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Can't stop the pinging (AND THE FIX)

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Eric M., Aug 16, 2003.

  1. Eric M.

    Eric M. 1/2 ton status

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    Can\'t stop the pinging (AND THE FIX)

    I've got an 87 V3500, 454, Turbo 400. It is pinging under acceleration. No codes, I plugged in my Scan tool and the computer and all sensors are operating within their parameters. I put in a tank of Supreme, no change. The cap, rotor and plugs are new. I've checked timing (disconnected the "brown" wire first).

    Any ideas??


    Thanks,

    Eric M.



    THE FIX 9/22/03

    On 454s, the harmonic balancer has a band of rubber between the inner portion and the outer ring with the timing mark. As the balancer gets older, that rubber deteriorates, allowing the outer ring to move from it's original location, thus, showing the incorrect timing when using a timing light. I picked up a new balancer from LMC, bolted it up and found that the timing was 12 degrees off. Now it runs fine while set at the factory 4 degrees BTDC and no pinging.

    I wanted to post for others doing searches for pinging 454s.

    Who'd a guessed that was the problem /forums/images/graemlins/confused.gif


    Eric M.
     
  2. Foy

    Foy Registered Member

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    Re: Can\'t stop the pinging HELP!

    I'd try a really intense decarboning with Sea Foam or something like it. Maybe two treatments. I think the idea is that carbon builds up on the piston and in the combustion chamber and can cause detonation. If that doesn't do it, put a real temp gauge on it and see if you're running hot--the standard gauge may not be reading correctly. My dad's old '84 Sub pinged like crazy until he installed a 4 tube radiator, then never again. The standard gauge showed it running about two needle's widths above normal, but it must have been running too hot.

    The Sea Foam trick is easy and pretty cheap--about $4 a pint here, and that's enough for 2 treatments. Just follow the instructions on the can.
     
  3. HarryH3

    HarryH3 1 ton status Author

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    Re: Can\'t stop the pinging HELP!

    Since the tranny was just out... Check the vacuum line that goes from the modulator, on the right side of the tranny, up to the intake manifold and make sure it's connected properly. Then check the vacuum lines that operate the EGR valve. One may have been disconnected or cracked when they were removing the tranny. An inoperative EGR valve can cause massive pinging.
     
  4. Confedneck

    Confedneck 3/4 ton status

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    Re: Can\'t stop the pinging HELP!

    try using sea foam deep creep down the throttle body a lot of it..or try some atf..
     
  5. Stoopalini

    Stoopalini 1/2 ton status

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    Re: Can\'t stop the pinging HELP!

    When it pings, does your scan tool show a timing retard? If not, your knock sensor/ESC could be bad/disconnected.

    Thomas.
     
  6. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Can\'t stop the pinging HELP!

    Since nobody payed attention to what you have, TBI, and tranny swap then started happening lets start with the simple stuff before we start dumping cocktails down it's throat and ruin the O2 sensor.

    Your truck has a knock sensor. The tranny guy screwed it up some how. Proably unplugged or the wire got pinched between the bellhousing when he put the tranny back. Should be on the passenger side of the block up by the starter screwed in to the drain port just above the oil pan. Proebely knocked the wire off when he dropped the starter. Check the O2 sensor as well he had to drop the Y pipe and may have goofed things up there as well. Its on the driverside manifold by the shift linkage.
     
  7. Eric M.

    Eric M. 1/2 ton status

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    Re: Can\'t stop the pinging HELP!

    The 7.4 (454) and the 2.5 (2.6 or something like that) in 87 did not have knock sensors. I'm not sure how they read knock, maybe they don't. The Scan tool reads a continuous knock, from 1 to 255 then resets. I tried the scan on my other 87 454 which is running fine and it reards the same thing for knock. I think since the 454 doesn't have a knock sensor, it just keeps cycling through. Any thoughts on this?

    The Scan tool says everything is fine and operating. I did the ATF in the intake (my neighbors thank you for the blinding smoke storm!). No change. I installed new spark plug wires and reinstalled the snorkle from the air cleaner to the grill (cold air to intake) and one or both helped a bit ... although it was cold and foggy when I test drove it so that may have helped a bit too. I have now retarded the timing to 0 degrees. That helped some too, but it's still there, and that is running on Supreme (92).

    Now what??


    Eric M.
     
  8. HarryH3

    HarryH3 1 ton status Author

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    Re: Can\'t stop the pinging HELP!

    Didja check for proper EGR valve operation yet?
     
  9. Eric M.

    Eric M. 1/2 ton status

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    Re: Can\'t stop the pinging HELP!

    yes, I checked for proper EGR operation. Used the vac. pump. It opened and held vacuum.

    Eric M.
     
  10. HarryH3

    HarryH3 1 ton status Author

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    Re: Can\'t stop the pinging HELP!

    But did you check to see if it's actually getting vacuum from the engine? If the tranny guys left a vacuum line loose, then you could have just enough of a leak to prevent the EGR from working. Lack of EGR can cause some serious pinging. I suspect this only because you said it started right after the tranny was repaired.
     
  11. jmd

    jmd Registered Member

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    Re: Can\'t stop the pinging HELP!

    [ QUOTE ]

    pinging under exceleration.

    I did just have the transmission and torque converter rebuilt ... it didn't ping before that.

    [/ QUOTE ]

    Tell them to put the right tq. converter in. Too tight a converter will cause problems like that; I just put a cheap-o tq. converter in my car in front of a fresh 700-R4 and it pings because it doesn't stall as high as the 200-4R did and I KNOW I didn't loosen any wiring, vac. lines or otherwise 'cause I'm the only person who touched the car during the swap.

    -Matthew in Abq. /forums/images/graemlins/truck.gif
     
  12. Eric M.

    Eric M. 1/2 ton status

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    Re: Can\'t stop the pinging (AND THE FIX)

    See top post for fix.

    Eric M.
     
  13. 77Jimmy

    77Jimmy 1/2 ton status

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    Re: Can\'t stop the pinging (AND THE FIX)

    Thanks for posting up the fixes. /forums/images/graemlins/thumb.gif I think it's great when people do that...brings closure to a thread and is there for future reference. /forums/images/graemlins/thumb.gif Thanks! /forums/images/graemlins/thumb.gif
     
  14. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Can\'t stop the pinging (AND THE FIX)

    Thanks for the update. Not unheard of for that to happen on any harmonic ballancer of that style. I'll have to keep an eye on mine. So far I have not heard any ping so hoepfully mine is still true.
     
  15. monte0172

    monte0172 1/2 ton status

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    Re: Can\'t stop the pinging (AND THE FIX)

    A real easy way to check this is to bring the #1 cylinder up to TDC on the compression stroke and check where you timing mark on you balancer is opposed to the mark on the cover. Should be no more that a degree or two off from 0 given the wear and tear of the timing chain.
     
  16. monte0172

    monte0172 1/2 ton status

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    Re: Can\'t stop the pinging (AND THE FIX)

    Nevermind about the timing chain part wasnt thinking should be directly on 0 no matter what.
     
  17. justhorsinaround

    justhorsinaround 3/4 ton status

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    Re: Can\'t stop the pinging (AND THE FIX)

    By the way, if you don't have the cash to replace that style of harmonic balancer and you adjust the timing to compensate for the slippage, be very aware. That means the rubber is no longer vulcanized to the metal and the two pieces are slowly coming apart. Eventually, they will let go and cause one hell of a bit of damage. Just kind of a FYI. Good luck to y'all.

    Allan
     

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