Diagnostics

Car Misfiring Or Shaking Under Load

For rough running, shaking, flashing engine lights and P0300-style fault codes.
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Llandow workshop, South Wales customers

Misfires need proof before parts

A misfire can be caused by plugs, coils, injectors, compression, fuel delivery, air leaks, wiring or ECU control. Replacing the most common part is not the same as proving the fault.

We use the symptom, scan data, cylinder information, live values and workshop checks such as smoke or pressure testing where appropriate before recommending the repair route.

Diagnostics

What happens next

You do not need to know the workshop term. Tell us the symptoms and we will explain whether the car needs servicing, fault-finding or repair work.

What we look at

  • P0300 and cylinder-specific misfire fault codes.
  • Rough idle, shaking, flashing engine light or poor acceleration.
  • Coils, plugs, injectors, compression, fuelling, wiring and air leak checks.
  • Misfires under load, at idle, cold, hot, in damp weather or intermittently.
If the problem points elsewhere

Other useful routes

Engine light or poor running

This is often the better route when the symptoms, service history or inspection point in a different direction.

Read more

Injectors

This is often the better route when the symptoms, service history or inspection point in a different direction.

Read more

Electrical fault or warning lights

This is often the better route when the symptoms, service history or inspection point in a different direction.

Read more
Not Sure What Is Wrong?

Tell us the symptoms and we will point you in the right direction.

If you are unsure whether the car needs servicing, fault-finding or repair work, start with the free first check.

Contact LT Servicing