Knocking sound from a 7.3 idi with a turbo

Discussion in '6.9L IH & 7.3L IDI Diesels' started by 1978FrankenFord, Oct 10, 2018.

  1. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Ive got a 94 with a 91 7.3 idi that i put the factory turbo on from the 94 idit. Its making sort of a knocking and a pssshhh noise too and im not sure what it would be. Runs great and starts amazing! Heres a link to the video i took- any help is appreciated! Thanks!
     
  2. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

    Posts:
    4,834
    Likes Received:
    2,734
    Joined:
    Jul 27, 2015
    Location:
    Bulverde, Texas
    It’s probably the red paint on the valve covers affecting the hydraulic lifters.

    All kidding aside, it’s probably a fuel knock. Crack open one injector line at time and see if the noise changes
     
    The_Josh_Bear likes this.
  3. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Haha i was trying to match the paint on my truck when i had the motor out a long time ago as you can see the paint kind of wore off. I did crack each injector and the noise would kind of disappear but on each one i cracked it would run crappy and ive heard that if you have a bad injector its supposed to sound the same if the bad injector is cracked but i could be wrong. I also took a piece of rubber hose and did the noise check on each line and the knock sounds really bad at the injector on the drivers side closest to the radiator
     
  4. Mathieu Gilbert

    Mathieu Gilbert Registered User

    Posts:
    4
    Likes Received:
    0
    Joined:
    Oct 11, 2018
    Location:
    Canada
    Did you find the problem, because the same thing is happening to me and I am going crazy. Mine is a bit more quiet without engaging the transmission, but when I drive it sounds exactly the same.
     
  5. Kevo1288

    Kevo1288 Full Access Member

    Age:
    29
    Posts:
    98
    Likes Received:
    39
    Joined:
    Feb 19, 2015
    Location:
    North Grosvenordale
    Stuck lifter maybe?
     
  6. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    I havent found out what the problem is yet. Im not sure how old the injectors are but im hoping its not a stuck lifter. I guess i could pop the valve covers off and look to make sure everything is good. I might try some new injectors, but i think first ill dump some atf and diesel deep clean in the tank and see if i can clean things up
     
  7. Thewespaul

    Thewespaul Supporting Vendor Supporting Member

    Posts:
    4,834
    Likes Received:
    2,734
    Joined:
    Jul 27, 2015
    Location:
    Bulverde, Texas
    It’s a fuel knock. Swap the injector that seems noisy to the other side of the engine and see if the noise follows it, I recommend this for both y’all a cases
     
  8. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Thanks for the input and i hope your right that its fuel knock! I threw some diesel deep clean and atf in to see if maybe i could clean out the bad injector but if worse comes to worse ill get new injectors
     
  9. grizzlyjosh

    grizzlyjosh Registered User

    Posts:
    17
    Likes Received:
    0
    Joined:
    Jan 31, 2015
    Location:
    Asheville, NC
    I just finished putting my truck back together after diagnosing a similar knock. My knock was pretty light and kind of sporadic at idle but would get stronger and more regular with throttle. I tried a bunch of things to figure out the problem but finally decided that it must be exhaust valve trouble after taking my turbo off. The 'knock' sound turned into more of a 'chuff' sound and the exhaust was coming out in puffs rather than a steady stream. I found a video that someone had posted somewhere of their truck 'chuffing' from exhaust valves sticking and it was just like mine. Sure enough, once I had the heads off and the machine shop looked at them, they found that all of the exhaust valves in one head were sticking open.
    I hope it turns out to be fuel problems for your sake but if it isn't, do a little reading about 'chuffing' and see if it rings a bell.
     
  10. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Im hoping it is just a fuel knock too. Thats kind of a bumber about your exhaust valves sticking open. The diesel deep clean and atf fluid didn't work to clean it so sometime when i get time ill swap in some newer good injectors and see if that fixes my problem
     
  11. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    1,961
    Likes Received:
    797
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    In the mean time, you could pull your valve covers and look at the bottom of them. If there's anything that looks "sooty", then you have valve guide issues. This could be on the bottoms of your valve covers or on the exhaust valve springs.
     
    Kevo1288 likes this.
  12. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Would it just be like a black soot kind of on the bottom of the valve covers? This would tell me if i have bad valve guides or exhaust valves? Ill probably check this out too while im jacking with the injector
     
  13. Kevo1288

    Kevo1288 Full Access Member

    Age:
    29
    Posts:
    98
    Likes Received:
    39
    Joined:
    Feb 19, 2015
    Location:
    North Grosvenordale
    No look around the valve stems where the valve goes through the heads.
     
  14. 1978FrankenFord

    1978FrankenFord Registered User

    Posts:
    34
    Likes Received:
    1
    Joined:
    Mar 20, 2018
    Location:
    Nebraska
    Alright ill take a look at that whenever i get time to look at it
     
  15. IDIBRONCO

    IDIBRONCO IDIBRONCO

    Posts:
    1,961
    Likes Received:
    797
    Joined:
    Feb 5, 2010
    Location:
    edmond, ks
    If the guides are bad enough, then the soot will be blown on the underneath of the valve covers too. With the compression that these engines have, it won't take much to blow the soot that far.
     

Share This Page