Blinking Check Engine light

Colossus · February 23, 2020

how many miles?

Abeyance · February 24, 2020

8 hours ago, Colossus said:

how many miles?

213,000

Abeyance · March 12, 2020

Wasn't the intake manifold gaskets (or the knock sensors) either. After doing those, it now idles better, but the second you put it under a load (as in the second you put it in gear), it's just as bad as ever.

Pretty discouraged here, and out of ideas.

riverbanks · March 12, 2020

Intake was my thought too,does the motor skip from the second you start it? just thinking,open loop fine or not

Abeyance · March 14, 2020

On 3/12/2020 at 5:50 PM, riverbanks said:

Intake was my thought too,does the motor skip from the second you start it? just thinking,open loop fine or not

Following the intake gaskets, it starts and idles well enough that I thought it might be fixed. The second you put it in gear, it gets really rough.

riverbanks · March 14, 2020

Use a dowel or screwdriver,listen to the injectors,does any one sound different?

Abeyance · March 25, 2020

Well, looks like we were all wrong. Gave up and took it to a mechanic for diagnosis... just heard back, engine is bad. Will have more details once I pick it up. Not happy. Buying this truck was charity for a family member down on their luck and my reward is thousands out the window and nothing to show for it.

CamGTP · March 26, 2020

Engine is bad how?

That is what I'd be asking of the mechanic. Like a worn camshaft or like low compression on a cylinder?

Formulabruce · March 26, 2020

"The engine is bad" is a VERY Generic Term that sounds a lot like "Whatever" . When you have over 200K, and the mechanics cant even make book on diagnosis, this is the result.

While it might be cheaper to get a used engine with 150K , IF it really has a bad issue, I would want to know EXACTLY what is wrong. COP OUT is a good way to describe this.

davester · March 26, 2020

Yeah, I would expect a much more specific "diagnosis" than "the engine is bad" before shelling out for a new motor. Did a roll of Benjamins happen to fall out of your pocket while talking to this mechanic?

DonW · October 21, 2020

On 1/30/2020 at 1:43 PM, TedSJr said:

I have a 2003 2500 HD 4WD with 6.0 Gas V8. The check engine light periodically will begin blinking. It can blink for 2 minutes or for an hour, then it may quit for days. It has been doing this for months. My mechanic put it on the analyzer and got a Code 300. He said it is a misfire but he cannot pinpoint where. He suggested changing wires, plugs, coil packs, etc. Before I start replacing parts, does anyone have any thoughts? I've read where people say you should stop driving the truck immediately but, like I said, it has been doing this for a while and I have no problems in performance or gas mileage.

I literally just went through this. My CEL would flash at highway speeds. I read somewhere that the crank sensor could be flaking out at higher rpm. I replaced the crank sensor this afternoon and just took it for a hard test drive on the highway. No More flashing CEL! I also read that you need to do a crank sensor relearn after replacing it but right now, truck is running great so I think I’ll leave it alone. Hope this helps you!

Paul1823 · August 20

My 05 does the same thing…I replaced spark plugs and it ran great for a day…I replaced the coil packs and it ran great for a day again. I replaced the alternator and it ran great for 2 days. Wtf is up with these trucks?!?!?