engine flushing

[Oliver S.]

Hello,

what are the opinions about flushing an engine in general and in particular for older Corvettes while changing the oil? Does this make sense for cars that are only driven a few hundred or at most a few thousand kilometers a year or is engine flushing a waste of money or is there a potential danger? Shops that offer flushing claim that this will help to maintain and extend the life of an engine. Thanks in advance.

Oliver Schoenhaar
#33229

[Joe L.]

Re: engine flushing

Oliver------

Would I, personally, have my engine "flushed"? Under absolutely NO circumstances that I could envision!

[Duke W.]

Re: engine flushing

"Flushing" the engine oil, transmission, and "fuel injector cleaning" are examples of services that are not needed on any car that reasonably well maintained. Thes services are not recommended as a regular maintenance practice by any OEM that I am aware of.

For a collector car that is driven a few hundred to a few thousand miles a years, an annual oil and filter change is good maintenance.

Where collector car owners fall down on maintenance is the cooling system and brake system. The cooling system should be completely drained at both the radiator and two block drains and flushed with a garden hose by removing the heater hose from the inlet manifold to flush the heater core circuit and reverse flush the engine. This should be done every two years REGARDLESS OF MILEAGE because the clock runs continously on coolant while it's in the engine. - even if it's rarely driven.

The same applies to the brake system. Every two years REGARDLESS OF MILEAGE, the m/c reservoir should be siphoned out, fresh fluid installed and then you should go around the car three or four times with 6-12 bleed cycles per corner until about a quart of fluid is flushed through. This will ensure that the old fluid is purged. Conventional glycol brake fluid absorbs moisture and corrodes the system, which is usually why calipers and master cylinders fail.

It's too bad the commercial service industry does not promote useful services such as cooling system and brake system flushes instead of virtually useless services such as engine oil flushes, which add to their bottom line, but don't give the customer much if anything for their money.

If you store or don't drive your car in winter, change the oil and filter just before storage. The clock does NOT run on fresh oil in the crankcase during storage as long as the car is not subjected to condensing humidity .i.e. it's stored inside.

Duke

[James G.]

Re: engine flushing

Well said Duke. And it works.

I had for 16 years a V-12 Jaguar XJS. It's V-12 all alluminum engine and brake system never gave a bit of problem as I flushed 4 gallons of coolant every 24 months and flushed brakes as you stated.

That Jag had over 110000 miles when I sold it in Oct 2000 and the dealer always commended me on how it keeps running due to good coolant services.