How to Install Diesel Glow Plugs

  • 2-4 hours
  • Intermediate
  • 150-300
What You'll Need
Socket Wrench Set
Deep Well Sockets
Socket Extension
New Glow Plugs

Diesel glow plugs are what diesel engines use instead of the spark plugs used by gasoline-powered engines. For whatever reason, if you need to install new plugs, you do not need to hire a professional to do this job. All you need are simple tools and a couple of hours in order to remove and install new plugs.

Step 1: Preparation

Since you will be working with electrical components of the vehicle, you must follow standard safety precautions as you disconnect the battery. Remove the cable from the negative terminal of the battery. Do this by using the appropriate wrench to loosen the nut at fastening the wire to the negative terminal. When this is done, the clamp should slide right out.

Step 2: Remove Valve Cover

If your car has a valve cover, you must first remove it. Usually there are screws on all four sides of the valve cover. Get your tools and loosen and remove these screws. Set the screws aside once they have been removed. The valve cover should be free and you will be able to easily lift it off, exposing the engine head.

Step 3: Remove Glow Plug Cables

Diesel glow plugs cables are similar to spark plug cables. They are also connected to the glow plugs which are found inside the engine head. Remove the glow plug cables by simply pulling them off. Be careful in pulling them, since you don’t want to damage the rubber seal at the end of these wires. Remove all the glow plug wires that you see connected to the cylinder head.

Step 4: Removing Old Glow Plugs

You will now have access to the diesel glow plugs. You simply have to twist them counter-clockwise to remove. However, just like most spark plugs, you will need deep well sockets and socket wrenches for this. Connect the deep well socket to the socket wrench and insert it into the hole where the diesel glow plugs are. Get a firm hold on the plugs and when you do, turn the wrench counter-clockwise in order to remove the plug. Keep on turning until the plug eventually comes loose. When you pull the deep well socket out of the hole, it should bring the plug along with it. Do this same step to the other glow plugs. Take note of how the plugs are positioned, since you will be installing the new ones in this same manner.

Step 5: Installing New Glow Plugs

Now that you have removed the old plugs, install the new ones by simply attaching the glow plug to the end of the deep well socket and fit it into the hole. Remember the position you took the old plug out from and insert it in the hole the same way. Turn the wrench clockwise to tighten the plug. Do the same to the other diesel glow plugs.

Step 6: Reconnecting the Cables

Reconnect the cables to the plugs and make sure that they are secured well to the glow plugs. Simply push them back in and that should do it. Reconnect your battery and turn on your engine to test your newly installed diesel glow plugs.