Bigcountry98 Posted February 11, 2021 Share Posted February 11, 2021 Hey guys , I’m new here but i have a problem truck , guess the Mechanics can’t figure it out . Truck is getting fuel into the oil and don’t know where it’s coming from , is there a way to figure this out with out swapping injectors and pumps and hoping that was the problem , i don’t want to dump a bunch of money in it and this is the third time I’ve had it looked at. Any help would be greatly appreciated Quote Link to comment https://www.bigmacktrucks.com/topic/65869-fuel-getting-in-the-oil-on-mack-vision/ Share on other sites More sharing options...
fjh Posted February 11, 2021 Share Posted February 11, 2021 (edited) 26 minutes ago, Bigcountry98 said: Hey guys , I’m new here but i have a problem truck , guess the Mechanics can’t figure it out . Truck is getting fuel into the oil and don’t know where it’s coming from , is there a way to figure this out with out swapping injectors and pumps and hoping that was the problem , i don’t want to dump a bunch of money in it and this is the third time I’ve had it looked at. Any help would be greatly appreciated Buddy what year is the truck? Most common on the Grey engine is Fuel transfer pump Then EUP Orings! Edited February 11, 2021 by fjh 1 Quote Link to comment https://www.bigmacktrucks.com/topic/65869-fuel-getting-in-the-oil-on-mack-vision/#findComment-468791 Share on other sites More sharing options...
Mackpro Posted February 11, 2021 Share Posted February 11, 2021 Pull the fuel supply pump . Check for play in the shaft, should be none. You can spray soapy water on shaft while shooting air into the inlet and outlet abs check for bubbles, other wise here’s what we used to do . Put fuel dye in the primary (first filter) and run the engine for about 45 seconds to a minute. Shut off engine and cap off fuel return line on the side of the block above the air compressor. Hook a air pressure regulator to the inlet of the primary fuel filter inlet and pressurize to 40-50 psi . Drop the oil pan and use a black light and look for leaks. The EUP pumps will always seep fuel to an extent , but not enough between oil changes to cause issues. If you find a EUP leaking, they do make a 3piece lower o-ring for damaged bores . Also there there is a fuel galley plug behind the timing cover that can leak but it rare . 2 Quote Link to comment https://www.bigmacktrucks.com/topic/65869-fuel-getting-in-the-oil-on-mack-vision/#findComment-468821 Share on other sites More sharing options...
R.E.D Posted February 12, 2021 Share Posted February 12, 2021 On my etech ,it was the injector oring that was bad.it would put fuel past the injector hold down cap threads and contaminate oil...you can tell by running engine shortly without valve covers .the culprit injector cap will have less oil sitting on it since the fuel washes it away. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/65869-fuel-getting-in-the-oil-on-mack-vision/#findComment-468829 Share on other sites More sharing options...
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