Engine misfiring?

CORSA ENERGY

MEMBER
2018 VAUXHALL CORSA
1.4L
4 CYL
2WD
MANUAL
42,500 MILES

Last week I noticed a misfire when idling and a slight juddering changing gears which quickly got a lot worse. There were no warning lights, but I got it booked straight into a garage. They serviced it, oil change, new spark plugs etc. It has improved a lot since, but I still have a mild misfire when idling. Any ideas what this could be?

Thanks in advance!

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,924 POSTS

It sounds like you have an ignition coil going out, have you run the codes to see which cylinder is having the problem?

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This guide can help as well:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

A misfire in a vehicle can be caused by several factors, and it's good that you've already taken steps to address the issue by having the car serviced and the spark plugs replaced. Since the issue has improved but you're still experiencing a mild misfire when idling, here are a few additional factors to consider:

Ignition System Issues: While you've changed the spark plugs, there could still be issues with other components in the ignition system, such as ignition coils, ignition wires, or the ignition control module. These components can affect the spark quality and lead to misfires.

Fuel System Problems: Misfires can also be caused by problems in the fuel system, such as clogged fuel injectors or a malfunctioning fuel pressure regulator. If the fuel mixture isn't optimal, it can result in rough idling and misfires.

Air Intake Issues: A restricted or dirty air filter, a malfunctioning mass air flow sensor (MAF), or a vacuum leak can disrupt the air-fuel mixture and cause misfires.

Exhaust System: A clogged catalytic converter can lead to poor engine performance, including misfires. This might be worth investigating, especially if you notice reduced power or performance.

Sensor Malfunction: The vehicle's sensors, such as the oxygen sensors or the throttle position sensor, play a crucial role in maintaining proper engine performance. A malfunctioning sensor can affect fuel and air mixture and lead to misfires.

Compression Issues: Low compression in one or more cylinders can cause misfires. This could be due to worn piston rings, damaged valves, or other internal engine issues.

Engine Control Module (ECM): Sometimes, electronic control module issues can lead to misfires. This might involve the ECM not functioning optimally or not receiving accurate data from various sensors.

Please go over these guides and get back to us.