# Check engine light blinking



## ChevyHDkid45 (Nov 30, 2008)

I have a 2002 chevy 2500hd with the 6.0 when i go through a car was about halfway through the engine light starts blinking. I dont have any engine lights doing regular driving. It happened to me once in a heavy heavy down poor a couple months ago. Once i am out of the wash the engine lights stops no weird idling or anything during the blinking. Has anyone ever had this happen or know why its doing it and what is a solution to the problem.. Please let me know it would be great.


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## brad96z28 (Aug 21, 2005)

Ck the code but I bet ur knock sensor is swimming!


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## mayhem (Aug 25, 2006)

One of your engine's coilpacks is getting wet and shorting out.


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## brad96z28 (Aug 21, 2005)

Um I think He would feel it if he had a coil messing up. Single coils not coil pack on a 6.0


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## Cosmic Charlie (Feb 1, 2009)

My 2002 does it on the highway over 60 MPH for 4 years - and truck runs fine - was told could be bad ground - coils all checked out fine - so I live with it ... GM says flashing check engine light means "Engine Misfire"

it ends up leaving the check engine light on afterward so at inspection sticker time, I just have auto zone shut it off and drive around town (not highway) for a few weeks and the truck passes inspection

a half ass way to deal with it - but it works ...


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## tim096 (Dec 24, 2007)

Flashing engine light means damange to the cat. converter is happening. 99% of the time it is due to an engine miss. Any good scanner should be able to tell you what cylinder is missing. If it only misses when it is raining try squirting the wires and coils with water and look for the sparks. Hope this helps


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## mayhem (Aug 25, 2006)

brad96z28;1086015 said:


> Um I think He would feel it if he had a coil messing up. Single coils not coil pack on a 6.0


My bad, thought it had individual coilpacks. Wife's Audi V-6 does and had this same symptom, dealer replaced under recall.


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## ChevyHDkid45 (Nov 30, 2008)

I dont understand why it just randomly starts happening... I have been going through the same carwash for a long time. it never did it before in rain sleet or snow. Any recomendations on just fixing the problem? should i to a mechanic or is it somthing i can try to diagnose by myself?


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## brad96z28 (Aug 21, 2005)

ChevyHDkid45;1087213 said:


> I dont understand why it just randomly starts happening... I have been going through the same carwash for a long time. it never did it before in rain sleet or snow. Any recomendations on just fixing the problem? should i to a mechanic or is it somthing i can try to diagnose by myself?


Like said many times get it scanned and we can help other wise this is going to be another 4 page it could be it might be it maybe. If u want 400 guesses please continue Get it scanned and we can let u know what to do from there. At this point maybe u should take it to someone that knows where to begin.:crying:


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## Cosmic Charlie (Feb 1, 2009)

Like I said

Mine does it on the highway ONLY - over 2300 rpms (+-) - been told it's a bad ground somewhere - no one can find my problem - over 4 years with no other issues - yours may be a different problem ... 

my truck runs fine except on the highway it flashes ... but runs fine --- for 4 years 

chase it if you want ---

lots of things to chase ........................................................

put your truck in park and rev the engine to 2500 rpms for a few minutes, and see if it does it (flashes) like mine - even with that repeatability, no mechanics can figure mine out ... my coils packs checked out ok even with the light flashing -- go figure

and then let me know ...


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## mycirus (Dec 6, 2008)

Cosmic Charlie;1086084 said:


> My 2002 does it on the highway over 60 MPH for 4 years - and truck runs fine - was told could be bad ground - coils all checked out fine - so I live with it ... GM says flashing check engine light means "Engine Misfire"
> 
> it ends up leaving the check engine light on afterward so at inspection sticker time, I just have auto zone shut it off and drive around town (not highway) for a few weeks and the truck passes inspection
> 
> a half ass way to deal with it - but it works ...


Mine does the same thing, throws the code misfire mult cyl. I have tried plugs, wires, and throttle body cleaning, and injector service and it still does it. Runs mint, dont feel any loss of power. I am living with it too.


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## mayhem (Aug 25, 2006)

ChevyHDkid45;1087213 said:


> I dont understand why it just randomly starts happening... I have been going through the same carwash for a long time. it never did it before in rain sleet or snow. Any recomendations on just fixing the problem? should i to a mechanic or is it somthing i can try to diagnose by myself?


FYI, you can get the codes read for free at most auto parts stores. Get the code and then post them back here.


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## deere615 (Jun 1, 2007)

Cosmic Charlie;1087223 said:


> Like I said
> 
> Mine does it on the highway ONLY - over 2300 rpms (+-) - been told it's a bad ground somewhere - no one can find my problem - over 4 years with no other issues - yours may be a different problem ...
> 
> ...


I had that on mine they said the timing chain had a little play in it and reprogramed something in the computer and no eninge light so far


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## brad96z28 (Aug 21, 2005)

deere615;1087320 said:


> I had that on mine they said the timing chain had a little play in it and reprogramed something in the computer and no eninge light so far


Very common. Includes doing ckp relearn procedure.


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## brad96z28 (Aug 21, 2005)

Cosmic Charlie;1087223 said:


> Like I said
> 
> Mine does it on the highway ONLY - over 2300 rpms (+-) - been told it's a bad ground somewhere - no one can find my problem - over 4 years with no other issues - yours may be a different problem ...
> 
> ...


Does urs only do it when wet like his I guess not?


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## brad96z28 (Aug 21, 2005)

mycirus;1087230 said:


> Mine does the same thing, throws the code misfire mult cyl. I have tried plugs, wires, and throttle body cleaning, and injector service and it still does it. Runs mint, dont feel any loss of power. I am living with it too.


I will fix it ! Have not had one yet I could not.


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## deere615 (Jun 1, 2007)

brad96z28;1087328 said:


> Very common. Includes doing ckp relearn procedure.


yeah thats what I heard but I was wondering if that meanes my timing chain is getting bad?


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## B&B (Nov 4, 2006)

brad96z28;1087328 said:


> Very common. Includes doing ckp relearn procedure.


If the tuneup is good, the EGR is working correctly (if equipped) then a crank re-learn will 95% of the time fix a STEADY STATE highway speed misfire detection. I consider a crank re-learn as a good preventative maintenance procedure every few years as the engine ages....too bad more persons don't. Would save customers much greif and money chasing ghosts that aren't there. I'm sure you'd agree.

I generally do them about every 30K or so during a regularly scheduled PM. Takes a whole 2 minutes anyway.


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## Cosmic Charlie (Feb 1, 2009)

*Crank Relearn*

Too bad you can't do mine, or can you ?

I would pay you if you could ....

I'm at zip 01985


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## deere615 (Jun 1, 2007)

B&B;1087377 said:


> If the tuneup is good, the EGR is working correctly (if equipped) then a crank re-learn will 95% of the time fix a STEADY STATE highway speed misfire detection. I consider a crank re-learn as a good preventative maintenance procedure every few years as the engine ages....too bad more persons don't. Would save customers much greif and money chasing ghosts that aren't there. I'm sure you'd agree.
> 
> I generally do them about every 30K or so during a regularly scheduled PM. Takes a whole 2 minutes anyway.


A whole 2 minutes that I got charged a whole $300 for??


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## brad96z28 (Aug 21, 2005)

Cosmic Charlie;1087390 said:


> Too bad you can't do mine, or can you ?
> 
> I would pay you if you could ....
> 
> I'm at zip 01985


Yes zip 02780
What year is ur truck?


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## B&B (Nov 4, 2006)

Cosmic Charlie;1087390 said:


> Too bad you can't do mine, or can you ?
> 
> I would pay you if you could ....
> 
> I'm at zip 01985


Might be a little cost prohibitive, about a 1000 mile round trip for you so you may want to hit Brad up instead. But at least you'd know it was fixed for sure until you got home. 

Anyone with a good bi-directional control capable scanner and a little knowledge on how to use it can do the procedure. Doesn't have to be a dealer only thing so cost is generally minimal.



deere615;1087393 said:


> A whole 2 minutes that I got charged a whole $300 for??


Don't know what all you had done but yes it's a two minute job. I don't even charge for it if I do it during a routine service as I usually have the scanner out checking for any pending issues anyway.


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## Cosmic Charlie (Feb 1, 2009)

brad96z28;1087400 said:


> Yes zip 02780
> What year is ur truck?


2004 Chevy Sliverado 2500 HD 6.0 Gas, 101,000 miles original owner ...


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## brad96z28 (Aug 21, 2005)

B&B;1087377 said:


> If the tuneup is good, the EGR is working correctly (if equipped) then a crank re-learn will 95% of the time fix a STEADY STATE highway speed misfire detection. I consider a crank re-learn as a good preventative maintenance procedure every few years as the engine ages....too bad more persons don't. Would save customers much greif and money chasing ghosts that aren't there. I'm sure you'd agree.
> 
> I generally do them about every 30K or so during a regularly scheduled PM. Takes a whole 2 minutes anyway.


Yes I agree. The first I saw one was a tricky one. U can graph the misfire on the tech 2 watch multiple misfire and with a simple ckp re learn all gone. After cking the basics first ofcourse. Kind of sorta like the aftermarket dist caps on vortec style motors With the po 300 those thing would trow, again misfires that u could never feel. Install a delco cap All the misfires would disapear. I have never used an aftermarket cap on a vortec after fixing tons of them that others could never figure out. Common knowledge now Im sure.


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## brad96z28 (Aug 21, 2005)

Cosmic Charlie;1087408 said:


> 2004 Chevy Sliverado 2500 HD 6.0 Gas, 101,000 miles original owner ...


Yes not a problem. U might want to find someone closer though. But I would be glad to do it.


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## brad96z28 (Aug 21, 2005)

My genisys Wont do it 90% of the time And have 2 of those. It Is scary when It wont do. lol no fuel cut out, Even though It shows that It will, It wont. I have read that others have the same problem with that tool.


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## Cosmic Charlie (Feb 1, 2009)

brad96z28;1087419 said:


> Yes not a problem. U might want to find someone closer though. But I would be glad to do it.


I'll ask my mechanic about it ...

Thanks for the info


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## brad96z28 (Aug 21, 2005)

Let us know.


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## B&B (Nov 4, 2006)

brad96z28;1087427 said:


> My genisys Wont do it 90% of the time And have 2 of those. It Is scary when It wont do. lol no fuel cut out, Even though It shows that It will, It wont. I have read that others have the same problem with that tool.


Used to have an old Snap-On MT2500 that would do the same thing. Blow right through the fuel cut off and oh #@^* .

Have had the newest Genesis (EVO) for a good while now and haven't had anything it couldn't do the re-learn on....yet. If I find one then it's back to the old trusty Tech2 I go.


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