random multiple miss fire
#1
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I have a 2001 silverado with a 5.3l, i keep having SES light come on. It says that i have a random multiple missfire with a EGR code. i have new plugs and wires in it. THey are only 4 mounth old and have about 20,000miles on them. I have also replaced the EGR 3 time and i am still having this problem. Also i have valve chatter in cold weather anything under 40 degrees. I have noticed that the SES light turns on with the problem when i start it up to warm it up in the morning. Any one have any ideas or help? Thanks alot everyone.
#2
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what egr code is setting? any other dtc besides p0300?
The misfire only occurs at cold start-up? Ok underload and warm?
Do you have access to a scan tool? With it you can see misfire history and current misfires which will identify the cylinders that are misfiring. if they are all on one bank it will help narrow down the problem.
The misfire only occurs at cold start-up? Ok underload and warm?
Do you have access to a scan tool? With it you can see misfire history and current misfires which will identify the cylinders that are misfiring. if they are all on one bank it will help narrow down the problem.
#3
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not to sure my shop has been dealing with it. this is outside of my scope. when the truck sits over night and it is cold is when i find the ses light turns on. The EGR that i replaced the frist time only lasted 5,000 miles on it and the second on only lasted 2,500 miles. The missfire is been called a random multiple missfire. No one i have talked to and show the code to can't trace the missfire to a cylinder. could it have anything to dowith the valves chattering.
#4
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The chattering is more than likely piston slap. This is pretty common on the early 5.3L. Once it gets warmed up, the pistons expand and the excessive clearance is gone so the noise goes away. I had an 01 that I was fighting a misfire code like that. I finally did the egr valve, and evap purge solenoid and that cured it. If that doesn't, I would replace the intake gaskets. How many miles are on it?
#5
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Thanks, i will try purge solenoid next. i have 161866 on it now. had a friend tell me to try and replace the o2 sensors. Also one side of the engine is missfireing more on one side than the other.
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