Many options for clean plastic panels
Dear Mike: My SUV has black plastic cladding on the sides and wheel wells, and no matter how many times I run it through the carwash it just gets grayer and more blotchy. How can I clean this area up, as it’s really unsightly? — T.G, Williams, Ariz.
A: That gray stuff is composed of hard-water minerals, road film and wax built up on the surface of the molded plastic panels. If the plastic is black or gray, it’s black (or gray) all the way through. Beware if the plastic is the color of the body, silver or champagne, because that’s painted over the base color of the plastic, and the advice I’m going to give may not work — and may damage any paint. Treat painted areas like the rest of the car’s finish.
Start by washing the area by hand with any commercial car-washing product as per the directions on the bottle. Use a moderately soft bristle brush to scrub any accumulated material out of the cladding’s texture. Don’t scratch the paint nearby. If the cladding is still blotchy when dry, try a soft cloth and straight, undiluted white vinegar. This should dissolve any minerals left behind on the surface. Rinse well.
Still blotchy? Maybe it’s waxy build-up. Try a cleaner intended for vinyl surfaces, bug and tar remover or lacquer thinner on a soft cloth. Avoid getting lacquer thinner on any painted surfaces — if your car has a lacquer-based paint, the thinner will remove it.
To prevent the problem from recurring, use a vinyl protectant before waxing the rest of the car. If none of this works, your last resort is convertible top dressing, which actually has black dye in it like shoe polish. This should cover up almost anything.
Do not use shoe polish, which has a wax base that can’t take the temperatures that a car body sees on sunny days. It will leave black smudges all over anything within several feet of the car, especially your wife’s white slacks.
Dear Mike: In 1984 I had my 1969 Corvette engine rebuilt, but I never got it back into the car. Now I’d like to. Can I just pour some Marvel Mystery Oil in the crankcase and start it up, or is there something else I should do? — M.S., via Internet
A: As wonderful as Marvel Mystery Oil is for keeping your air tools from gumming up, it’s not nearly good enough for this. Do yourself a big favor: Disassemble this engine and rebuild it. There are plenty of things that could be wrong, starting with the dust and insects that may have worked their way into your engine over the years.
Also, I’ll bet that the cylinder walls, camshafts, lifters and valve seats are covered in a light coat of rust. Some of the valves are open, and their valve springs may be sacked out. The gaskets have been compressed and dry for years, and may leak when the engine is run.
It’s possible to “pickle” an engine for this kind of long-term storage. It involves covering most machined surfaces with fogging oil or Cosmoline, and hermetically sealing it in plastic to keep moisture and dirt away. If this was not done, you’re asking for trouble unless it’s taken apart and attended to properly. Some surfaces may need machining if the humidity was high where the engine was stored.
Dear Mike: Water keeps collecting in one of the headlights on my 1999 Chevy. Not just a few drops, but an inch or more. And then the headlight lamp blows. The dealer dries it out, replaces the bulb for $25, and sends me on my way. The dealer has suggested replacing the whole headlight assembly, but it’s over $250. — T.B., Bozeman, Mont.
A: A certain amount of condensation inside the assembly is normal. But enough water to splash up and crack the bulb is far too much.
These assemblies are normally vented in some fashion, either with a vent fitting or by means of one or more hoses that lead to a dry place in the front of the car. One of two things is amiss: The vent isn’t venting, or there’s a leak somewhere that’s admitting too much moisture.
Check for a bad gasket or boot over the bulb socket. You should also look at the seam between the lens and the reflector. It’s filled with a hard sealant — be sure there are no pinholes or cracks. In fact, it may be necessary to remove the lamp assembly to inspect the whole business for cracks.
Lighting experts I talked to at Osram Sylvania suggested immersing the lamp in a bucket of water and looking for bubbles escaping to pinpoint any leaks. Then you should check the venting system as well. Look for kinked or pinched vent hoses, vents that are blocked by insects or errant undercoating or even mud.
If you do find a crack or leaking seam, my experts don’t recommend patching it. I disagree. I’d fix a small pinhole with epoxy or low-volatility silicone sealant. If you use more than a Chiclets-size amount of epoxy or sealant, it’s probably too much. If the lens itself is cracked or has holes in it, it’s time to get a new assembly.