02 Silverado 5.3L blinking Service engine light

[Gito]

2002 Chevy Silverado with approximately 310k miles. Original engine.

The service engine light has been on for at least one month.
The last code read a misfire (Pep Boys). I forget the code number but it was an Evaporator issue.
The code was cleared and so I went to smog the truck and it passed.

Code came back but I kept on driving.

Late Monday night I drove my truck down to the grocery store without any problems.
It was a cold night for CA (53 deg).

I started the truck to drive back home and then the Service Engine light started to blink.

I drove home for approximately 1 mile with the service engine light blinking.

Got home and turned off the truck.

Restarted the truck and the shaking and jumping was more pronounced.

I drove around the block (Service Engine light not blinking) and I could feel the truck running very rough.
I could still drive but it was a sign to park the truck.

I have plugs and wires on order.

I will try to get the code once I replace the plugs and wires.

Hopefully its something simple.

Please advise

 

[bioburner]

I had something close and it was a weak cylinder, bad valve. Was cheaper to find a low miles engine than getting the head fixed. Once you open a high miles engine it seems in my experience that the bleeding of the wallet won't stop. Good luck

 

[MarkM66]

"Please advise" us of what the code is.

 

[Trav]

Post the code, probably a ignition related P3xx or an injector fail and do not drive the truck until its fixed, a flashing CEL denotes a cat damaging event.

 

[mjoekingz28]

Originally Posted By: bioburner
Once you open a high miles engine it seems in my experience that the bleeding of the wallet won't stop. Good luck




That is funny!

But sad, since I think rebuilding it yourself is cool, keeping the original is cool, and it may run better since everything has broken in (or worn) together.

 

[fxrider]

You ever Clean the Throttle body or replace it? its got to be filthy by now.. I replaced mine at 75000 but I live on a dirt road & run a K&N filter..

 

[krismoriah72]

Probably intake gaskets..if not done yet.

Good time to replace the knock sensors and harness while u are in there.

Your codes will probably be multiple misfires.

 

[sasilverbullet]

Originally Posted By: bioburner
...Once you open a high miles engine it seems in my experience that the bleeding of the wallet won't stop. Good luck


+1

 

[FZ1]

Plugs first. Save the plugs. Then take the truck and the plugs to a chevy dealer for diagnosis.

 

[dishdude]

We don't even know the code and have the guy throwing parts at it.

 

[DoubleWasp]

A code flashing means that is a pending (active) code. Whatever initiated the code is literally going on at that moment.

 

[Trav]

https://www.carmd.com/wp/flashing-check-engine-light/

 

[bdcardinal]

I need to get a set of diagnostic dice or a diagnostic magic 8 ball for situations like this.

 

[Trav]

Naw just throw money and parts at it. The euphoria of placing the online parts order and visions of having the vehicle repaired like new again will carry you over for a few days but after hours of fruitless hard labor and failure the let down is merciless. The old emotional roller coaster rides again.

 

[javacontour]

Originally Posted By: DoubleWasp
A code flashing means that is a pending (active) code. Whatever initiated the code is literally going on at that moment.


Flashing code means stop now, you are experiencing something that will damage the engine or emissions control system.

A solid light means check it soon, but it's safe to keep driving.

Flashing means it is not safe for the engine to keep running.

 

[bdcardinal]

Originally Posted By: Trav
Naw just throw money and parts at it. The euphoria of placing the online parts order and visions of having the vehicle repaired like new again will carry you over for a few days but after hours of fruitless hard labor and failure the let down is merciless. The old emotional roller coaster rides again.

I love when customers come in and say they have a check engine line on and what should they get. I usually ask "did you run the code or have a mechanic look at it?" and the usual response is "no they wanted to charge me." Those are the big money tickets where no parts are returnable. I usually recommend they go to service as it will be cheaper than a shotgun diag or throwing parts at it until something sticks.

 

[nthach]

You don't have the troublesome Vortec CPI/CSPI "spider" EFI system on your truck that's the source of agony on the older GM trucks - nor the distributor that needs the cam/crank corelation(CMPRET) set to -/+ 3 degrees or a CEL will turn on. A friend's 98 Tahoe was misfiring for no reason dumping fuel down the pipes - and I was in the truck with him when I saw the CEL flash, turned out his dad had Midas "tune up" the truck, but they routed the wires within millimeters of the exhaust manifolds and that caused them to short out. The truck still passed smog this week - after replacing wires, getting the CMPRET adjusted just right and going over Midas' handiwork.

Check the plugs, gas-soaked plugs or carbon fouling indicate fuel system problems - it's not a bad idea to buy a spark tester that snaps in a wire in place of a regular plug to see if you got spark. In theory, if there's a problem with spark on one cylinder, fuel should be cut to that one to keep the cats intact but not always. GM used coil-near-plug on those engines, you still have wires. And wires will melt if they are too close to the exhaust.

 

[SatinSilver]

Had the cel come on in the 99 Accord. Had it read at Autozone which came back as a lean fuel condition. The guy at AZ said it could be all sorts of things and gave a bunch of examples. Took it to the dealer and was out of there for less than $100. There was a tsb for the fuel pressure regulator. Had the car 10 yrs/166k miles and that was one of the few issues with it. Never left me stranded.

 

[Gito]

Truck has not been driven since the flashing/blinking Service Engine Light.
I replaced the intake manifold gasket last year but did not replace the knock sensors.

I ordered spark plug wires and spark plugs and will replace them when they are delivered.

If truck starts fine I will drive to Pep B..s to run the codes.

If truck continues to shake I will get it towed to shop

 

[GMBoy]

Originally Posted By: DoubleWasp
A code flashing means that is a pending (active) code. Whatever initiated the code is literally going on at that moment.



A flashing CEL light means a severe misfire and a catalyst damage risk. Nothing to do with pending code. A pending code will not set the light on until it becomes current.