If oil is changed on schedule, you shouldn't have to flush the engine." There may be a few instances where an engine flush is required, but be aware that engine technology has progressed to the point that many newer vehicles not only don't need and engine flush, they may be harmed by the procedure.
An engine flush runs solvents through the vehicle's engine, ostensibly in order to break up sludge that builds up over time as an engine runs. "But car-makers say, pieces of that broken up sediment can clog up other parts of the engine and ruin it," according to the KNBC report
A good engine flush can help loosen deposits and dissolve sludge, returning your engine to like-new condition. However, in old engines with high miles, sludge may be the only barrier keeping oil from seeping through worn or cracked seals.
An engine flush is an aftermarket additive engineered to flush accumulated deposits, sludge, and other gunk out of your engine. You simply pour it into your engine's oil-filler port and let your engine idle for roughly 10-15
When you remove the buildup your engine will run more efficiently and just plain perform better. Many quick lube type places will claim that you need to flush your engine every 5,000 to 10,000 miles. This is not true. Many modern engines can go 35,000 before needing a flush.