JLtheIrish

Hey there everyone,

I've recently run into a check engine light and have discovered that it is code P308 for a Cylinder 8 Misfire. I've tried to clear it a number of times but it comes back with a vengeance. I'm in a 2013 5L Fx4.
I just took it in to the maintenance shop and had no spark plugs put in (routine 96k FMPP replacement) and I had them try everything. The Plug Boots are not cracked and are clean, they replaced the coil for the #8 Cylinder and nothing improved.

Any ideas on what may be going wrong (technical breakdown much appreciated) with the engine? I'm pissing 4-5L/100km down the drain and drive ~500km a day. Service is booked for this coming Monday but I'd like to avoid it if possible!

Am3gross

Are you getting power to the coil? If its not firing and you have changed the plug and the coil pack it may be a broken wire somewhere...

RLXXI

The first thing they should have done was a compression check, no amount of fuel or spark is going to make up for a burned or bent valve or broken piston ring, hole in piston etc...

Have to determine base engine condition 1st. Compression test is that base starting point.

They need to check to see if the pcm is commanding injector pulse with a noid light.

The fact that none of these tests have been mentioned tells me you need to get your truck out of that shop and into a shop with a competent technician that will diag the vehicle and stop throwing parts at it.

.