly short commutes especially in the winter, and yet blackstone shows no fuel dilution after 7500 miles.
  • AlmostAnOldGuy's avatar
    AlmostAnOldGuy
    Explorer
    Jun 16, 2015
    naturist wrote:
    I believe gas engines typically require a "rich" fuel mixture for warm up, so perhaps your short commute for work is the culprit here. I also know that a lot of short trips is bad for all IC engines, regardless of fuel type for a number of reasons.


    Yes, I think this is a contributor as the fuel does not get the opportunity to 'cook off' when the engine is running cold. I was speaking with an aircraft mechanic (A&P) who told me older radial engines would dump some fuel in the oil when they shut down to reduce the viscosity for easier startup. The fuel would then burn off when the engine was started again and was run at operating temperature.

    The reason I was looking in the first place is from various posts I have seen on other forums from folks running gas direct injection engines (various makes) noting some level of fuel in the oil.
  • naturist's avatar
    naturist
    Nomad
    Jun 16, 2015
    I believe gas engines typically require a "rich" fuel mixture for warm up, so perhaps your short commute for work is the culprit here. I also know that a lot of short trips is bad for all IC engines, regardless of fuel type for a number of reasons.
  • ktmrfs's avatar
    ktmrfs
    Explorer II
    Jun 16, 2015
    I seem to recall that ford is/was having some issues with fuel dilution in the oil on some ecoboosts.

    That does sound high. On my 04.5 duramax at 10K miles blackstone shows no fuel dilution, same on my 97 Mercedes E420 at 7500 miles and my 97 Mercedes SL500 at 7500 miles.

    With fuel injection fuel dilution shouldn't be an issue anymore. You might want to do some checking on possible TSB's from ford on the ecoboost for this.

    DI engines in theory should have less of an issue with fuel dilution than any other injection since fuel is metered into each cylinder individually. Even port injections can have fuel cross flowing between cylinders since the fuel is going to the intake manifold. so cylinders could be running rich or lean under certain conditions. And since it is high pressure it vaporizes quickly as well.

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