IGV Posted April 8, 2023 Share Posted April 8, 2023 Good morning everyone, I have a 2005 mack cv713 427I and recently I have been noticed that oil pressure at idle had dropped from 30-25 to 20, hot and barely reaches 40 at high speeds when it used to go up at around 50 60 psi, do you guys think is normal or what could be issue? I hope you all can help me, thanks in advance Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/ Share on other sites More sharing options...
Dirtymilkman Posted April 8, 2023 Share Posted April 8, 2023 Do an oil analysis. Check for fuel in oil too. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528787 Share on other sites More sharing options...
Joey Mack Posted April 8, 2023 Share Posted April 8, 2023 Yes too the oil analysis... when you pull the dipstick does the oil run off like water? You can do a halo test on a clean piece of card board to see if there is fuel in the oil. I have posted this test before.. It is not better than an oil analysis, but it will tell you right now if there is a fluid other than oil in the crank case.. Have the EUP's been replaced recently, or the fuel pressure regulator? fuel pressure should be between 50 + 80 PSI.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528788 Share on other sites More sharing options...
IGV Posted April 8, 2023 Author Share Posted April 8, 2023 No the oil does not run off like water, I'm been checking that also it looks ok, but what could cause the low oil pressure? Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528793 Share on other sites More sharing options...
Joey Mack Posted April 8, 2023 Share Posted April 8, 2023 hook a hand held pressure gauge to the oil filter stand and get a true reading.. The sensor may be failing. Dont open your wallet yet.. do a couple tests.. are you an 'engine guy'?? jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528794 Share on other sites More sharing options...
IGV Posted April 8, 2023 Author Share Posted April 8, 2023 Ok I will check the oil pressure with a gauge thanks,,, well I'm not an expert like you guys but I'm trying to learn because I'd like to be able to fix my truck my self because I like engines, jajaja, one more thing at cold start up the gauge needle stays down for a couple seconds and the very slowly starts to go up is that normal, thank you guys for your responses Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528795 Share on other sites More sharing options...
Joey Mack Posted April 8, 2023 Share Posted April 8, 2023 OK.. Thanks for being honest... There are a lot of us here that can help guide you.. The oil needle should rise quickly.. Just for kicks ,, remove the oil pressure sensor(s), should be on the right side of the oil filter stand behind the filter, and use some carb cleaner in a can and spray the end of the sensors till it is washed clean, re-install, and test it again.. Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528796 Share on other sites More sharing options...
IGV Posted April 8, 2023 Author Share Posted April 8, 2023 Ok thanks I'll check the sensor, oil pressure and get back to you guys for an update, you guys are awesome I appreciate you all Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528798 Share on other sites More sharing options...
Joey Mack Posted April 8, 2023 Share Posted April 8, 2023 🍻 remember,,,, keep your wallet closed for right now... 2 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528799 Share on other sites More sharing options...
IGV Posted April 8, 2023 Author Share Posted April 8, 2023 Ok I'll keep it closed and I hope it stays closed for much longer, jajaja thanks 👍 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528804 Share on other sites More sharing options...
mowerman Posted April 9, 2023 Share Posted April 9, 2023 I was just kind of curious, did it suddenly drop or was it gradual?… Bob Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528808 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Hey mowerman how are you, I'm guessing it di suddenly because one day I just noticed that it was 20 psi at idle hot and around 43 at high speed when it used to be around 30 at idle and 45 over 50 at full trottle, but since I noticed the oil pressure drop it's been dropping gradually, because now it's been dropping to 19 15 psi and barely go up to 40 full trottle. Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528850 Share on other sites More sharing options...
fjh Posted April 9, 2023 Share Posted April 9, 2023 11 minutes ago, IGV said: Hey mowerman how are you, I'm guessing it di suddenly because one day I just noticed that it was 20 psi at idle hot and around 43 at high speed when it used to be around 30 at idle and 45 over 50 at full trottle, but since I noticed the oil pressure drop it's been dropping gradually, because now it's been dropping to 19 15 psi and barely go up to 40 full trottle. AS Milkman has said ! Do the oil sample asap You may have fuel dilution smell the dipstick for fuel! Then check the sensors against a good gauge as Joe has mentioned ! your description points us in this direction in my mind! Common Failures on these is Fuel Pump And EUP Seals! Just sayin! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528851 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Ok will check thanks everyone will come with an update Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528855 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Hey guys I took a better look to the oil and it looks kinda thin, I know I need an oil sample but do you guys know how to check for fuel in oil ? Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528858 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528860 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 I did the halo test what you guys think Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528861 Share on other sites More sharing options...
Joey Mack Posted April 9, 2023 Share Posted April 9, 2023 picture #2 looks like fuel dilution to me.. I prefer card board because it slowly absorbs oil and quickly absorbs fuel or water.. but you did good.. what does the back side smell like? Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528862 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 It's smell like fuel to me Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528863 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Can you see the cardboard picture I sended one Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528864 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528865 Share on other sites More sharing options...
Joey Mack Posted April 9, 2023 Share Posted April 9, 2023 yes sir.. do you know the history on the EUP's? are they original, or have any been replaced right before this issue started? Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528866 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 Top sample is my brother's truck oil and bottom my truck's oil, we both the the oil change the same date Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528867 Share on other sites More sharing options...
IGV Posted April 9, 2023 Author Share Posted April 9, 2023 I think the eups are original haven't been changed recently, I just replaced one injector oring that was leaking Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528868 Share on other sites More sharing options...
Joey Mack Posted April 9, 2023 Share Posted April 9, 2023 I see the difference.. nice illustration.. you have something in the oil.. likely its fuel.. an oil analysis is in order, as was stated earlier.. Quote Link to comment https://www.bigmacktrucks.com/topic/72701-oil-pressure/#findComment-528869 Share on other sites More sharing options...
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