Glow Plug Testers for Diesel Engines

Frequently Asked Questions About Glow Plug Testers

Glow plugs assist in the cold start of diesel engines and can contribute to starting problems if they are defective. The following questions explain how to test glow plugs, which glow plugs can be tested with the GKP 05, and what the difference is between an electrical test and the mechanical removal of a glow plug.

• What is a glow plug tester?

  A glow plug tester is used to check the condition of glow plugs or glow pins in diesel engines.

  The GKP 05 uses an LED display to indicate whether the glow pin being tested is functioning properly or is defective.

  The device is part of the Test and Diagnostic Equipment for Automotive Electrical Systems category.

• Is it possible to test glow plugs without removing them?

  Yes. That is precisely one of the key advantages of the GKP 05.
  
  The test is performed with the glow plug installed. It is not necessary to remove the glow plug to perform a functional test with the device.
  
  This reduces the amount of work required and allows for an initial diagnosis before deciding whether to remove the glow plug.

• Which glow plugs can be tested with the GKP 05?

  The GKP 05 is designed for glow plugs with the following voltages:

  • 4.4 V
  • 5 V
  • 12 V

  Leitenberger specifically lists rod-type glow plugs, ceramic glow plugs, and glow plugs from ISS quick-start systems as suitable applications.

• Can 4.4-V glow plugs be tested with the GKP 05?

  Yes. The GKP 05 is specifically designed for 4.4-V glow plugs.
  
  It can also be used to test corresponding modern low-voltage glow plug systems, provided the glow plug is intended for the specified application.

• Can 5-V glow plugs be tested?

  Yes. 5-V glow plugs are also within the intended scope of use for the GKP 05.

• Can standard 12-volt glow plugs be tested?

  Yes. The GKP 05 is also suitable for 12-V glow plugs.
  
  This means the tester covers different generations of glow plugs and diesel engine applications.

• Can ceramic glow plugs be tested using the GKP 05?

  Yes. Leitenberger specifically lists ceramic glow plugs as the appropriate type for the GKP 05.
  
  However, the voltage range and the specific application must fall within the device's specifications.

• Can rod-type glow plugs be tested with the tester?

  Yes. Rod-type glow plugs are also among the explicitly listed applications for the GKP 05.
  
  Rod-type glow plugs are a common type of glow plug used in diesel engines.

• Can the glow plugs in an ISS quick-start system be tested?

  Yes. According to Leitenberger, the GKP 05 is also suitable for glow plugs from ISS – Instant Start System.

  The device thus supports not only traditional glow plugs but also corresponding quick-start systems.

• How does the GKP 05 indicate a faulty glow plug?

  The test result is indicated by two LEDs.

  The device features, among other things, the following indicators:

  “Glow plug OK” and “Glow plug defective”.

  It also displays the device’s operating status and a low battery warning.

• How do you connect the glow plug tester?

  The connection to the glow plug and ground is made using sturdy test leads with clamps.
  
  The exact procedure must be followed in accordance with the tester’s operating instructions and in compliance with the respective engine or vehicle manufacturer’s specifications.

• Does the GKP 05 require the vehicle battery for power?

  No. The GKP 05 has its own power supply via a 9-V block battery.
  
  The tester also features a low-battery indicator and an automatic shut-off function.

• Can you also test glow plugs with a multimeter?

  Depending on the type of glow plug and the manufacturer’s specifications, electrical measurements using a suitable multimeter may be part of the glow plug diagnostic process.

  For example, resistance measurements can be used for this purpose.

  A specialized glow plug tester, such as the GKP 05, on the other hand, is specifically designed for the rapid evaluation of suitable glow plugs and displays the result directly as “OK” or “defective.”

  You can find suitable measuring instruments under Automotive Multimeters, Current Clamps, and Electrical Measuring Instruments.

• What is the difference between a glow plug tester and a multimeter?

  A multimeter is a universal electrical measuring instrument that provides specific readings such as voltage or resistance.
  
  A glow plug tester, on the other hand, is specifically designed to test glow plugs.
  
  The GKP 05 displays the test result directly as “Glow plug OK” or “Glow plug defective” without requiring the glow plug to be removed.

• Can the glow plug tester also be used on commercial vehicles?

  Yes. Leitenberger explicitly lists commercial vehicles, in addition to passenger cars, as an area of application for the GKP 05.
  
  It is crucial that the glow plug being tested falls within the tester’s specifications in terms of design, voltage, and application.

• Can the GKP 05 also be used in industrial diesel engines?

  Yes. Industrial diesel engines are also explicitly included among the listed areas of application.
  
  This means that the test device is not limited exclusively to passenger car diesel engines.

• Is a glow plug tester the same thing as a glow plug extractor?

  No. These tools serve completely different purposes.

  A glow plug tester is used for the electrical or functional testing of a glow plug.

  A glow plug removal or extraction tool, on the other hand, is used for the mechanical removal of a seized glow plug.

  You can find suitable removal tools under Glow Plug Removal and Extraction Tools for Diesel Engines.

• What should you do if a glow plug is detected as defective and is stuck?

  A glow plug that has been identified as defective must be removed properly when replacement is necessary.

  There is a risk of damage during removal, especially with glow plugs that are seized or caked with carbon deposits.

  For such applications, Leitenberger offers special glow plug removal and extraction tools for diesel engines in various wrench sizes.

• Can the glow plug tester determine why a glow plug has failed?

  The GKP 05 is used to determine whether the tested glow plug is functional or defective.
  
  It does not automatically identify the exact cause of a defect.
  
  In the event of repeated glow plug failures, a more thorough diagnosis of the preheating system and the associated electrical components may therefore be necessary.

• Is a faulty glow plug always the cause of starting problems in a diesel engine?

  No.

  Defective glow plugs can contribute to starting problems, especially at low temperatures, but they are only one of several possible causes.

  Depending on the symptoms, other factors such as the starter battery, starter motor, fuel supply, fuel injection system, or the mechanical condition of the engine may also play a role.

  To test the starter battery and the starting system, tools such as automotive battery testers and test equipment for battery and charging systems are available.