My AutoPlace

Glow plug warning light: what it means and what to do

Orange coil or spring symbol. Diesel cars only.

Book this weekSafe to keep driving for now, but get it checked this week.

On a diesel car this coil light shows the engine is pre-heating. It normally goes out within a few seconds. If it stays on, or flashes while you drive, the engine has found a fault and may be running with reduced power.

What it means

Glow plugs warm a diesel engine so it starts in the cold. The light comes on for a moment before you start the engine. A light that stays on afterwards points to a glow plug, its control unit or another engine fault.

Can I keep driving?

Usually yes, but power may be reduced. Get it checked this week.

What to do now

  1. Wait for the light to go out before you start the engine on a cold morning.
  2. If it flashes or stays on while driving, book a check this week.
  3. If the car also shakes, loses power or smokes, have it looked at as soon as you can.

Common causes

  • Worn glow plugs
  • A faulty glow plug control unit
  • Another engine or sensor fault
  • A weak battery

Shops near you that can check this

Closest first. Your location stays on your phone.

Car Lab

Auckland CBD

Mechanics · WOF stations

Free written quote, or call to book

CallSee shop

M Tech

Henderson

Mechanics

Free written quote, or call to book

See shop

AZ Autos

Papatoetoe

Mechanics · WOF stations

Free written quote, or call to book

See shop

AB Autos

Panmure

Mechanics · WOF stations

Free written quote, or call to book

See shop

Fredco

Kingsland

Mechanics · WOF stations

Free written quote, or call to book

CallSee shop

VIRLTD

Onehunga

Mechanics · WOF stations

Free written quote, or call to book

CallSee shop

See all mechanics in this suburb

Questions drivers ask

Can I drive with the glow plug warning light on?

Usually yes, but power may be reduced. Get it checked this week.

What does the glow plug warning light mean?

On a diesel car this coil light shows the engine is pre-heating. It normally goes out within a few seconds. If it stays on, or flashes while you drive, the engine has found a fault and may be running with reduced power.

What should I do when the glow plug warning light comes on?

Wait for the light to go out before you start the engine on a cold morning. If it flashes or stays on while driving, book a check this week. If the car also shakes, loses power or smokes, have it looked at as soon as you can.

Need a tow? Call now

If anyone is hurt or you're in danger, call 111 first. Get off the road and wait behind the barrier.

Call AA Roadservice 0800 500 222

Members and non-members can call. Have your location and rego ready.

Other numbers to try

  • Your insurer's roadside line. Many policies include a free tow, and it's on your policy card or app.
  • Your car maker's roadside assistance, if the car is new enough.
  • A local tow company. Search "tow truck" with your suburb, and ask the price before you agree.

Need it fixed after? Find a shop near you and call them.

Book

What for?

Free to book. The shop texts to confirm, and gives you a written quote before any work.