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Diagnostic equipment gets to the root of the problem

Every once in a while, my 2008 Subaru Impreza won't start. The engine will turn over, but will not start. I wait a minute or two and everything is fine. It is well past warranty and the problem is intermittent so I am reluctant to take it back to the dealership because of its hourly rate and the fact it might have to spend considerable time tracing the problem. Any ideas? – Stuart

The facts are that an engine requires fuel and a spark, so one of those must be the problem.

Of course, today's engines are much more complex so finding the problem may be a chore, but will come down to one of those two.

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Another possible source if both spark and fuel are present is a lack of compression but you can rule that out as the engine runs normally at times.

The bad news is that to find the problem you have to do so at the time of the failure. If the engine starts most of the time, it would be difficult to locate the issue. The good news is that the engine control module has probably noticed the problem and stored a code that the dealer's diagnostic equipment (the expensive one operated by a highly trained and well-paid technician) could likely display immediately, allowing that technician to go directly to the problem.

Car wax

I just bought a new car, a Kia Optima, and want to keep it a long time. I believe in cleaning my cars regularly and that protecting the paint with a coat of wax will reap benefits at trade-in time. All the various wax manufacturers make claims as to how long their product will last. What is the truth? How long will a good wax or paint sealant last? – Nigel

A man after my own heart! But that's like asking how long your shirt will stay clean or how long you can leave food uncovered before it goes bad. The answer is – it depends on a variety of things.

What is the atmosphere where you live and park? Is there a manufacturing or other facility nearby that emits harmful byproducts that might eat away at the wax? Do you use a drive-through car wash? Does it have brushes or is it brushless? Does it use recycled or fresh water? Most use a fairly strong soap that will remove wax almost instantly. When you wash the car yourself, do you use dish detergent or a softer soap meant specifically for car washes, one that will not take off the wax?

To simplify, anything corrosive or abrasive enough to physically damage a modern, factory clear coat finish will also damage the microscopic layer of protection contained in a coat of wax.

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As an avid car cleaner, you will realize that unless you are using a pure wax you cannot get more than one coat on. Most waxes contain a cleaning component that will remove any wax remaining on the surface.

As a rule, I plan on six months of protection for a vehicle that is regularly kept in a garage. After a thorough cleaning, I make it a habit to use a clay bar to remove any surface contaminants, then a couple of coats of wax containing a lot of carnauba and no cleaning agents – World's Best Wax and Xymol are two that come to mind.

In addition to parking inside when not in use, I try to park under some kind of cover whenever possible away from the sun's rays, but not under a tree that can drop nasty stuff onto the paint. Keep the vehicle clean so nothing can attack or form a harmful relationship with the surface. The rest of the time, I depend on a hand-applied layer of protection, which I consider to be a sacrificial barrier that slows down the effect of elements that will harm the paint.

Find something you like and use it often. I have spent years trying different products and am constantly on the lookout for something new. But it comes down to a regular application of a protective layer.

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