P0308 Engine Misfire on Cylinder 8

[optimus124]

Ok, fixed one thing....got another issue. I recently changed the thermostat due to a faulty one and the car was running great (no leaks what so ever). Today, the car started idling somewhat rough. I now got an error code of P0308. It's for a misfire on cylinder 8. Any suggestions?

Thanks

[fnkychkn]

try swapping the spark plugs;
#8a with #6a and #8b with #4b.

also swap ignition coils;
#8 with #2.

erase fault code and road test. recheck for codes. if the misfire followed a spark plug, change that plug. if it followed the coil, change that coil. if it stays on #8, check compression and perhaps a clogged injector.

good luck

[dudeiwin86]

do you have a predator?
first thing i would do is clear the trouble code/cel. and see if it coems back.
when was the last time you changed your plugs? and how many miles on the vehicle

[optimus124]

try swapping the spark plugs;
#8a with #6a and #8b with #4b.

also swap ignition coils;
#8 with #2.

erase fault code and road test. recheck for codes. if the misfire followed a spark plug, change that plug. if it followed the coil, change that coil. if it stays on #8, check compression and perhaps a clogged injector.

good luck

What's the count for the cylinders. I know its 8 but which is 1,2,3, etc. If it is a clogged injector, how do you go about fixing that.

do you have a predator?
first thing i would do is clear the trouble code/cel. and see if it coems back.
when was the last time you changed your plugs? and how many miles on the vehicle

Yeah I'm about 5-8K overdue for plugs. I did it last time at 39K and I'm at 72K now. I'll change that once she cools off. I didn't get time this weekend to do it, but I'll find time tonight

[Hemi31]

If you have that many miles on the plugs chances are they are fouling out.

[Fargo59]

ok, change the plugs, maybe rotate the coil packs, like fnky said. if the misfire is still present on cyl 8, then its an injector, mechanical, or a coil or injector driver fault. the last two are more likely to set different faults. if the misfire is on the cylinder you switch #8 coil with, then you know its the coil. mix and match, makes it easier to diagnose.

[fnkychkn]

What's the count for the cylinders. I know its 8 but which is 1,2,3, etc. If it is a clogged injector, how do you go about fixing that.

cylinders are numbered front to back; 1-3-5-7 on the left (driver's) side and 2-4-6-8 on the right (passenger's) side.
for a clogged injector, you might want to try getting them professionally cleaned.

[optimus124]

If you have that many miles on the plugs chances are they are fouling out.

cylinders are numbered front to back; 1-3-5-7 on the left (driver's) side and 2-4-6-8 on the right (passenger's) side.
for a clogged injector, you might want to try getting them professionally cleaned.

Yeah I looked around and didn't see a how to for that

Thanks for the help

[fnkychkn]

this write up is for an '05. coils are a little different but pretty much the same job.
Spark Plug Replacement 2005 5.7L *

[optimus124]

this write up is for an '05. coils are a little different but pretty much the same job.
Spark Plug Replacement 2005 5.7L *

MAN........YOU ARE GOOD!!!!

[fnkychkn]

MAN........YOU ARE GOOD!!!!

now you must pay me by updating your vehicle profile in your User CP.

[optimus124]

now you must pay me by updating your vehicle profile in your User CP.

Payment has been delivered. Well at least a bulk of it.

I don't know why, but I was thinking that the coils where something different. I need to get more sleep

[fnkychkn]

Payment has been delivered. Well at least a bulk of it.

thank you very much.
beans for you!

[optimus124]

Just a little update, I removed the plugs from cylinder 8 and inspected them. The plugs look somewhat worn, but no signs of a faulty plug. The coils look good also. I think its just time for some maintenence. BTW I switch coil from cylinder 8 with the one from 2, and swapped the plugs from 8a to 4a and 8b to 6b. I ran the car for about 10 minutes idle and no codes last night. I drove her this morning and the idle is not as smooth, but better. I already called NAPA and got 16 plugs waiting for me. I keep shocking all of the parts stores when I called and say that I need 16 plugs. Looks like I got at least an hour of my evening planned for tonight. I'm pretty optimistic, otherwise we'll see how well that lifetime warranty really holds up.

[optimus124]

Just an update. Gave my car some love this weekend:

Cleaned Combustion Chamber
Changed Sparkplugs (Copper)
Changed Oil
Cleaned CAI
Cleaned Engine Bay
Car Wash

Laila purrs like a kitten now. Looks like something on the preceeding list did the trick. Thanks again