With surprising regularity, we get questions about engine flushing services. Readers ask what an engine flush is; whether it will reduce engine wear; whether it is necessary and, if so, need it be done every 12,000 miles; whether oil changes aren’t adequate; and whether it is a moneymaking gimmick.
We don’t blame our readers for being wary. We congratulate them for seeking more information before agreeing and submitting their vehicles to a new procedure (kind of like getting a second opinion before surgery) and before forking over their dough. They cite prices ranging from $85 to $129 for the service.
For years, you also have heard the mechanic’s mantra to change your oil and filter regularly to keep your engine clean and trouble-free. So, why are some service advisers telling us oil and filter changes are insufficient?
Regular oil and filter changes will keep your engine clean, making flushing unnecessary. We have torn down engines with more than 100,000 miles that look shiny and clean inside.
We have torn down engines with less than 20,000 miles that needed dynamite to disassemble. It is, perhaps, these engines that may benefit from an engine flush.
In June 1999, Saturn published service bulletin 99-00-90-001 that states, “The use of internal engine cleaning equipment or the addition of any material to the engine other than engine oil is not necessary, recommended or endorsed. Saturn vehicle owners should continue to maintain their vehicles according to the maintenance schedules published in the Saturn owner’s handbook.”
However, you may be thinking about buying a used car, and you have no idea how well maintained it was. In that case, we don’t think it is a bad idea to have the engine flushed–to start out with a clean slate, as it were. Flushing may free up the rings or valves, but it may remove sludge that was acting to prevent leaks.
Even a manufacturer of the equipment warns that customers should be told that flushing may reveal problems that may require additional repairs.
Nevertheless, we consider engine flushing to be much like a colonic; it may help, but it probably won’t do any harm. Through the ages, people have used a variety of things to clean their engines’ innards. They have used kerosene, automatic transmission fluid, mineral oil and even commercial preparations designed for this purpose. Though these methods are cheaper than a professional flush, we do not recommend them. Using them runs the risk of severe engine damage.
Sure, engine flushing services are a way to make money–and that’s not a sin. The add-on sale has always been part of business in America, and it isn’t going to change. Who has not bought a suit and had the salesman suggest some shirts, a tie and maybe a belt? But you shouldn’t be a pushover for every suggested add-on service. You are free to choose.
In answer to the questions about the money, let’s let a dealer speak. A letter from one boasts: “We have … been averaging 100 flushes per month, for a total of $10,000 in profits per month.”
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Bob Weber is an ASE-certified Master Automobile Technician, having recertified every five years since 1978.
