I have heard that Engine oil flushing is a necessary part of engine maintenance. Is this so?
NO! At best engine oil flushing does nothing but lighten the consumers wallet. At worse flushing the engine with a flushing machine thins out the oil which causes accelerated engine wear. Remember that the flushing machine flushes out the oil but does not get all the flush out, which is left behind, and that flush does not provide lubrication when you start up the engine again. It takes a bit of time to get the oil pump going.
So at the very worse it can cause engine wear, and even chunks of sludge can become dislodged and plug up the oil filter. Typically flushing increases engine wear and does not do anything for the sludge, because the sludge is above where the flushing material is and does not get even touched as the flushing solution moves through the engine.
