Shoez Posted February 10, 2023 Share Posted February 10, 2023 I have a 2000 CX613 with a 98 E7 460. I was told when I bought it that it had been ReMacked at 1.1, no paper work available. It is coming up on 1.6M. Since I’ve owned it (11/20) the #4 unit pump has had a slight fuel leak. It has been removed/replaced 3 times. We recently replaced the heads and rebuilt the jakes because of an oil leak where the heads meet. After about 2k miles I noticed my fuel mileage had dropped and I was making oil. It is definitely fuel not water getting in the oil. My mechanic thinks he remembers that the head bolts around #4 cylinder had thread dope on them when he pulled them out. We did not use anything on them when we put them back in. I know when we did the exhaust manifold we used thread dope on those bolts as they thread into the oil galley. It is also listed in a service bulletin. Is there any service bulletin that I missed with regards to the head bolts or do I have a much bigger problem. Quote Link to comment https://www.bigmacktrucks.com/topic/72496-%E2%80%9Cmaking-oil%E2%80%9D/ Share on other sites More sharing options...
Mackpro Posted February 10, 2023 Share Posted February 10, 2023 That year model ETECH has excessive fuel from the injectors return back to the tank through passage ways inside the cylinder heads. A leaking top O-ring on the injectors can allow fuel into the oil. Seems likely due to it didn’t start till after the heads replaced. Put some fuel dye in the fuel filters and run the engine for one minute then remove valve covers and use a black light to look for fuel around injector hold downs. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/72496-%E2%80%9Cmaking-oil%E2%80%9D/#findComment-525018 Share on other sites More sharing options...
Joey Mack Posted February 10, 2023 Share Posted February 10, 2023 (edited) I re- built an E-Tech last summer that was making oil.. I took the fuel lift, pump off and put a plug in the output port, and shop air set to 80 PSI in the input port. The fuel in the pump blew out passed the spindle where the gear is.. Bad Pump.. I also found on another one I re- built right after that, and it had a leaking fuel gallery plug, behind the timing cover.. My 2 issues aren't very common in my experience, but it happens. For a bunch of years now, I will remove both the front gallery plugs, and reseal them as part of the rebuild. Good luck.. Jojo Edited February 10, 2023 by Joey Mack Pore cell fone sperring 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72496-%E2%80%9Cmaking-oil%E2%80%9D/#findComment-525022 Share on other sites More sharing options...
Onyx610 Posted February 10, 2023 Share Posted February 10, 2023 You replaced #4 eup 3 times for a fuel leak? Quote Link to comment https://www.bigmacktrucks.com/topic/72496-%E2%80%9Cmaking-oil%E2%80%9D/#findComment-525032 Share on other sites More sharing options...
fjh Posted February 10, 2023 Share Posted February 10, 2023 8 hours ago, Mackpro said: That year model ETECH has excessive fuel from the injectors return back to the tank through passage ways inside the cylinder heads. A leaking top O-ring on the injectors can allow fuel into the oil. Seems likely due to it didn’t start till after the heads replaced. Put some fuel dye in the fuel filters and run the engine for one minute then remove valve covers and use a black light to look for fuel around injector hold downs. If you remove the valve covers and pull the injector hold downs you will see fuel on top of the injector ! this will cost nothing to do just a little time! that way you can confirm what Mack Pro is saying! just remember to torque them back in if you find nothing! Quote Link to comment https://www.bigmacktrucks.com/topic/72496-%E2%80%9Cmaking-oil%E2%80%9D/#findComment-525039 Share on other sites More sharing options...
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