Volkswagen glow plugs are flashing. Reasons and solutions

Your car is made with unique features such as warning lights on the dashboard that will signal you an issue occurring within the car’s mechanical functioning.

One of the most incredible light signal features you may see from time to time in your car is the glow plug light flashing. However, most of the time, drivers could see this flashing light of a glow plug light; they may panic with the idea their car is damaged or won’t work anymore.

Glow plug light flashing is a common issue, especially with Volkswagen TDI group car models that use diesel engines, and it leaves many drivers worried about their car.

But why is the glow plug light blinking in the dashboard?

Well, there are quite a significant number of reasons why glow plug lights will appear flashing on your car’s dashboard. The most common issue that causes glow plug light flash is when ECU detects a malfunction in the Engine Management Unit, resulting from coolant leaking, dirty oil, and worn glow/spark plugs.

In most cases, when a glow plug light is initiated, the car may enter into safe mode or limp mode to prevent further problems resulting due to engine malfunctioning. This is when your car may lose its performance power, although it will depend on the nature of the issue. As well, once the car gets into grow plug light flashing, there will be issues with fuel economy

A glow plug light appears like a coil flashlight and also can occur when the engine is cold, and it won’t be easy when starting. When the engine is cold, the car will use the glow plug to heat the combustion chamber (air in the cylinder) during the startup of the car, which in turn causes the glow plug light to start flashing.

After the engine gets heated sufficiently, the glow plug light on the dashboard will turn off, and starting the car becomes easy. 

However, if the coil light doesn’t stop flashing, there could be other issues that are causing the glow plug light to occur in that manner, such as timer fault. The timer controls the period the glow plug should operate, but if it is not functioning, it will allow the glow plug to continue igniting the engine, which will cause it to wear out.

What are the solutions to a flashing glow plug light?

Will you let an issue in your car continue threatening the entire health of your car? Of course not; therefore, if you have an issue with the flashing of the glow plug light in your car, get it solved.

Fixing a glow plug light flashing, you need a mechanic who will help you diagnose the real cause and provide the best solutions. It is a good idea to know what is causing the issue to take the next action. Meanwhile, here are the best solutions to fix issues with glow plug light flashing.

1. Fix the new timer controller

A timer controls the operating system of the glow plug to heat the engine; if it has developed a fault, it won’t be able to stop the glow plug once it completes heating the engine. Fixing a new timer will prevent the available glow plug from continuing when not needed, and the flashing light on the dashboard won’t be seen.

2. Replace the bad glow plug

If the glow plug light flashes due to a bad glow plug, you need to purchase a new one and get it fixed.

3. Fix issue with coolant leakage

Coolant leaking in the combustion chamber may result in the engine malfunction, which gets detected by the ECU sensor and initiates a glow plug light in the dashboard. Therefore if there is coolant leaking, get the right solution to stop leakage.

What are the symptoms of a bad glow plug?

Knowing a bad glow plug is easy; if you see any of the following symptoms with your car, straightway, you should know it is a bad glow plug.

  • The car is having difficulties when starting the engine
  • If there are misfires with the engine
  • When you see an engine light on
  • Black smoke coming through the exhaustion pipe

Can you drive with bad glow plugs?

You can drive with bad glow plugs, but you will experience difficulties operating your engine as bad glow plugs will downgrade typical performance.

A bad glow plug-in diesel engine will cause the engine to malfunction and make the engine experience issues like misfires and difficulty when starting.

Therefore, if you decide to drive with bad glow plugs, then be ready to face other consequences such as poor fuel efficiency and production smoke pollution on the road.

Can glow plugs cause loss of power?

When the glow plug is bad, it will cause the engine to misfire. When glow plugs develop faults, they won’t be able to help provide heat that will burn the diesel in the combustion chamber.

In return, the engine will misfire, leading to a loss of engine power. Here, the acceleration will decrease, and fuel economy will be negatively affected.

Can a faulty glow plug damage the engine?

A faulty glow plug won’t damage the engine, but it will lower its performance. When the glow plug develops faulty, it will lead to the engine’s misfiring as it won’t provide the heat needed to ignite diesel. If there is an absence of ignition, acceleration due to loss of power will be low, and the entire engine performance gets affected negatively.

How much does it cost to replace the glow plugs? 

Replacing glow plugs will cost you a higher amount than spark plugs found in petrol cars, although the fixing will vary depending on different factors.

For example, the material used to make it, the type of mechanic, dealers, and of course, the area you are in. Starting with the cost of the glow glug, which may cost from $50 to $100, and labor of up to $300, you may end up paying about $450 to $650 if you choose to replace all glow plugs available.


Taking care of your car will give a good driving experience all the time, and like any other issue affecting the performance of your vehicle, you need to find out the cause of the glow plug light flashing.

This kind of warning light occurs for nothing as it detects significant problems in the engine management unit, such as malfunctioning. If your car glow plug light is flashing, get a professional mechanic who will help diagnose the cause and give you the next action.

Scroll to Top