My husband washes under the hood of our car with a garden hose. Bad idea?

Dear Car Talk

Dear Car Talk | Aug 01, 2003

Dear Tom and Ray:

My husband is one of the smartest people I know. He can also be one of the biggest knuckleheads, if given the chance. When my husband is done washing the car, he will then open the hood and run the garden hose (for a very long time) in and all around the car's engine. Basically, he washes the engine. He says it removes the dirt and salt. I say it will rust the engine and get water in places it doesn't belong. I could maybe understand the salt thing when we lived up North. But now we live in Florida, 13 miles from the ocean. So my questions are: 1) Should anyone be washing the engine? And 2) Does salt air need to be washed off your engine? -- Terry

TOM: You know, Terry, when I read the first two lines of your letter (about your husband being smart and a knucklehead), I thought it was from my wife, because she often says the exact same thing about me.

RAY: Except she leaves out the "smart" part.

TOM: The answers to your two questions are: no, and no. Unless you're trying to find the source of an oil leak, there's really no need to wash your engine. Ever. And there are two significant downsides to it. One is that all of the toxic grease and oil that comes off the engine washes right down your driveway and into the public sewer system or leaches into your water supply. So, think about that the next time you brush your teeth.

RAY: And if that doesn't bother you, there are a number of very expensive pieces of electronic equipment under the hood that can get ruined if they get exposed to excessive amounts of water -- the most expensive being the car's computer. And that costs many hundreds of dollars.

TOM: So we recommend to our customers that they just let the outside of the engine get dirty. That's why car makers invented the latched hood -- so you can close it.

RAY: And if you feel an obsessive need to have a clean engine, even though no one can see it, go to a car wash that does steam cleaning. First of all, they'll have a grease trap, so they can properly dispose of all the gunk that comes off your car. And second, because they've probably had to pay for half a dozen replacement computers already, they should have a pretty good idea of what parts to avoid.

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