Joey Mack Posted June 18, 2022 Share Posted June 18, 2022 Hi guy's.. So I was given the task of finding out how the oil level rose up due to diesel in the crankcase.. I got this job after a few other issues occurred. I learned that it was smoking heavy, so they replaced the injectors. Well I found out yesterday , when I pulled #6 injector due to low temp on the cyl. by 50 degrees, it was rusted and not new... and a newbie was doing the repairs with no real guidance.. and he doesnt speak English.. I asked about the EUP's? The owner said #3 broke a bolt and moved.. new bolts but no new orings.. Ok, so I go back to that EUP, pull it and re-ring it.. They run the truck for part of the day, and oil level is 1" over full. So they give it back to me... I re-ring the other 6 EUP's and then check fuel pressure.. I did not check fuel pressure first, for my own reason's.. When I check fuel pressure, it is 125 PSI.. Today I changed the oil and filters, set the level to the full line, and put a new 60 PSI regulator on it.. I ran the engine and fuel pressure was almost 70 PSI.. No sweat.. So tomorrow they will run the truck to see how it does. I couldnt drive it for an hour, because I am building an ASET-C as well, and they didnt want me riding around... . So my question is... Barring a major issue like a crack somewhere.. How else could the crankcase get diesel contamination.. I figured the high fuel pressure was pushing it passed the lower EUP o-rings.. I don't get stumped often, but on this one, because 2 people were on it and one cant speak english.. I don't have the whole story.. I pulled the valve covers and ran the engine and watched the injector plugs for leaks and they were good. ok.. I will stop here and wait for some other ideas... Thanks guy's, Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/ Share on other sites More sharing options...
Joey Mack Posted June 18, 2022 Author Share Posted June 18, 2022 Shoot, I forgot to say, it is NOT smoking... Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500534 Share on other sites More sharing options...
steeler Posted June 18, 2022 Share Posted June 18, 2022 The only 3 things I've run into over the years are eup's, injector caps, and fuel pump seal. Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500538 Share on other sites More sharing options...
Joey Mack Posted June 18, 2022 Author Share Posted June 18, 2022 yep, and the pump is good, EUP's are re-ringed, and the EUP bores were good, as far as injector caps.. no leaks, I ran the engine up to temp with the valve covers off, and saw no fuel bubbling around the caps... I hope the new regulator that dropped fuel pressure from 125 PSI to 70 PSI, is the fix.. This engine is not smoking, it was just raising the oil level with diesel.. We'll see.. I will keep posting.. thank you for responding... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500539 Share on other sites More sharing options...
fjh Posted June 18, 2022 Share Posted June 18, 2022 Joe if the engine is NOT CCR the Injector top Oring on the injector can let fuel into the heads Seen this happen as noted ! You may not see it unless you pull the caps! Also running that high of fuel pressure may have compromised The fuel pump Seal new or old! Just sayin! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500575 Share on other sites More sharing options...
Joey Mack Posted June 18, 2022 Author Share Posted June 18, 2022 Thanks 'F'.. I pulled the fuel pump and put shop air to the inlet and capped the outlet. i adjusted the shop air down.. there was no air leak. so I figured it is good.. I actually did this last week on an ASET-C, and the pump seal bled air like a stuck pig.. i took that pump apart to find the impellor was grinding into the housing.. That engine got 'washed'. I am currently rebuilding it.. Same customer, 3 different units put fuel in the crankcase in 2 weeks.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500590 Share on other sites More sharing options...
Joey Mack Posted June 20, 2022 Author Share Posted June 20, 2022 Well, today I pressure tested the fuel galleries and there was no 'leak down' . then I pressure tested the return ports in the heads, no (leak down).. I pulled the fuel lift pump off again and tested it too.. no leaks. I pulled the injectors just because,,,, and there was a little rust in the #6 injector bore, and that cylinder was also running 50 degrees cooler than the other 5. The owner told me today that the issue started shortly after his mechanic replaced the injectors due to heavy smoke coming out of the stack. So I pulled the heads, i will continue tomorrow. It's funny how they had 2 trucks and an excavator, get diesel in the oil, in a 2 month period.. Dumb luck I guess.. I welcome any thoughts/ opinion's/ and guidance... I am still scratching my head on this one.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500766 Share on other sites More sharing options...
fjh Posted June 21, 2022 Share Posted June 21, 2022 Buddy My thought here is that transfer pump ! bench testing is not a reliable test in my mind ! As the engine is not tuning the shaft ,Static the shaft may not leak but turning it and any gear vibration may change your scenario it may leak ! Just sayin! Ya the fact that three machines in a week is suspicious !but at this point I can't connect any dots myself! Hope fully you fine some cracks in the heads but its a long shot! That said was the bore on number 6 injector pitted from rust and not sealing!? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500832 Share on other sites More sharing options...
Onyx610 Posted June 21, 2022 Share Posted June 21, 2022 (edited) 3 hours ago, fjh said: Buddy My thought here is that transfer pump ! bench testing is not a reliable test in my mind ! As the engine is not tuning the shaft ,Static the shaft may not leak but turning it and any gear vibration may change your scenario it may leak ! Just sayin! Ya the fact that three machines in a week is suspicious !but at this point I can't connect any dots myself! Hope fully you fine some cracks in the heads but its a long shot! That said was the bore on number 6 injector pitted from rust and not sealing!? Also to add to the leaking shaft, temp change… Edited June 21, 2022 by Onyx610 Spelling 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500842 Share on other sites More sharing options...
Joey Mack Posted June 21, 2022 Author Share Posted June 21, 2022 the injector bore looked good.. I was able to clean it up with ease.. #6 was running 50 degrees cooler than the other 5 and they were within 10 degrees of each other. As far as the lift pump goes, I can understand youre concern. I did rotate the pump and push and pull on the gear and try to move it sideways, sprayed with windex and not 1 bubble... When I got the heads off. the #6 liner was really shiny, no cross hatching left.. I didnt go back today because of other road calls to go to. I hope I find some cracks too.. yes, its a long shot. The owner, told me an hour ago, to rebuild it.... he's done messing around.. I WILL replace the lift pump!!!.. Thank you for your input, its always welcomed.. jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-500845 Share on other sites More sharing options...
Joey Mack Posted June 23, 2022 Author Share Posted June 23, 2022 Well, no info on what caused the fuel in the oil. I inspected the cam while I was in there and the #1 exh. lobe has a chip in the lift.. So I am definately re-building this one too.. Be careful what you wish for.... I needed some work a couple weeks ago, and now I have 1 customer with 3 engines that need re-building.... An ASET-C, which I loaded pistons and liners into yesterday, waiting on the lifters.. An E-tech, and an E-7 V-Mac II.. I still have one of his ENDT 673's in my shop, and another 3 cyl. John Deere to build.. 🙄 Sorry I dont have an answer as to how the fuel got into the crankcase.. If I do find the reason, I will post it.. thanks guys, jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501041 Share on other sites More sharing options...
fjh Posted June 23, 2022 Share Posted June 23, 2022 (edited) Chances are you won't Find it ! As you said you WILL replace the lift pump! ain't worth taking the chance on your dime! You can't fix what you can't see! Magic wand time! 😁 Edited June 23, 2022 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501048 Share on other sites More sharing options...
Joey Mack Posted June 23, 2022 Author Share Posted June 23, 2022 Yep, My magic wand is on 'back order'.. No E.T.A. or notes on it... jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501057 Share on other sites More sharing options...
fjh Posted June 24, 2022 Share Posted June 24, 2022 (edited) you should check Amazon Free shipping when in stock! 😜 You may find that the crystal Ball assortment quantity's are low to there' s been huge shipping delay's I hear!🙃 Edited June 24, 2022 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501157 Share on other sites More sharing options...
Joey Mack Posted June 24, 2022 Author Share Posted June 24, 2022 I found a used one on E-Bay.. $1,000,000.00 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501159 Share on other sites More sharing options...
fjh Posted June 24, 2022 Share Posted June 24, 2022 Good score! Real bargain! Quote Link to comment https://www.bigmacktrucks.com/topic/69967-01-rd-688s-fuel-in-the-oil/#findComment-501163 Share on other sites More sharing options...
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