Twitch Posted November 18, 2014 Share Posted November 18, 2014 I have a 1996 Ch with E7 350 and I am having an issue (hopefully not major) with a mysterious noise seemingly around the front of the engine. I cant really tell exactly where it is coming from but I have heard it in the past but has diminished shortly after idling and warming up. It seems to start on colder mornings and doesn't do it always but this morning it has sounded off and hasn't quit and increases with rpms. It sounds like someone is tapping on something with a hammer but not in a rhythm, although constant (sporadically). I am lost and don't know where to begin...As I have said had this problem in the colder temps last year but never persisted longer than 20-30 min warm up and didn't hear again the rest of the day. So now i have to decided to keep it parked unitl i can find a cure. Don't need to be buying an engine presently! Quote Link to comment Share on other sites More sharing options...
gearhead204 Posted November 18, 2014 Share Posted November 18, 2014 my e-9 did something similar last winter, it turned out to be a low spot in the air line that would freeze with condensate and overload the compressor that resulted in excessive gear noise. to check simply loosen the discharge line from the compressor and see if noise is reduced or vanishes. 1 Quote Link to comment Share on other sites More sharing options...
Twitch Posted November 18, 2014 Author Share Posted November 18, 2014 Thanks for the reply gearhead204. Although sounds like a possibility, I don't think that is my case, temps were only in the upper 30s to lower 40s here this morning so that would eliminate the freezing line. Oh how I wish it was something that simple! Seems as though all the problems I encounter are those that "have never been heard of before" or those that I seem to be the only one in this galaxy that has ever had that happen to! I don't know exactly what it is or where to begin to look, I've been trying to get up with my mechanic (about the only one I trust in my area) all this morning but have yet to get a call through. I went outside and started it again just to listen and its definitely coming from toward the front of the motor and almost sounds middle to lower half, in the region of the damper, so to speak. It's a tapping sound with no particular rhythm to it but taps about like something is pinging or hitting or something has come loose...This forum has been very helpul in the past with diagnosing alot of problems on my own, so I know the amount of "braintrust" up here someone can get me in the right directions. Quote Link to comment Share on other sites More sharing options...
masterwelder Posted November 23, 2014 Share Posted November 23, 2014 Fan belts loose, or squeaking in the pulleys... Quote Link to comment Share on other sites More sharing options...
Twitch Posted November 23, 2014 Author Share Posted November 23, 2014 Naw... belts new and tight. My guy is saying its an injector knocking... hope this is so. He seems to think just keep running it, not worth opening it up to fix yet. So I have ran it the last few days and the pinging goes away after a couple hours when everything warms up good. He said the fuel being cold and an injector slowly failing is the compilation of these problems (the noise). Does this make since to anyone? Have had a few trucks but have never come across this particular problem. Quote Link to comment Share on other sites More sharing options...
ranchhopper Posted November 23, 2014 Share Posted November 23, 2014 Check the harmonic balancer it may be ready to come apart I know in GM engines a bad harmonic balancer sounds like a rod or fuel knock. Quote Link to comment Share on other sites More sharing options...
gearhead204 Posted November 24, 2014 Share Posted November 24, 2014 does that e-7 have external injection lines? ( sorry its been to long for me looking at the different eng. configurations) if so when you fire it up simply loosen each line one by one( one at a time) and listen for the knock to go away or diminish.a few years ago i got a rebuilt injection pump and installed it on a machine i had not taken apart and had a knock. i could loosen a line and all was well tighten it back up and knock knock knock so i swapped injectors and the problem stayed in the same hole so i pulled the eng. expecting a failed brg. but all good, magna fluxed all components thinking some thing was cracked. but no, had all things checked for balance and were good. reassembled and ran damn knock was back......@#$%!&$# any how went back to the fuel system and removed one injector at a time and caught the fuel spray in a c.c. marked tube and found one cyl. was over fueling, called the rebuilder and found out he never screws up, after a 30 min. call and a threat to drive to yakama and re arrange his pump stand, he agreed to re check his work! 2 days later i got a very apologetic phone call that one barrel had slipped and was indeed over fueling. sorry about the long story but a injector can cause a knock ! some times its the injector some times its the pump. Quote Link to comment Share on other sites More sharing options...
Twitch Posted November 26, 2014 Author Share Posted November 26, 2014 ok well thanks for the info. Sounds as if the injector problem may not be so far fetched after all. I initially thought last year when i heard that noise that it was the damper but I dont think there is anything in it to cause that kinda of fuss. However that being said everyone that sells dampers says change every 500k but every mechanic I have ever asked that question to says never heard of that 500k interval on a damper... GO FIGURE! It's nice to know I have company here in the "scratchin' my head club" when it comes to these dilemmas. I appreciate all the input. Hopefully it will keep holding on for a while, seems like here lately it's one thing after the next... I always just relate it to - "It's F@#$&n' Truckin' " The old girl runs great otherwise, avg. mpg 5.5 - 6, gets me there and back but is painfully underpowered for what I do. I haul lots of grain, lime, rock and always grossing over 80k and looking at the size of that motor I guess i'm lucky it does all it does. It's like they say "run what you brung"! Quote Link to comment Share on other sites More sharing options...
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