Home Technical Feature Winter Is Often When Glow Plugs Might Start To Cause Trouble

Winter Is Often When Glow Plugs Might Start To Cause Trouble

by Digital Mayne Media

In cold weather, often diesel engines can be difficult to start because the mass of the cylinder block and cylinder head absorb the heat of compression, preventing ignition, the glow plug is used to compensate for this heat loss.

Faulty glow plugs can make it difficult if not impossible to start a diesel engine on a cold morning. As you need to remove the glow plug to test it – this is often when you run into trouble.

The glow plugs are exposed to extreme heat, pressures, vibrations, and corrosive agents which develop during the combustion process. They may become seized in cylinder head recess thread due to moisture or debris entering via the thread. This can cause the glow plug to break at various points on the body when the plug is removed or alternately, the glow plug electrode (Tip) can on occasion swell over time and become stuck in the head and break off when the glow plug is removed,leaving the electrode in the cylinder head.

It can be helpful at times to try to unscrew the glow plug while the engine is still warm in preparation for removal.

Often just accessing the glow plugs to remove them for inspection and testing can be daunting – and this is where specialised tools come into their own. Specialist Tools Australia can assist you with selecting a kit that best suits your job.

GLOW PLUG SOCKET KIT
SA-1331K and SA-1332K have extra-long universal jointed glow plug sockets with a specialised puller and drills that suits most Japanese, Korean and European Diesel Engines. These special sockets enable access to difficult to reach glow plugs and the puller is fantastic for grabbing onto the glow plug in difficult to access places.

When testing glow plugs it is important that the test tool applies current load on the element, which is required to accurately check for faults. A multimeter will show correct continuity, but the current may break down when load is applied, giving an incorrect diagnosis of the glow plug.

MULTI VOLTAGE GLOW PLUG TESTER TOOL – SA-1053
This tool quickly and accurately test glow plugs, applying a current load on the element during testing ensuring a correct result.

The length and style of glow plug will often determine the type of tools you require with long thin glow plugs often causing the greatest issues.

When confronted with a broken or stuck glow plug, it is important to use the correct tool for removal, otherwise the issue can easily escalate, requiring the removal ofthe cylinder head or risk damage to other engine components. Glow plugs typically break at the head nut or at the tip which becomes brittle and distorted due to the heating as shown opposite.

Often you will unscrew the glow plug only to find that it is still stuck fast either on the body, thread, or the tip, depending on the style and length of the glow plug. Using a glow plug extracting tool (different styles found in a number of our Glow Plug removal kits) allows you to get a good strong hold on the head, or if that has broken off – the electrode may protrude –this will take a bit of force with some kits containing a slide hammer to give a good straight force reducing further breakage. If this doesn’t succeed you may need to drill out the broken plug down to where the threaded portion begins.

Drill out the glow plug body using a step drill – using a new plug to measure the depth required to drill out the old thread ensuring that all swarf is removed as you go. Then you can tap a thread into the inside of the glow plug body and using a cone extractor which is available in a number of our kits and shown in the SA-4296 kit. The cone style forcing nut enables easy extraction of the stuck glow plug.

SA-4296 COMPLETE GLOW PLUG EXTRACTION KIT
This kit removes 8mm and 10mm glow plugs found in many vehicles. The high-quality ratchet T-bar drill holding adaptor shows the superior quality of this kit compared to similar kits. The puller force screw with force nut taps into the glow plug for removal. It also has dual-size hightensile step drills m8 and m10 and pilot drill centring sleeves.

The set includes all tools required for drilling, centring and pulling glow plugs forefficient removal.

During this process you should continuously remove any metal shavings or carbon that is loosened so that it doesn’t become lodged in the glow plug recess or worse, the cylinder. To assist in this process, Specialist Tools Australia uses the Govoni insulated magnet shown in the universal kit and the Govoni dummy injector which blows air into the cylinder and out through the glow plug hole ensuring no rubbish is left in the cylinder. The glow plug recess should be thoroughly cleaned of all carbon, rust and metal shavings before a new plug is fitted or the element end can be damaged.

GOVONI UNIVERSAL GLOW PLUG REMOVAL KIT – GO470
This is a comprehensive kit for the complete removal of glow plugs stuck or broken at various points and includes an amazing, insulated magnet to assist with the removal of metal shavings as well as a heavily weighted slide hammer arrangement.

Depending on the style of glow plug you have to remove, or the location of the glow plug in the head, you can look at more specialised removal kits that are suited to your job. Call the team at Specialist Tools Australia and they can assist you with selecting the correct tools for your job.

GOVONI UNIVERSAL BROKEN GLOW PLUG ELECTRODE REMOVAL KIT – G311188000 OR SA-3752 GLOW PLUG TIP REMOVAL KIT
When extracting glow plugs, the glow plug tip (Electrode) may become seized in the electrode bore, and will often break at the point of the body and remain stuck in the cylinder head. The broken glow plug tips can be easily extracted with the help of this tool set which contains all of the tools needed to accurately tap resilient threads into the end of the glow plug.

Afterwards the glow plug tip will be extracted with the help of the extraction rod and a striking hammer. The drill will be guided precisely using the glow plug threading in the cylinder head. This will avoid any damage to the cylinder head. This set can be used with any current diesel motors using glow plug. thread sizes: M8x1, M9x1, M10x1 and M10x1.25, Govoni Universal Broken Glow Plug Electrode Removal Kit – G311188000 or SA-3752 Glow Plug Tip Removal Kit.

DUMMY INJECTOR AIR BLOWING ADAPTOR – GO509
This tool is used for blowing air into the cylinder during broken glow plug repair operations, used in conjunction with the broken glow plug repair and reaming tools. It is simply fit into the injector recess in the cylinder head and connected to the air supply, the air volume is adjusted via the tap as required.

GLOW PLUG RECESS CLEANING SET – G11109000
This is a universal reamer set with thread adaptors used to clean up the glow plug shaft area and the sealing seat in the cylinder head.

PROFESSIONAL COMPLETE GLOW PLUG AND SPARK PLUG THREAD REPAIR SET – G772004000
This kit is designed to repair/replace damaged glow plug or spark plug threads in the cylinder head using threaded insertsthat are fitted into the head using the included tap guides for correct alignment.

For more information contact Specialist Tools Australia on (02) 6280 4334, visit www.specialisttools.com.au or email [email protected]

Related Articles