When, Why and How to Replace Your Mercedes Glow Plug?

Glow plugs are very important component of your engine as it helps in in ignition of fuel. Usually glow plugs in Mercedes last longer. But sometimes they get worn off due to many reasons. Here, in this article you will know when and how you have to replace the glow plugs in your Mercedes car.

Why there is need to replace the glow plugs?

First it is necessary to know what glow plug is and how it is useful. Glow plugs are devices used to heat the combustion chamber along with the fuel. It is a part of ignition system of the engine. Each cylinder has a glow plug. Its function is to hear the chamber. So by heating, it makes the work of spark plugs to ignite the fuel. There must be a right temperature for the process of ignition to undergo, these glow plugs brings that temperature to the combustion chamber.

The glow plugs work continuously while you drive your car. So with time, their performance might drop. They may get burned, damaged or worn out due to use of low quality glow plugs. In such case you have to replace the plugs with new ones. In hot weather, you may not need immediate replacement but in cold weather, your car will not start at all, it will roughly idle and you will have to replace it at any cost. Even if you able to start, your car will not run for more time, also driving in this condition is also extremely dangerous. So whenever you find the signs of a failing glow plug, it is better to take your car soon for replacement for glow plug.

When to replace the glow plug in Mercedes?

Hard starting of engine

If the weather is cold or in colder regions and you will be hard starting the engine. The culprit is the glow plug. A faulty glow plug will not able to ignite the fuel when the combustion chamber is colder.

Rough idle with smoke

Your car will idle roughly and produce a white smoke from exhaust while starting the engine. You will find it harder to start the engine. Burned out glow plugs is the reason.

Drop in fuel efficiency

In winter, you will find the fuel efficiency is decreased. The performance of the engine also becomes low.

Smoke from exhaust

In cold weather you will find white smoke from exhaust due to inability of glow plug to burn the fuel properly. If you get such sign check the fuel injectors and the injector pump because these components can also be culprit along with glow plugs.

If the weather is not so cold, you will find black smoke from exhaust due to wrong fuel air ratio in the fuel mixture. The performance of the car will drop.

Misfiring

Misfiring in engine can be caused due to faulty glow plug or fuel injector. If the glow plug is bad then it will not able to heat the combustion chamber to bring it to right temperature for ignition.

Is it safe to drive if glow plugs are faulty?

It is possible to drive but it is highly unsafe. Driving more in this condition will cause a great damage in the engine and you will have to spend much money to repair it. So avoid driving if you get the engine warning light and any of these signs of faulty glow plug

How to replace a glow plug in your Mercedes?

To replace a glow plug first you need to have a new glow plug, glow plug pre-chamber reamer and a smart wrench of 8mm to 12mm. Use a good quality glow plug which is recommended for your model.

1. First remove your injector hard lines and then use your wrench to remove a small nut which connects the wire to the top of glow plug.
2. Pull out the wire from the plug and rub the ends of the wire with sand paper if it is corroded. Rub until you will see the shiny metal of the wire.
3. Remove a glow plug by using the wrench to loosen it. Then check and test the plug to know if it is faulty or not. Remove all the glow plugs in this way.
4. Ream the opening by using the glow plug reamer in the pre-chamber to remove the carbon. Removing the carbon will make the new glow plugs to work properly.
5. Before reaming, coat the reamer blades with transmission fluid to pull out excess carbon easily. The reamer is pushed to the cylinder while turning it, it is done until the reamer stops turning, then take it out.
6. Install the new plugs into the chamber after completion of reaming. But before installing the plugs, these should be tested well.

Conclusion

I have share the easy way to get the plugs replaced. Now to must have known how important is glow plug and when to replace it. Generally it is recommended to change glow plugs once for every 100000 miles.

Since 1969, Dell’s service center has been providing relentless service to German & European made vehicles such as Audi, BMW, Mini Cooper, Volkswagen, Mercedes, Porsche, Land Rover, Jaguar, Saab, & Volvo in Green Bay, Appleton, and Sturgeon Bay.