1990 to 1995 Diesel OM602 and OM603 Prechamber Removal Threaded Fitting

Dec 7, 2018


Welcome to Grafco Electric's comprehensive guide on the removal of threaded fitting prechambers for 1990 to 1995 Diesel OM602 and OM603 engines. In this guide, we provide detailed information, step-by-step instructions, and essential tips to help you successfully complete the prechamber removal process.

Understanding Prechambers

Before diving into the removal process, it's essential to understand the role and significance of prechambers in diesel engines. Prechambers are crucial components that aid in efficient combustion by promoting fuel atomization, improving ignition, and reducing emissions. For 1990 to 1995 Diesel OM602 and OM603 engines, the prechambers feature threaded fittings that require removal for maintenance or replacement purposes.

Tools and Materials

Ensure you have the following tools and materials ready before starting the prechamber removal process:

  • Socket set with various sizes (specific to your engine model)
  • Torque wrench
  • Ratchet handle
  • Combustion chamber cleaner
  • Rubber mallet
  • Thread sealant
  • Protective gloves
  • Safety goggles

Step-by-Step Instructions

Step 1: Preparation

Before working on the engine, ensure it is cool to avoid potential burns. Additionally, disconnect the battery to prevent any electrical mishaps. Safety should always be prioritized during any maintenance procedure.

Step 2: Accessing the Prechambers

Locate the prechambers on your 1990 to 1995 Diesel OM602 or OM603 engine. They are typically found on the cylinder head, adjacent to the injectors. Once located, carefully remove any components obstructing access to the prechambers, such as air filters or intake manifolds.

Step 3: Loosening the Prechamber

Using the appropriate sized socket, gently loosen the threaded fitting prechamber. Ensure you apply steady force, avoiding excessive pressure that could damage the prechamber. If the prechamber seems stuck, lightly tap it with a rubber mallet to free it from any corrosion or buildup.

Step 4: Removing the Prechamber

Once the threaded fitting prechamber is sufficiently loosened, carefully unscrew it from the cylinder head. Take note of any sealing materials or gaskets that may need replacement during reassembly. You can remove the prechamber by hand or use a ratchet handle for added leverage.

Step 5: Cleaning and Inspection

With the prechamber removed, thoroughly clean it using a combustion chamber cleaner to remove carbon deposits or any foreign substances. Simultaneously, inspect the prechamber for any signs of damage or wear. Depending on the condition, you may need to replace the prechamber entirely.

Step 6: Reinstalling the Prechamber

Before reinstalling the prechamber, apply a thin layer of thread sealant to ensure a proper seal and prevent any potential leaks. Screw the prechamber back into the cylinder head, ensuring it is securely tightened. Be cautious of over-tightening, as it can cause damage.

Step 7: Final Checks and Reassembly

After reinstalling the prechamber, double-check that all components are securely in place. Ensure the torque specifications are followed during reassembly to prevent any issues. Reinstall any previously removed parts, such as air filters or intake manifolds, and reconnect the battery.


Congratulations! You have successfully completed the prechamber removal procedure for 1990 to 1995 Diesel OM602 and OM603 engines. Regular maintenance of prechambers is vital for optimal engine performance and longevity. Following the detailed steps outlined in this guide ensures the process is conducted safely and effectively. Should you need any further assistance or have additional questions, feel free to reach out to our team at Grafco Electric.

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Matthew Swanson
Thanks for sharing this guide! Removing prechambers can be tricky, so having step-by-step instructions and tips is super helpful. Can't wait to give it a try on my Diesel OM602 engine.
Nov 12, 2023
Ray Lego
Great guide for prechamber removal!
Nov 8, 2023