TMM Mobile Vehicle Repairs 07989 747065

Engine misfire: diagnosis and repair

Juddering, shaking at idle or a flashing engine light? We find which cylinder is misfiring and why, and fix it where the car is parked.

Call 07989 747065Get a quote
The engine bay of a sports car with the bonnet open

A misfire is when one or more of the engine’s cylinders fails to burn its fuel properly. The engine shakes or stutters, loses power and uses more fuel.

It is worth sorting quickly. Unburnt fuel can overheat and damage the catalytic converter, which is expensive to replace, and a misfire that is left usually gets worse. We trace misfires with dealer-level Autel and Snap-On diagnostics and fix them on your driveway or at work.

Signs of a misfire

Common causes

Most misfires come down to one of these, and the first two only apply to petrol engines:

  • Ignition coils

    A failing coil is one of the most common causes on petrol engines.

  • Spark plugs

    Worn or fouled plugs can’t light the fuel properly.

  • Injectors

    A sticking or leaking injector upsets the fuel mix, on petrol and diesel alike.

  • Air leaks

    A split hose or intake leak lets in air the engine can’t measure.

How we find it

Our diagnostics show which cylinder is misfiring and the live data around it. Then we test the parts on that cylinder, such as the plug, coil and injector, so we replace what has failed rather than guessing. If the tests point to something mechanical, such as low compression, we explain what it means and what the options are before any work starts.

Flashing engine light?

Pull over when it is safe and call us on 07989 747065. Driving on with a heavy misfire can damage the catalytic converter. More about the engine management light.

Misfire questions

All questions

My engine warning light is on. Can I keep driving?

If the light is steady and the car drives normally, you can usually carry on gently and book a check soon. If it is flashing, or the car has lost power, is overheating or is making a new noise, stop somewhere safe and call us, because driving on can turn a small repair into a big one.

Can I drive with a misfire?

It is best not to. A misfire usually gets worse, and unburnt fuel can overheat and damage the catalytic converter, which is expensive to replace. If the engine management light is flashing, pull over when it is safe and call us.

Why does the misfire come and go?

Misfires that come and go are often down to an ignition coil or lead that breaks down in the damp or when it is hot, or an injector or sensor that behaves differently when the engine is cold. Tell us when it happens and we will plan the check around it.

Misfires fixed across the North West

We trace and fix misfires at home and at work in all of these towns.

All areas we cover

Book a misfire check

Tell us when the misfire happens, whether the engine light is on and where the car is parked. We will get back to you with a price and our earliest time.

Some evening and Saturday appointments available at no extra labour charge.

For example: engine light came on this morning and it feels down on power.
A photo of the warning light or the damage helps us give you a closer price.

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