I recently had a misfire in cylinder 4 on my 2017 Chevy Cruz, so I replaced the spark plugs and ignition coils. However, after doing that, the car ran significantly worse. The engine light came on, the Stabilitrak warning lit up, and the RPMs were fluctuating wildly when I pressed the gas. I even tried putting the original plugs back in while keeping the new coils, and it ran fine. The engine light hasn’t come back on after I cleared the codes, but I’m not sure if it’ll still misfire since it happened occasionally before. Has anyone else had issues with non-GM spark plugs in their Chevy Cruz or seen something like this? I just don’t get how new plugs could make it run so poorly.
Buy the gap tool. Make sure the plugs are the correct ones for your engine. If that doesn’t work, buy the same brand and spark plug number that you pulled out.
This is the correct answer.
Always check the gap on new plugs! They can be damaged in transit.
Noor said:
Always check the gap on new plugs! They can be damaged in transit.
I don’t have the tool to do it legit, but I was told by the person who sold me them they should go in fine without adjusting the gap. Though it wouldn’t be the first time a store clerk fed me misinformation.
To all the folks saying to gap the plugs: Modern platinum/iridium plugs are manufactured already set to a particular gap, as indicated on the package. Don’t attempt to adjust the gap as you would on old-school plugs.
@Mickey
Did you gap them properly?
They come pre-gapped, but I’ve had a few show up out of spec anyway. If you replaced all the coils with aftermarket ones, do yourself a favor and put the OEM ones back in. There’s just no need to replace them all at once.
@Isle
That’s what my dad told me too, modern spark plugs shouldn’t need to be gapped.
Did you get iridium ones?
Ellis said:
Did you get iridium ones?
The receipt says double platinum. AC Delco brand?
Get the AC Delco iridium plugs. And torque them to 18 lbs.