gbkd80

So, I left a parking lot today and immediately the Jeep started chugging and running lousy. Then the engine light came on. I drove it home immediately and got my other car, but from what I'm reading people are saying that's a really bad sign... I'm going to scan it tonight with my Actron and see what's happening. Just wanted a thread to follow while I figure it out. I'll post the results.

I changed the oil and filter last week. Tightened down the valve cover bolts because whoever was in there before changing the gasket left them too loose....

I did Seafoam the engine through the intake about a week after I got the Jeep, so about a month ago. Doing so definitely damaged the oil sending unit and I'm getting the check gauges light on the dash. But I'd like to hope whatever is happening is because of my screw up and not some random thing...

The only different thing about this parking lot I left from was it was on a slight decline, so I was parked dipped downwards a bit, if that has anything to do with anything...

PatHenry

Flashing CEL is a major problem. I would be stunned and amazed if the sending unit could trigger the severe CEL condition.

The only time I had a flashing CEL was when a valve spring broke in my TJ.

Get that code and don't drive it until it's resolved! Keep us posted please.

gbkd80

Will do...

I wouldn't assume the sending unit caused the CEL flash. I was just figuring Seafoaming the engine might have gunked things up worse.

tech

When the CEL flashing there is a miss fire at that time . you could have a problem with coils spark plugs or even a fuel injector . get the code it should tell you what cylinder is miss firing and go from there .

PatHenry

I doubt the seafoam has anything to do with the issue. If anything, it might have exposed an existing issue that was on the brink of occurring anyway (like a bad injector).

tjwalker

Post the exact code (not just a description) and we can go from there.

Know that a flashing check engine light indicates a "serious misfire" which if not resolved ASAP, will trash your catalytic converter. Don't drive it like this.

Good luck and keep us posted!

gbkd80

My Actron Pocketscan pulled up a P0303, but it doesn't indicate what cylinder is misfiring.

It's a chinsy little scanner but it usually at least gives the cylinder... in this case as I scroll through each screen it's reading like this:

P0303
MIL ON
MONITORS
0 INC
7 READY
MISFIRE
FUEL
COMP
CATLYST
EVAP
02 SENSOR
02 HTR

Any sense out of this data? I do recall it showing which cylinder misfires back when I used this thing on an old VW...

tech

The code is for cylinder #3 miss firing if you had a po300 code that is a random miss fire , the code tells you witch cylinder is miss firing . check # 3 cylinder spark plug , the coils are working you need to change the coils because it is all one piece , also check the injector .

gbkd80

The injector just on #3?

Thank you, BTW...

gbkd80

Could this have anything to do with the heat soak around that area and the funky heat shield? I just YouTubed the crap out of it...

gbkd80

gbkd80

tech

That sounds like you fixed it .