2008 GMC Sierra- Check Engine Light and Observations

[Dantheman-2003]

2008 GMC Sierra 1500
Engine 5.3
Mileage 185k

This has been a great truck with minimal issues. I recently changed fluids, and installed new spark plugs and wires. It’s been running great. Today I drove to work and parked. When I got in to leave, the check engine light came on solid and idle was rough. Went to drive out the parking lot and CE light started flashing. Feels like something is misfiring, or something out of balance at idle. I’m sure it could be a handle full of things, coil pack, throttle body etc. or worse. I guess I need to check the codes and see what’s up for starters. Any advice would be appreciated.
Thanks,
Dan

 

[Doubeleive]

check your work, check your plugs and wires.
flashing cel means misfire, but either read the code or get it read to possibly narrow it down
if the plugs were not torqued correctly or wires not installed properly it could be as simple as that.

 

[Dantheman-2003]

check your work, check your plugs and wires.
flashing cel means misfire, but either read the code or get it read to possibly narrow it down
if the plugs were not torqued correctly or wires not installed properly it could be as simple as that.

Good points. And that’s my first starting point this morning. We’ll see what the day brings. Definitely going to pull the codes.

 

[Dantheman-2003]

10:30am: scan code reading P0302… cylinder misfire. I went back and checked all my plugs and wires. All tight and looked good. Maybe coil pack?

 

[mikez71]

Standard cab

10:30am: scan code reading P0302… cylinder misfire. I went back and checked all my plugs and wires. All tight and looked good. Maybe coil pack?

Cylinder 2? try swapping wires then coilpack..

 

[Dantheman-2003]

I lucked out. Cylinder 2 I pulled the plug and found a crack in it. $8.00 new plug, runs like a champ. Now I need a scan tool to clear the code. Anyone have recommendations for this,?

 

[Geotrash]

I have this one that I take on the road. It can read all of the proprietary modules on the truck and reset the codes.

iCarsoft i900 General Motors Gm Obd2 Car Truck Diagnostic Scanner Tool Reset Erase Fault Code https://a.co/d/aiXybmz

I also have this one and you can download the reader pack for GM and other makes but it’s subscription based. Also works well.

https://a.co/d/etTqDTt