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How Much Does It Cost To Replace Glow Plugs?

Glow plug replacement costs in the UK range from £125 to £250. These small but essential diesel engine components ensure smooth starts, especially in cold conditions.

If your glow plugs fail, your engine may struggle to start, idle roughly, or emit excessive smoke. So, it’s key to keep an eye on them for a smooth drive.

Learn more about glow plug replacement and what to expect below.

Key takeaways

How much does it cost to replace glow plugs?

The average cost for replacing glow plugs in the UK is £170.

However, prices can range from £125 to £250 depending on your vehicle's make and condition. These costs include changing all of your glow plugs in one go.

The cost of glow plug replacement varies based on your vehicle and the manufacturer’s recommended parts. Additionally, the type of mechanic—whether a mobile mechanic or a dealership technician—can impact the total diesel glow plug replacement cost.

Looking for an Audi or VW Golf glow plug replacement cost? Here’s a quick overview of glow plug replacement costs per car manufacturer, looking at the approximate cost of parts and labour.

These costs may change depending on your car model and individual needs.

Car Make

Parts Cost

Labour Cost

Total Glow Plugs Cost

Audi

£80

£100

£180

BMW

£120

£160

£280

Ford

£130

£160

£290

Hyundai

£110

£140

£250

Mercedes-Benz

£90

£110

£200

Peugeot

£100

£120

£230

Toyota

£100

£180

£180

Volkswagen

£85

£105

£190

Glow plug replacement cost by location

Your location can also affect the cost of glow plugs.

How much are glow plugs at your local garage? Here are some average costs from across the UK:

Location

Glow Plugs Cost

Birmingham

£190

Glasgow

£190

Liverpool

£220

London

£215

Manchester

£200

How do I know if my glow plugs need replacing?

There are a few symptoms to keep an eye out for when it comes to replacing your glow plugs. These include:

  • Hard starting (especially in cold weather)

  • Excessive smoke from the exhaust

  • Glow plug warning light on dashboard

  • Decreased fuel efficiency

  • Engine misfiring or rough idling

If you notice any of these signs, it’s time to talk to a mechanic about a glow plug replacement.

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Glow plug symptoms and quick fixes

If you notice any of the symptoms above, it could indicate a problem with your glow plugs.

Here are some common problems and quick fixes to help you get back on the road:

Symptom

Quick Fix

Hard starting

Check battery health. If all is good, test glow plugs and replace as needed.

Exhaust smoke

Check for unburnt fuel issues. Inspect and replace faulty glow plugs.

Warning light on dashboard

Perform a diagnostic scan to identify faulty plugs or sensors, then replace them if needed.

Decreased fuel efficiency

Clean fuel injectors and check air filters. Replace any worn glow plugs.

Engine misfiring/rough idling

Inspect car wiring and connection for faults. Replace worn or damaged glow plugs.

Why are glow plugs expensive to replace?

Glow plugs can be expensive to replace due to the cost of the parts and the labour involved.

High-quality plugs for modern diesel engines are pricier, and labour costs can add up if they're hard to access. Some cars also require specialised tools, which can increase the overall cost as garages might need to import them or you might need to travel to a specialised mechanic.

How many glow plugs does my car have?

In most diesel vehicles, there’s typically one glow plug per cylinder. For example, a six-cylinder engine would have six plugs.

This can vary depending on engine size, manufacturer, or modifications. Always refer to your owner’s manual for specific details.

How often do glow plugs need replacing?

You should replace your glow plugs every 80,000 to 100,000 miles or when they show signs of failure. Driving conditions, maintenance habits, and the quality of the glow plugs can all impact their lifespan. It's wise to have them checked during regular maintenance so you can drive knowing they’re in tip-top condition!

How long does it take to replace glow plugs?

Replacing glow plugs typically takes 1 to 2 hours, depending on your car’s make and model.

Some engines are easier to access than others, affecting the overall repair time. Similarly, it may take longer if the glow plugs are seized or hard to reach.

Always factor in extra time and ask your garage for an estimated time frame to get a more accurate idea.

Are there any warning lights for glow plugs?

Many diesel vehicles have a glow plug warning light, usually a coil or spiral symbol. It lights up while the plugs heat and turns off once ready or the engine starts.

If glow plugs malfunction, the check engine lightmay also appear, although it can indicate other issues as well.

Jump to Bumper’s complete dashboard warning light guide now.

How long do glow plugs last?

Typically,glow plugs will last around 80,000 to 100,000 miles.

The accurate answer depends on your car's make, driving style, and material quality. Check your owner’s manual for answers, or contact the dealership for specific advice.

Are glow plugs covered under warranty?

It depends on your car’s warranty.

Many manufacturers' warranties cover glow plugs if they fail due to a defect but not if they wear out from normal use. Always check your warranty details for a clearer answer, or ask your dealer for specific coverage on glow plugs.

Can faulty glow plugs damage my engine?

Yes, faulty glow plugs can damage your engine. If they don't heat properly, the engine may struggle to start, leading to rough idling or misfires.

Over time, this can strain other parts, such as the fuel injectors and the starter motor, potentially leading to costly repairs.

Can I drive with faulty glow plugs?

No, it's not advised. Driving with faulty glow plugs can cause poor performance and engine misfires, putting you and others at risk.

If you must drive, keep the trip short and head straight to a mechanic.

How do I check my glow plugs?

Checking your diesel engine’s glow plugs is an important but simple part of regular maintenance. Before starting, make sure the engine is off and you're in a well-ventilated area for safety.

Follow these steps to begin:

  • Find the Glow Plugs — Locate them near or inside the cylinder head, one per cylinder.

  • Remove the Glow Plugs — Unscrew carefully with a socket wrench.

  • Clean or Replace — Remove carbon deposits and lubricate plugs before reinserting.

  • Reconnect Wires — Reattach any wires if applicable.

  • Start the Engine — Check that everything works properly.

Some models may need a special tool to remove glow plugs, so check your car’s requirements. Look for cracks, wear, or carbon buildup, and replace damaged plugs quickly.

Always refer to your owner’s manual and new plug instructions, and contact a professional if unsure about your glow plug replacement.

Conclusion

Hopefully, if you’re considering a glow plug replacement, this guide has helped you discover approximate costs and what to do next.

Don’t forget to check for glow plug symptoms and check whether your problem is covered under warranty before you consult a mechanic.

Visit the Bumper blog now to learn more.

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Words by

Alastair Shephard

Updated 15 Aug 2025

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