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Clean Those Dirty Cam CoversPrintable version
Degree of DifficultyEasy
Estimated Time90 minutes
90 minutes
Open your hood and what do you see? If you’re like most car owners, the first thing you see is not the gleaming marvel of mechanical engineering you saw in the showroom all those years ago, but a greasy, dusty, filthy brown blob. You don’t dare touch it lest its grime infect you.

The “blob effect” is normal and nothing to be ashamed of. The engine room is a dirty place to live. It’s open to the elements and exposed to dust, moisture, and fluid spills and sprays. It takes only a year or two of all-season driving to turn even the most handsome new engine filthy.

What can be done about it? A coin-operated power wash is the easiest solution, but not the best one. Spraying water into the engine compartment under the high pressure found at typical coin-operated car washes can damage fragile components, force water into electrical connectors, and even contaminate the oil if it leaks past filler caps or dipsticks. If you want to hose down your engine, spray a mild household degreaser such as Formula 409, let it sit for a few minutes, set the nozzle on your garden hose to create a gentle mist, and use that to wash off the cleaning fluid. Then run the engine so the heat evaporates the water out of crevices where rust would otherwise form.

Still not happy with the way it looks? Here’s a job that will make your motor sparkle, give you some peace of mind as to the engine’s condition, and provide you with a fascinating glimpse into its inner workings. And it requires relatively little time and money. Veteran shade-tree mechanics will have done this job many times, but for novices, it can be a relatively risk-free and rewarding way to get to know your motor and make it shine.

Cams, Rockers, and Rollers
Many new cars have a plastic cover on top of the engine. This cover blocks sound and neatens up the engine compartment. If this applies to you, removing the cam/rocker covers to shine them up may be pointless, as the acoustic cover hides everything. If there is no acoustic cover, or you want to take off the cam/rocker covers anyway, then read on.

On the very top of the cylinder head is a sort of oblong dome secured to the cylinder head by a significant number of small bolts or screws. If your engine is an inline-4 or inline-6, there will be one dome. If the engine is a vee-configuration, such as a V-6 or V-8, there will be two of these domes, or one capping each cylinder bank. This component can be made of stamped steel, cast aluminum, or plastic, and it goes by many names: cam cover, rocker cover, rocker-arm cover, rocker box, and valve cover. These names are often used interchangeably, but each name actually refers to a specific engine type.

Example: “Cam covers” are found on overhead-cam engines, because the cover is actually covering the cam shaft and its cam lobes. “Rocker arm cover” refers to an overhead valve pushrod engine such as the new Chrysler Hemi or the venerable Chevrolet small-block V-8. In these engines, the camshaft is deep in the block but the rocker arms, set in motion by the pushrods, sit on top of the cylinder head and lift the valves. From now on, we’ll refer to these domes as cam/rocker covers.

The inside of a cam/rocker cover is a hot, oily place. As the engine runs, oil is fed under pressure to the moving components to keep them lubricated, and then slung by those components in every direction, draining back to the engine’s oil sump via holes in the cylinder head. Some good reasons to remove the cam/rocker cover, besides making it look pretty: if you have oil weeping from the cover-to-head seal, or if you have just purchased the car and don’t know its maintenance history.
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