A few months ago my engine lost a cylinder number 8 . The engine had 170000 miles on her with the original plugs and wires. So I change out all that. Still bad miss number 8 cylinder. So I ran a compression check and had below 100 lbs. Thought maybe an injector. So I replaced all 8. Still had a number 8 miss. Checked compression and it came up to 125. I thought maybe tyhe injector washed the oil out of the cylinder. Thought maybe a weak coil .switched out the coil with a good cy;linder to see if the problem followed it did not. Same with plug and wire. Still a bad miss in number 8 . What am I missing or is there some other way to find out what my problem is. I use JPRO and it allowed me to cut the injector and check for drop. It did drop. Could a catalytic converter be bad. There was a lot of unburnt gas being sent out the exhaust
CK5
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2012 Silverado with vortec engine bad number 8 cylinder
- Thread starter 6.2 man
- Start date
I am thinking valve spring broke. time to pull the valve cover and inspect.
Yes unburnt fuel can and will damage a cat. If it were all the injectors leaking then the cat would be damaged for sure. Since it's sounds like you are going after the issue soon after symptoms showed, and only 1 cylinder, I think your cat should be ok for it's age. Do you have emission testing ? The rear o2 sensors will tell you when the cat is used up.
Yes unburnt fuel can and will damage a cat. If it were all the injectors leaking then the cat would be damaged for sure. Since it's sounds like you are going after the issue soon after symptoms showed, and only 1 cylinder, I think your cat should be ok for it's age. Do you have emission testing ? The rear o2 sensors will tell you when the cat is used up.
No emission testing yet I just need to know if something else could cause my number 8 not to work
Bad cat would effect whole bank, or all.
I think you narrowed it down well enough to look for a mechanical issue.
I think you narrowed it down well enough to look for a mechanical issue.
I have to agree. Look for valve / mechanical prob. Maybe even collapsed lifter.
Guarantee it lost a lifter and killed the cam.
Oh, man i hope not. But i guess your gonna find out. I've owned 5.3's since my first 99 z71, and never had a problem, so i hope yours is minor !
