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Thread: Valves Rattle

  1. #1

    Default Valves Rattle

    Hello,
    I have a 2004 Z71 with a 5.3L. I have noticed when I go over half throttle to full the valves will rattle. This happens usually until 3rd then stops. Depending on where I get fuel it could be worse. I try to keep 93 in it but even with that still happens. There is 200k miles on it. I do have a superchip programmer and this seems to be worse in performance tune. Now when the truck is in park or neutral doesn't seem to happen when I rev it up. What the heck! Is this a serious problem? What can I do other than replace the valves?

  2. #2
    Legend

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    Default

    Quote Originally Posted by Diesel Fuel View Post
    Hello,
    I have a 2004 Z71 with a 5.3L. I have noticed when I go over half throttle to full the valves will rattle. This happens usually until 3rd then stops. Depending on where I get fuel it could be worse. I try to keep 93 in it but even with that still happens. There is 200k miles on it. I do have a superchip programmer and this seems to be worse in performance tune. Now when the truck is in park or neutral doesn't seem to happen when I rev it up. What the heck! Is this a serious problem? What can I do other than replace the valves?
    sounds like the timing is off. you may need to have the crank re learn procedure done. dealership charges about 100 USD for this. I would also check for proper fuel pressures 53PSI min engine on.

    the sound is not because of the valves but pinging due to pre ignition from what you describe is the sound and operating conditions..

  3. #3

    Default

    Mine did the same thing as the original posted described. mine only happened at WOT, like when merging into traffic on the highway. I had a friend do the crank relearn the sound has decreased significantly and my mpg has gone up.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors, http://www.gmtruckclub.com/forum/sho...5-GMC-Yukon-XL
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  4. #4

    Default

    So the timing chain doesn't need to be replaced? I was told since it only happens under a load and not once the motor plains out. Keep in mind when I get to 45-50 an get on it I done get any rattling valves.

    - - - Updated - - -

    BTW fuel pressure is 62

  5. #5
    Legend

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    Sep 2010
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    Default

    Quote Originally Posted by Diesel Fuel View Post
    So the timing chain doesn't need to be replaced? I was told since it only happens under a load and not once the motor plains out. Keep in mind when I get to 45-50 an get on it I done get any rattling valves.

    - - - Updated - - -

    BTW fuel pressure is 62
    never heard of timing chain issues with these engines ..what type of repair shop told you that ? was this a GM dealership ?

    with key on engine off 62 psi is the high end. running this will drop to about 55-58 psi..

    the re-learn is the timing chain ,pcm electronic signal connection. as things wear out the re-learn may need be done to properly calibrate these two components. this is not something that almost never happens but is quite common..

    timing chains being worn out is very very rare..engines with over 200,000 miles I have never heard of this timing chain.

    they must be looking for work better go elsewhere !

  6. #6

    Default

    Quote Originally Posted by j cat View Post
    never heard of timing chain issues with these engines ..what type of repair shop told you that ? was this a GM dealership ?

    with key on engine off 62 psi is the high end. running this will drop to about 55-58 psi..

    the re-learn is the timing chain ,pcm electronic signal connection. as things wear out the re-learn may need be done to properly calibrate these two components. this is not something that almost never happens but is quite common..

    timing chains being worn out is very very rare..engines with over 200,000 miles I have never heard of this timing chain.

    they must be looking for work better go elsewhere !
    I agree with J-cat. The chain may stretch over time but I have not heard of them going bad. I tested my truck last night. I had the relearn done about 1000 miles ago. I do not have the noise at all anymore. It took a few hundred miles for the pcm to readjust everything after the relearn. But, now the noise has completely stopped.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors, http://www.gmtruckclub.com/forum/sho...5-GMC-Yukon-XL
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  7. #7

    Default

    Quote Originally Posted by Pikey View Post
    I agree with J-cat. The chain may stretch over time but I have not heard of them going bad. I tested my truck last night. I had the relearn done about 1000 miles ago. I do not have the noise at all anymore. It took a few hundred miles for the pcm to readjust everything after the relearn. But, now the noise has completely stopped.
    Thanks Guys! I called the dealership today and scheduled to go in for the relearn. They said this would take an hr or so and the price is $93. I'll keep you posted.

  8. #8

    Default

    ouch! It literally takes less than 5 minutes. They input your vehicle info into the scan tool. They then start the truck and redline it for a second. When they did mine the guy just put the gas pedal to the floor for a split second. A "blip" of the pedal and the relearn was done. It sucks that the dealers code this as a computer diagnosis and charge a minimum of an hour. Lucky, my friend did it for me for a case of beer and a pack of smokes.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors, http://www.gmtruckclub.com/forum/sho...5-GMC-Yukon-XL
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  9. #9

    Default

    Quote Originally Posted by Pikey View Post
    ouch! It literally takes less than 5 minutes. They input your vehicle info into the scan tool. They then start the truck and redline it for a second. When they did mine the guy just put the gas pedal to the floor for a split second. A "blip" of the pedal and the relearn was done. It sucks that the dealers code this as a computer diagnosis and charge a minimum of an hour. Lucky, my friend did it for me for a case of beer and a pack of smokes.
    Here it is Guys-from the dealership. Carbon buildup. I need to run 4-5 tanks with GM Fuel System Cleaner. I also read a couple of post on Sea foaming the engine. I've done the sea foam before just in the brake booster line though. Think I'll try it to remove more. They also recommended only 93 Octane from Chevron and I had been running 89. There were other gas stations I could use 87 and be ok.

  10. #10
    Legend

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    Sep 2010
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    Default

    since you have a PCM tuner on this vehicle most likely this caused the carbon issue.

    carbon reduces the size of the combustion chamber then the pinging.

    the tune must be screwed up..

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