Common problems associated with refurbished motors include hidden stress cracks, heat damage, overheating, oil line problems and fires. Some of these problems stem from errors during refurbishing, while others often occur during initial startup.
Stress and heat damage are most common on partially refurbished motors because they are often difficult to see. If left undetected, this type of hidden damage creates additional problems and sometimes ruins the engine.
Oil problems and startup fires usually occur during the initial startup of the refurbished engine. Priming the oil lines before starting the engine eliminates air bubbles and ensures reliable circulation of oil.
Fires are another potential problem during initial startup. Aiming a powerful fan at the radiator helps keep the engine cool during this process. Fire extinguishers quickly put out startup engine fires, but they create a large mess in the engine compartment. Most fires also respond to water from a hose, which leaves no mess behind.
Water is also an effective remedy for overheating. Newly refurbished motors have a higher average running temperature than other engines because the new components generate substantial friction. Friction levels generally normalize once the engine runs for about 20 minutes, provided that the oil lines have been primed.