Revision question · Vehicle condition

In severe cold, what fuel problem can make a diesel engine run erratically?

Revision material from the imported DVSA bank includes source-checked Lanekind learning corrections. These corrections are not newly issued official examination questions, and practice does not reproduce a live test paper.

Answer options

The endurance brake engaging

The air conditioning not working

The speed limiter operating

The fuel partly solidifying

Show the answer

The fuel partly solidifyingThis was the right answer

Wax crystals can form in sufficiently cold diesel and restrict filters and flow, causing poor running or stopping. The temperature depends on fuel grade and treatment. Use suitable fuel and the specified cold-weather system; this is not a guaranteed diagnosis of every cold-running fault.

Reviewed reading for this question

Understand diesel waxing and approved cold-weather measuresReviewed guidance summary · The correction distinguishes wax crystals from water freezing and forbids unapproved additives.

Loading the questions