So I was going to classes today and my car started vibrating really bad off of redlights and stops. On the way home on the parkway, it was much the same, and low acceleration and whenever I got over 50 I got a blinking CEL light.


When I got home, I ran a scan and I got P0300, random misfires. I took out my tester and tested the bottom coil (I forget the numbers), and wondered why they weren't showing anything. Then I tested the middle one and they showed 'ohm-age' and I tested the top one did as well. Other than the possibility of my ICM silently killing my coils, it seems that I have a single bad one, but I am here just to see if everyone else agrees.

If it is just the coil, which one should I get? Is there any difference? I'm assuming I don't want to get the cheaper aftermarket ones if I don't want to keep changing the same coil, right?

Do you have access to another 3.8 you could borrow a coil from for an hour or so?

No. I don't.

A bad coil should give you misfire on 2 cylinders, not a random, but I had single cylinder misfires show up as P0300 before, so it could very well be the coil. If you are getting significantly different readings off one coil, its too much of coincidence to ignore. I think you are on the right track.

I don't know enough about the difference between an E530C and a D555 to tell you which to use. Research it on AC Delco'* site.

Well, I'm getting absolutely NO readings on one coil

you may be better off getting low mileage used one from the jy, aftermarket delco stuff is questionable. i havent had anything from them last a third of what the oem stuff does lately.

I already ordered a new one from amazon. My thought process is to just get a new one instead of one that might already be dead or near dead...

But now that you put it that way, if this one dies, off to the junkyard for the next one

i havent had a gm one last less than 150k, im a little surprised at yours. if you drive in the city and the police probably did too it may have alot of hours on it, rather than miles maybe

i had my top two coils go at the same time. figured out i had a short in the icm and that basically melted the gel in there and ruined both. got them replaced with the an aftermarket brand and they have worked fine since.

Yeah, I try and not drive much in the city, but I think the police driving might've taken a toll on the ignition system of this car. The plug wires were really worn when I had them changed... one was holding on to a plug by a single strand. I know having this car through the winter last year was hell, and I think it was the gremlins left in the ignition system because of police abuse. Hopefully changing this coil will be the end... for a while.

Yeah, I see what you're saying. I actually have 2 icms since a mechanic insisted that my car wouldn't start because of my original one (it ended up being the CKP, as I told him.), so if it turns out to be the icm, I at least have another one to swap and try before I have to buy another one....