Jump to content

dumbfounded on cylinder #6 misfire

mhicks
 Share

Recommended Posts

mhicks New Member

mhicks

Posted
Posted

Hello everyone. I have a 2013 Silverado 2wd with a 4.3 v6 and it's coming up with a cylinder #6 misfire code and dumping enough white smoke to make a pest control company jealous.
I have replaced the plugs and wires (wasn't smoking then) and it ran great for all of about 36hrs before coming back with the misfire. Still no smoke signals at the time, so I replaced the Ignition coil and all seemed well for about another 24hrs before it started releasing it's mosquito repellant and misfiring again.  I have replaced plugs, wires, ignition coil and the complete spider injection system and it still plagues me with smoke and a miss. What am I still missing to check? I have ran 3 different compression tests and nothing has showed below 142psi on any cylinder. Could it be an issue with the PCM? I've never ran into this issue before and any/all information is appreciated! I don't have the diagnostic equipment I would like to have, but I'm trying to save myself from paying for a potential mis-diagnosis or any more "swing and misses". Thank you all and have a great day!

asilverblazer Senior Enthusiast

asilverblazer

Posted
Posted

New parts doesn't guarantee good parts. 

 

Try swapping one component at a time from the bad cylinder to a good cylinder. Plug, wire, coil, etc... 

 

Have you checked compression in its current state? Might have ran too lean too long and burned a valve...

 

If it is indeed ONLY cylinder 6, and the above 'external' cylinder specific items aren't the culprit, then its an internal engine issue... 

 

For the sake f being thorough, I'd through a vacuum gauge on it and spark tester.

  • Like 1
mhicks New Member

mhicks

Posted
  • Author
Posted
1 hour ago, asilverblazer said:

New parts doesn't guarantee good parts. 

 

Try swapping one component at a time from the bad cylinder to a good cylinder. Plug, wire, coil, etc... 

 

Have you checked compression in its current state? Might have ran too lean too long and burned a valve...

 

If it is indeed ONLY cylinder 6, and the above 'external' cylinder specific items aren't the culprit, then its an internal engine issue... 

 

For the sake f being thorough, I'd through a vacuum gauge on it and spark tester.

At one point, I sold auto parts and can sadly confirm this statement to be true. 

I have done the swapping around on the parts prior (after checking the tip of the spark plug) to the tune-up with no indications of the misfire moving cylinders. It does have the newer one coil pack design vs the individual packs. It ran for all of 2 minutes after installing the new spider injection system yesterday before the smoke came back. I did run the compression test again afterwards and it had only dropped to 140. I have yet to check it with a vacuum gauge, but it does have good spark.

newdude Senior Enthusiast

newdude

Posted
Posted (edited)
2 hours ago, mhicks said:

Hello everyone. I have a 2013 Silverado 2wd with a 4.3 v6 and it's coming up with a cylinder #6 misfire code and dumping enough white smoke to make a pest control company jealous.
I have replaced the plugs and wires (wasn't smoking then) and it ran great for all of about 36hrs before coming back with the misfire. Still no smoke signals at the time, so I replaced the Ignition coil and all seemed well for about another 24hrs before it started releasing it's mosquito repellant and misfiring again.  I have replaced plugs, wires, ignition coil and the complete spider injection system and it still plagues me with smoke and a miss. What am I still missing to check? I have ran 3 different compression tests and nothing has showed below 142psi on any cylinder. Could it be an issue with the PCM? I've never ran into this issue before and any/all information is appreciated! I don't have the diagnostic equipment I would like to have, but I'm trying to save myself from paying for a potential mis-diagnosis or any more "swing and misses". Thank you all and have a great day!

 

 

White smoke strong enough to make a pest company jealous?  

 

Heavy white smoke sure isn't a sign of a bad coil, spark plug or injector, and I'm sorry to hear you dumped money on plugs, wires, coil AND new fuel injection system.  That is an almost sure sign of coolant getting into that cylinder.  

 

Its either a bad head gasket or the intake manifold lower gaskets are leaking.  The intakes on these old 4.3s are "wet" intakes, coolant does flow through them unlike the newer engines which are all "dry" intakes.  

 

A block combustion gas detector can be used to sniff out combustion gases in the coolant which could indicate bad head gasket.  A cylinder leakdown test is something worth doing as well.  

Edited by newdude
  • Like 1
dna9656 Enthusiast

dna9656

Posted
Posted

After reading what the guys (that know more than I) say I'd replace the head and intake gaskets.... Now that means taking the intake and the heads to the man (machinst)  and getting the heads and intake made true, square, tangent, and congruent; IOW square and true! then put the ucker back together In Accordance With (IAW) Chevrolet.

asilverblazer Senior Enthusiast

asilverblazer

Posted
Posted

I must've missed the WHITE smoke part... Not real positive, but a good compression test suggests coolant entering the air intake tract between the valves and throttle body. An internal leak/crack in the manifold, or, if you're lucky an intake manifold gasket. 

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

You could always try a stop leak product. I bought a used car once that I did a coolant flush. Shortly after it wouldn’t turn over. After pulling the plugs and pumping the water out, I added bars leak fixing the problem. My 02 avalanche has the famous head crack problem. It leaked into the oil after shutting off. The water stayed at the bottom of the pan never mixing with the oil. Bars leak fixed that going on its second year. I’ve had three vehicles so far that had leaks that bar’s leak have fixed. There’s even stronger products that fix even the worst of leaks. If nothing else it would point to the problem by eliminating the problem. Then you can make your decision. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • newdude
      Me too……..

      By newdude · Posted

      The engine was done as part of the 6.2 recall?   You'd have to see if your VIN also has the 6.2 engine special coverage on it.  Coverage number is N252494003.  If you have this, your engine is covered under this and NOT the GM replacement part engine warranty which is 3yr/100k from the date of install.  The 3yr/100k mi warranty is in effect for non warranty purchases.     This is not any different if it was replaced under warranty without a recall or special coverage.  So if you had a 5.3 and it popped at 3 years in at 50,000mi during the 5yr/60k powertrain, the replacement engine would not get the 3yr/100k, and instead gets the remainder of the 5yr/60k as coverage.     So N252494003 gives 10 years or 150,000mi of coverage, which ever comes first, starting at the vehicle in service date.  So if your in service date is 01/01/2022, N252494003 gives you special coverage of the engine until 01/01/2032 or 150,000mi, whichever comes first.  So if your start date was 01/01/2022, you'd have left 5 years and 4 months (lets round to august 1st), or 62,000mi left of coverage.   So you need to know your in service date to know how much coverage is left.  
    • CamGTP
      Injector update

      By CamGTP · Posted

      Okiee dokie there bud, way to take things to the extreme.   I guess you missed the whole point and take things way to serious. I installed different EV6 style injectors that just so happen to be larger in my car running the same LQ4 engine and with a better spray pattern than the stock style injectors and I noticed no difference in the idle quality. Kinda was my round about way of saying that even if you put the same size but better style injectors in your truck, you will likely see the same thing.    I'm sure you're great to have conversations with in person if that's how you act through a keyboard. One little things sets you off and now I guess my dick is all up in your face.
    • richard wysong
      Injector update

      By richard wysong · Posted

      WoW
    • taze
      Me too……..

      By taze · Posted

      I can't believe that could possibly be the case. It should be 36mo/100k miles from installation. Then again, it also seems like since a dealership installed it, it'd all be in the system and you wouldn't need to worry about registering, either. Shows you what I know. 😄 Hope this one outlives the warranty!
    • asilverblazer
      The Peckish Synapse

      By asilverblazer · Posted

      I haven't seen inventory recovery from COVID.    In the few random times I 'build my own' truck or SUV, no one has the exact one I want.   GM has been working to lower incentives too for a long time.    A $500 incentive isn't getting me off the couch to go truck shopping.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...