The flushing of a car’s automatic transmission fluid is a procedure that has been performed for decades. Most dealerships and independent oil-change shops offer it along with other maintenance procedures. It’s an especially good thing to do when a car gets 100K+ miles on it because it flushes out the normal dirt and debris that has collected over the years. Transmission flushes typically cost some $80 to $120 but you only have to do it do it once or twice during a car’s lifetime.
If transmissions are flushed, then why aren’t engine blocks flushed? After all, engine oil gets really dirty. Well, they are now. Many service repair shops now offer through engine block flushes. The theory behind it is sound. During ordinary use, debris and gunk build up in an engine, particularly in vehicles that haven’t had their oil changed often. By forcing a cleaning solution thru an engine’s oil system under pressure, the debris can be loosened up and flushed out.
How it’s done
Engine flushing isn’t a complicated procedure. First, the engine is warmed up and the old oil is drained out. Then a special cleaning agent is added to the engine in place of the old oil. This cleaning solution isn’t just added to the engine filler spout though. It is forced thru the oil channels by a special machine. When the flushing is finished, the clean solution is then out and fresh oil is then added and topped off. Usually a new oil filter is installed at the same time.
When does an engine need its oil flushed?
Most older engines can benefit from having an oil flush, particularly cars with unknown maintenance records. You just never know if the previous owner waited a long time in between oil changes. Sometimes you can even see the effects of this by looking in the oil filler cap. If you peer in there and see lots of oily sludge, it’s time for a flush. And if you buy an older car, why take a chance; get your engine flushed out just for piece-of-mind.
Another situation that you might want to consider flushing is a car with recent internal engine work. After you have any major internal engine work done, such as a complete engine rebuild, you may to get the engine oil flushed. This will remove any small metal particles and grit that is left over from machining work. Particularly that which has collected in the oil channels.
When you shouldn’t flush
Ready for this? Engine oil flushing is not always recommended. In fact, some manufacturers advise against performing it on their vehicles regardless of the car’s mileage. The service department at Holden Dodge of Dover, a local Chrysler, Dodge, Jeep, Ram dealer in Dover, DE warns car owners to be careful. Honda, for example, is not a fan of oil flushing. Their belief is that by performing regular oil changes with the proper oil, engine flushes aren’t necessary. The engineers at GM suggest the same. They state in their manuals that “Engine oil flushes are not recommended. If oil is changed on schedule, you shouldn’t have to flush the engine.” Heed the warning because an oil flush could void the warranty on your car too.
When in doubt, check with your local brand dealer and ask them. Chances are that they perform engine oil flushes and will know what to suggest.