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Entire bank, intermitently miss firing

fatluke

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fatluke Enthusiast

fatluke

Posted
Posted

Hey,

 

The truck is an 02 Silverado, 5.3 L 4x4.

 

It start to run a little rough so I had it into a shop and on a scanner. It was showing missfires on cylinders 1,3,5,7.

 

I then changed all the plugs on that side, but the same thing. I also tried switching the wires from the other side. But again the same thing.

 

I prefer to fix problems by myself, if it is possible, So here are my questions.

 

THe mechanic that scanned it, said it could be the coil pack. Now from what I can see, each cylinder has it's own coil. So would it be all 4 of these, or is there something else that drives the entire bank of coil banks.

 

Any help or suggestions would be greatly appreciated.

fatluke Enthusiast

fatluke

Posted
  • Author
Posted
If your planning on digging that far into the problem you better get a Factory Service Manual for Heims.

http://www.helminc.com/helm/homepage.asp?r=

 

 

I'm not looking too far into it.. If someone had a simple solution of swapping some parts, I would be able to do it... If I don't hear anything by Sunday evening it is going to the shop for someone else to fix.. I am a young person with major debts and I like to keep things as cheap as possible. So if I can do it myself, I will, otherwise I will have to pay that nasty labour charge to someone else.

rgdepew Enthusiast

rgdepew

Posted
Posted

I had the same thing on my 2003 about a month ago...i was getting a P0300 engine misfire dected code. The truck was running extrenely rough. ANyway, my problem turned out to be a clogged cat converter and a faulty O2 sensor. Unless someone else has a better solution, I would take it somewhere (unfortunately).

 

If this is the problem; depending on how many miles you have on your truck, this may be covered under warranty...the emissions warranty is for 8yrs/80,000 miles and covers the cat converter and O2 sensor.

just something to think about...I don't know if this is your problem or not and I am not saying it is. But I do remember that the mechanic that fixed mine said cylinders 1,3,5,7 was misfiring.

 

Hope eveyrthing works out for you.

fatluke Enthusiast

fatluke

Posted
  • Author
Posted
I had the same thing on my 2003 about a month ago...i was getting a P0300 engine misfire dected code. The truck was running extrenely rough. ANyway, my problem turned out to be a clogged cat converter and a faulty O2 sensor. Unless someone else has a better solution, I would take it somewhere (unfortunately).

 

If this is the problem; depending on how many miles you have on your truck, this may be covered under warranty...the emissions warranty is for 8yrs/80,000 miles and covers the cat converter and O2 sensor.

just something to think about...I don't know if this is your problem or not and I am not saying it is. But I do remember that the mechanic that fixed mine said cylinders 1,3,5,7 was misfiring.

 

Hope eveyrthing works out for you.

 

 

Yes I have the same problem. 1,3,5,7 miss firing... Looks like I will leave this one to the professionals. I was considering changing the coil packs, but it doesn't make sense to me that all coil packs on the one side would go. That is why I was asking if there is something else that drives the coil packs. I am by no means mechanically inclined, but as far as switching parts and stuff like that I can do.

 

I will mention this to the mechanic about the cat and o2 sensor.

 

Did the O2 sensor not show up on the scan??

fatluke Enthusiast

fatluke

Posted
  • Author
Posted

One thing I forgot to mention. This started happening about 5 minutes after a car wash. The mechanic thinks it may be coincidence, but I am wondering if the car wash has something to do with it.

rgdepew Enthusiast

rgdepew

Posted
Posted
One thing I forgot to mention. This started happening about 5 minutes after a car wash. The mechanic thinks it may be coincidence, but I am wondering if the car wash has something to do with it.

Its a good possibality.

 

Just a fair warning about those coil packs though...they are about $100 a pop.

fatluke Enthusiast

fatluke

Posted
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Thanks for the warning... god d**n!!!.. That is why I was hoping I could figure this out myself.. to save a couple dollars....

 

Does anyone see it possible that all 4 coild packs would go on that side? Or is there something else that drive all the coil packs???

 

Thanks in advance!!

98 Z71 SLT Senior Enthusiast

98 Z71 SLT

Posted
Posted

Man...I'm gonna have to say intake gaskets on this one.

Get yourself a can of carb cleaner. With the truck running at idle, spray carb cleaner all around the base of the intake manifold. If your rpm's fluctuate...that's your problem.

 

I work at a GMC dealer...and we have seen alot of intake gasket issues recently.

 

BTW...you can easily fix this yourself at home.

fatluke Enthusiast

fatluke

Posted
  • Author
Posted
Man...I'm gonna have to say intake gaskets on this one.

Get yourself a can of carb cleaner. With the truck running at idle, spray carb cleaner all around the base of the intake manifold. If your rpm's fluctuate...that's your problem.

 

I work at a GMC dealer...and we have seen alot of intake gasket issues recently.

 

BTW...you can easily fix this yourself at home.

 

 

Thank you very much.. I will give that a try and will report back a little later!!!!

Rammer Enthusiast

Rammer

Posted
Posted

All of the coil packs on one side of the engine use the same ground and power. I'd start with the grounds. Check all wiring and connectors on both the power and ground.

 

2048760_15_full.jpg

mcreyaufmiller Senior Enthusiast

mcreyaufmiller

Posted
Posted

Agreed, look to the coil conntctors. I would check the power connector that connects the entire bank first. Unplug the connection and make sure the plug is dry. If by chance you washed the engine and got water in the conntctions this could cause the mis on the entire bank. I do not believe the entire bank would go out at the same time. There has to be another answer. The cat thing may make sense if you have dual cats on your truck, otherwise not so much. If you do find out that it is your power plug, I weould reassemble the plug with dielectric grease to keep water from getting in again.

fatluke Enthusiast

fatluke

Posted
  • Author
Posted

Rammer..

 

Thanks a lot for that diagram.. It will be a big help. I am going out to check grounds and power now...

 

I have a multi meter, if I should be testing anything with it?????

fatluke Enthusiast

fatluke

Posted
  • Author
Posted
All of the coil packs on one side of the engine use the same ground and power. I'd start with the grounds. Check all wiring and connectors on both the power and ground.

 

2048760_15_full.jpg

 

OK.. SO I am not an electrical engineer or anything.... but where on the diagram is the ground and the power???

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