RockinRob Posted June 7, 2013 Share Posted June 7, 2013 I have e7 460 mack. I have fuel in my oil. A lot of fuel! The popular response from EVERYONE was change your o-rings on your unit pumps. After I changed o-rings on the unit pumps. I drove 200 miles and I have about a gallon of fuel in oil. I took oil pan off and pumped the hand primer to see where it was coming from, but all pressure leaks out when you stop pumping. You would think this would be a pretty big leak and easy to find, but all I can see is a little drip coming down between the end of the steel block and the bottom of the timing cover. I wipe it away and awhile later it is back. You can't see passed the timimg gears so I don't know where it is coming from. Iknow there is a plug in the front of the block ( behind the timing cover ) that is at the end of the fuel resevoir that the unit pumps sit in. Did anyone ever hear of that plug leaking? I think if it is leaking it would be a big leak only when the fuel system is pressurized, like under driving conditions. I checked the fuel transfer pump and its not leaking. I think if I can pressurize the system with air, it will blow the fuel out fast enough so I can see it. Anybody got any good ideas? Anybody ever hear of that plug leaking? This is my first post. Ever. Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/ Share on other sites More sharing options...
br549 Posted June 8, 2013 Share Posted June 8, 2013 Had one do the same thing, replaced unit pumper orings, supply pump, still fuel in oil, it ended up being the plug leaking at the front of block at the fuel gallery. Our never did show leaking under pressure, but when engine is running the heat, vibrations caused it to leak more. Good luck Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-187467 Share on other sites More sharing options...
RockinRob Posted June 9, 2013 Author Share Posted June 9, 2013 Thanks for the for the reply, this is driving me nuts. I guess the hoods coming off, Idon't see a way to check that plug without taking the the front of the truck off. Hood, air to air, radiator etc. Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-187712 Share on other sites More sharing options...
staxx Posted June 9, 2013 Share Posted June 9, 2013 Have had many fuel rail end plug leak. You can usually see a wet spot around edge of front timing cover but not always . Make certain it's not the supply pump shaft seal these fail often also causing fuel in oil, good luck. Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-187740 Share on other sites More sharing options...
41180 Posted June 9, 2013 Share Posted June 9, 2013 i had that happen to my 2000 460xt. it was a bad eup and some how it ruined the cam too Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-187790 Share on other sites More sharing options...
bbigrig Posted June 11, 2013 Share Posted June 11, 2013 I would Drop the pan, apply rail pressure to the fuel system and look up for leaks. Bar the motor over too in case its an EUP leaking at a plunger seal when under lobe pressure from the cam. You will also see if its your timing cover plug leaking into the pan if its dripping from the forward end of the block. Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-188206 Share on other sites More sharing options...
Mackmaster862 Posted July 18, 2013 Share Posted July 18, 2013 We see lots of those plugs leaking have to pull the front cover to get to the plug. Quote Link to comment https://www.bigmacktrucks.com/topic/31481-e7-460-100th-anniversary-fuel-in-my-oil/#findComment-194631 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.