Straydog954 Posted May 13 Share Posted May 13 Was looking at a low mileage e7 full mechanical. Started very easily and idled nice. Oil pressure was about 32 at idle cold and it went up to 80 at full throttle after warmed up. I noticed when the oil pressure hit appx 60 that the engine started to studder and shake a bit then smoothed back out when it hit 70 lbs and was smooth all the way to 80. Any ideas what would cause this ? An injector maybe? Engine has a dynatard on it and it was not working not sure why. Engine had very little blow by out of the top of valve cover and nothing out of draft tube Any ideas on the miss ? Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/ Share on other sites More sharing options...
Joey Mack Posted May 14 Share Posted May 14 oil leak passed an o-ring in the engine brake heads celenoid.. with the higher oil pressure. FJH, Mech?? what say you? Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551650 Share on other sites More sharing options...
mechohaulic Posted May 14 Share Posted May 14 another perspective is :: ok at 32lbs .. rocky at 60 ; better 70+. oil pressure changes with R P M's =correct ? out of balance some where?? 32lbs ==idle :60lbs =RPM's ???. 70lbs + == high RPM's . dynatard o-ring leak makes a pis- poor engine brake worse , if that's possible . shouldn't create a shake/ shutter ?? this is fun ,questioning the teacher ,😅 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551652 Share on other sites More sharing options...
mechohaulic Posted May 14 Share Posted May 14 foul injector shouldn't clear itself out higher RPM's . skips a skip. dynatard not working at all?? possible totally different issue Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551653 Share on other sites More sharing options...
Joey Mack Posted May 14 Share Posted May 14 Mech,, your the teacher... I'm just trying to be an astute student of your knowledge.. My goal is to impress you.. just sayin'.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551655 Share on other sites More sharing options...
Joey Mack Posted May 14 Share Posted May 14 Well, my go to on these issues is to check the valve adjustment. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551656 Share on other sites More sharing options...
JoeH Posted May 14 Share Posted May 14 Was it a stutter or a flutter? Governor springs can cause the engine to flutter at midrange RPMs. My front end loader has been doing it a lot lately, revved up coasting at minimal load the RPMs flutter. My 95 e7-350 (fully mechanical) will do a similar flutter in that 1300 + or - range coasting minimal load every so often. Truck runs great otherwise. Maybe the truck you looked at is doing the same thing mine does or maybe it could use a fuel filter. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551659 Share on other sites More sharing options...
mechohaulic Posted May 14 Share Posted May 14 so would I not be too far off going another avenue to possible RPM's may join the issue ?? once again not being there to see/hear issue adds to challenge. forum is reading of shake/shutter at certain oil pressures, not knowing units "behavior" under operating conditions== good power on road test etc. parked with fuel pedal movement only. ? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551660 Share on other sites More sharing options...
Joey Mack Posted May 14 Share Posted May 14 bad engine mounts??? Nite Nite Birthday Boy !! luv u Bud.. Jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551662 Share on other sites More sharing options...
Straydog954 Posted May 14 Author Share Posted May 14 Truck has been sitting for a couple yrs. Oil filter was last changed in 2018 I see so I can only imagine fuel filters are old. Has really not been used much in last few yrs. I took a video clip on my cell phone maybe my kid can figure out how to down load it Engine studders or whatever you call it and shakes and then smooths out at higher rpms Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551665 Share on other sites More sharing options...
mechohaulic Posted May 14 Share Posted May 14 thanks for update/ more info. oil has 5+ years on it, fuel filters the same (?) on a mechanical = could be big part of issue. might be simple fix. truck meets your approval based on condition / price / mileage ; go for it.. any answer why it was parked? non working engine brake may be another simple fix = relay: broken wire and so on. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551667 Share on other sites More sharing options...
Straydog954 Posted May 14 Author Share Posted May 14 FullSizeRender.mov Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551668 Share on other sites More sharing options...
Straydog954 Posted May 14 Author Share Posted May 14 FullSizeRender.mov Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551670 Share on other sites More sharing options...
JoeH Posted May 14 Share Posted May 14 That sounds like a bit more of a miss than my truck's flutter. Almost sounds like a knock? But I will admit to not having hardly any experience with engine knocks/misses, and my phone has crappy speaker audio. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551673 Share on other sites More sharing options...
fjh Posted May 14 Share Posted May 14 So just a comment on this ! If its a ROBERT bosch manual pump (likely is) identify which cylinder likely number 1 The delivery valve washers are made of copper these have been known to crack and leak by internally ( specially on number one) and cause a miss most noticeable At Idle! Crack fuel lines at the pump till you find one that doesn't change the sound of the engine that will be your culprit ! just something to look for! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551682 Share on other sites More sharing options...
Straydog954 Posted May 16 Author Share Posted May 16 On 5/14/2024 at 8:31 AM, fjh said: So just a comment on this ! If its a ROBERT bosch manual pump (likely is) identify which cylinder likely number 1 The delivery valve washers are made of copper these have been known to crack and leak by internally ( specially on number one) and cause a miss most noticeable At Idle! Crack fuel lines at the pump till you find one that doesn't change the sound of the engine that will be your culprit ! just something to look for! This is most likely a pump issue you think? Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551801 Share on other sites More sharing options...
fjh Posted May 16 Share Posted May 16 Not always But a possibility ! is the truck drivable ? do you have a local fuel shop in your area? it requires a special socket to remove the delivery valve! Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551803 Share on other sites More sharing options...
Joey Mack Posted May 16 Share Posted May 16 bent pushrod?? run the valves.. was the injection pump removed recently? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551804 Share on other sites More sharing options...
fjh Posted May 16 Share Posted May 16 2 minutes ago, Joey Mack said: bent pushrod?? run the valves.. was the injection pump removed recently? 👍 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551805 Share on other sites More sharing options...
Joey Mack Posted May 16 Share Posted May 16 I have heard that sound many times, and im not gonna say its not fuel delivery, but I have a habit of running the valves. what if a pushrod was off to the side and got put back in the lifter without inspecting it first? just a few things I have found in the past.. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551806 Share on other sites More sharing options...
fjh Posted May 16 Share Posted May 16 1 minute ago, Joey Mack said: I have heard that sound many times, and im not gonna say its not fuel delivery, but I have a habit of running the valves. what if a pushrod was off to the side and got put back in the lifter without inspecting it first? just a few things I have found in the past.. Yup I agree Joey start with the cheap and easy ! It was just an honorable mention at the start there! That said the miss for a push tube would likley be accompanied by a ticking noise the stumble maybe a clue as well! crack some fuel lines and identify which cylinder it is and start by checking the valve set! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551807 Share on other sites More sharing options...
Popular Post Joey Mack Posted May 16 Popular Post Share Posted May 16 yep,, cracking the fuel lines should narrow it down.. this one of those times I wish I/We were there to try and fix it.. I'm out sick today, so I will be here bugging people today.. 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551808 Share on other sites More sharing options...
fjh Posted May 16 Share Posted May 16 1 minute ago, Joey Mack said: yep,, cracking the fuel lines should narrow it down.. this one of those times I wish I/We were there to try and fix it.. I'm out sick today, so I will be here bugging people today.. Get well soon! Bro! Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551809 Share on other sites More sharing options...
Joey Mack Posted May 16 Share Posted May 16 im ok, my left knee is in really bad shape, I had a shot in it yesterday, so today im resting it.. Some of the worst pain ever.. thanks Bud.. Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551810 Share on other sites More sharing options...
fjh Posted May 16 Share Posted May 16 I just had my back done two weeks ago! Doing some what better how ever there no replacement for new parts!🙄 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74157-engine-miss/#findComment-551832 Share on other sites More sharing options...
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