SOLVED: Another misfire chasing threads (2008 express van)

[Tonyv__]

Details
2008 Chevy express 3500 cargo van 6.0
58k miles. 8k running hours. No service history

So after last weeks fun with the wife’s MB. (I think it’s resolved). my work van started having a rough idle. Code reader says P0307 misfire cylinder 7 confirmed. So I went and changed out the spark plugs (gapped to .040) and new wires. And did a half ass compression test because I didn’t realize how tight everything was. I tested the back 4 cylinders. All within 175-180psi. After this. I have p0302 code. Cleared then it came back. And it’s actually noticeably worse than it was before I changed the plugs. Now it rough idles then hard shifts into 2nd gear when accelerating from stop. Where oh where do I go from here

I originally had plans to move the coils around to see if the misfire follows. But I didn’t even get that far. And now it has gone to cylinder 2

Any advice is greatly appreciated

 

[Tonyv__]

Solved. My mechanic is an idiot. (I’m the mechanic) Cylinder 2 is the absolute hardest cylinder to get to on these vans and when I pulled the spark plug. It had zero gap. I must of banged it around trying to get it threaded

 

[OR VietVet]

You beat me to it. I was gonna suggest you recheck your work since it only had the misfire code for the one cylinder when you started. Then after the work you had a problem on a whole other cylinder. The coil swap would have been a recommendation as well. Glad it worked out for you.

 

[Tonyrodz]

My express van is a pos too.

 

[OR VietVet]

My express van is a pos too.

Yea, I have seen you speak highly of that van before.

 

[Tonyrodz]

Yea, I have seen you speak highly of that van before.

It idles at around 450 rpms. Maybe the cats are clogged. Has the 4.8 with only 150,000 on it.

 

[grouch]

It idles at around 450 rpms. Maybe the cats are clogged. Has the 4.8 with only 150,000 on it.

Hook a vacuum gauge up to it. That will tell the tale of the exhaust condition. As for zero gap. You didn't bang your head on the plug from frustration did you?

 

[Tonyrodz]

Hook a vacuum gauge up to it. That will tell the tale of the exhaust condition. As for zero gap. You didn't bang your head on the plug from frustration did you?

No as far as I know, the gaps are fine. I did get the plugs from Amazon, so who knows if they're legit. Someone tested the cats for me--they're def clogged. I gotta hollow them out. I've changed the maf and the tb twice, thinking that was the issue--it's not. When I changed the plugs about 2 1/2 yrs ago I also changed to oem wires. Driving it home after buying it a P0300 popped up--and it's been haunting me ever since.

 

[OR VietVet]

No as far as I know, the gaps are fine. I did get the plugs from Amazon, so who knows if they're legit. Someone tested the cats for me--they're def clogged. I gotta hollow them out. I've changed the maf and the tb twice, thinking that was the issue--it's not. When I changed the plugs about 2 1/2 yrs ago I also changed to oem wires. Driving it home after buying it a P0300 popped up--and it's been haunting me ever since.

@Tonyrodz, I think he was referring to @Tonyv__ about the spark plug gap on #2 cylinder when he had changed plugs for a cylinder #7 misfire code and then had a misfire code for #2 and pulled plug and found it had a pinched gap.

 

[Tonyv__]

@PNW VietVet I might as well of smashed them on my head... before I bought the van I always wondered how would I service the engine..... there’s an engine cover inside the van.. except it takes 20 minutes to get to it.. you have to remove the passenger seat, remove 2 lower dash panels, remove cup holder/glove box assembly, then the actual cover comes off.... at this point I’m ready for a coffee/beer break