Diagnosing engine mechanical problems can be performed with normal shop equipment.
Compression testing with a good quality gauge will reveal condition of the engine rings, pistons, cylinder bores, valves, and guides.
Vacuum diaphragm operation is quickly tested with a hand operated vacuum pump. These pumps are available from companies such as Kent-Moore, Snap-On, RobinAire and Lisle.
A digital or analog multimeter is used for many tasks such as checking wire continuity, shorted-open circuits and components, ground connections, battery condition, glow plug current levels, and so on.
A tachometer is required for checking/setting idle speeds. On diesel engines, an especially accurate tachometer is needed to check cranking speeds of 100-180 rpm.
An oil pressure gauge is necessary in order to accurately test engine oil pressure. The best gauges are mineral oil filled to avoid indicator needle bounce. The gauge should have a dial range up to 100 psi in 2 psi increments. Necessary adapters to connect the gauge are available from either the gauge manufacturer, or Kent-Moore Tool Corp.
An all purpose dial indicator set such as JÐ8001, is also needed. Accurate measurement of clearances, component wear, chain deflection, and overhaul dimensional settings is only possible with a dial indicator. A good quality vernier caliper and micrometer set are also needed to check part tolerances.