What is the spark plug doing during intake?
During the intake stroke, the fuel and air mixture is drawn into the cylinder with the exhaust valve closed. Then the air and fuel mixture is compressed in a compression stroke. At the top of the stroke, the spark plug ignites the mixture.
How can I tell if my spark plugs are bad?
What symptoms may indicate my vehicle’s spark plugs need replacing?
- Rattling, pinging or “knock”-like noises. When spark plugs begin to misfire, you may notice unusual noises from the force of the pistons and combustion not working properly.
- Hard vehicle start.
- Reduced performance.
- Poor fuel economy.
Do you need to pull intake manifold plugs?
The coil pack harness connectors were a little difficult to release because of the little white locks that must be pushed back, and the release tabs are pretty small. But everything is visible and accessible if a little tight. Pulling the intake manifold would definitely provide more room, but I wanted to avoid that if possible.
Where do you change the spark plugs in a car?
For most vehicles, replacing spark plugs is a simple matter, though you might need to be a contortionist to get to some of them, perhaps placed behind shields or under intake manifolds and other equipment. Here are the basic steps to replace spark plugs.
Do you have to remove the intake on a GMC Di engine?
You do have to remove the intake on the DI engines (with the aluminum intake; not sure about the plastic one in 13+ models). It’s really easy to do, and once removed you can get to the plugs and coils very easily. Also, if you use the AC Delco iridium plugs, they’re made by NGK, which already has a plating on them so they don’t stick in the head.
How do you install new spark plugs on GMC?
I put a little anti-sieze on the threads and a dab of dielectric grease on the coil pack boots before installing the new plugs. All of them had correct gap right out of the box. I spun the plugs in by hand, using only the extension, to avoid cross-threading.