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AV-SCANNER / Accessory guides / Engine and fuel
This guide gives you a complete, professional procedure for using a compression tester to run dry and wet compression tests on gasoline and diesel engines. It explains the tool's purpose, the types available, safe connection, step-by-step testing, and how to interpret the numbers with worked examples. You will learn to diagnose ring, valve, and head gasket faults, avoid common mistakes, and maintain and calibrate your tester. After reading, you will be able to perform a compression test confidently and decide when a professional diagnosis is required.
Guidance is general and covers many makes. Exact procedures and values vary by model, so confirm them in the factory service information for your vehicle.
Download all 12 sections as a branded PDF to use in the workshop.
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