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Porsche 993: How to Repair Foggy Headlights

Headlights will fog and yellow over time. This how-to will show you how to clean them right up.

By Jared Hammond - April 2, 2015
Contributors: stronbl

This article applies to the Porsche 993 (1993-1998).

The headlights in the Porsche 993 are made from polycarbonate. They have great impact resistance and won't shatter easily, but they are vulnerable to being pitted with road debris and yellowing from sunlight. Eventually, a fog will develop that could cause problems in your ability to see at night if it's not dealt with. The solution is quite simple and easy to follow. This guide will show you how to repair them.

Materials Needed

  • Drill with buffing attachment
  • Shop towel
  • Flat head screwdriver
  • 1500 & 3000-grit sandpaper
  • Rubbing compound
  • Helmsman spar varnish
  • Mineral spirits
  • Glass cleaner
  • Cloth

Step 1 – Remove the headlight bulb

Some owners have had issues where they've generated static electricity while polishing. This static can damage the trunk module which could be a costly repair. To be safe, disconnect the car battery's negative terminal and then disconnect the headlight. Reach behind the headlight and twist off the bulb.

Figure 1. This headlight needs to be cleaned.

Step 2 – Sand the headlight lens

Spray some water on the headlight lens and sand it down with the 1500 to 3000-grit sandpaper. Cover the edges around the headlight in tape, then apply a rubbing compound. Buff it in with your buffing attachment at the lowest setting.

Figure 2. Sand and buff the headlight lens.

Step 3 – Apply polish mixture

For the final polish, create a mixture that's one-half Helmsman Spar Varnish and one-half Mineral Spirits. Use your shop towel to brush the mixture slowly and evenly across the headlight lens. The mixture will dry clear and the varnish will give it UV protection that prevents yellowing for up to two years. Wait 24 hours for the polish to properly dry.

Figure 3. Polished headlight.

Pro Tip

There are plenty of different kinds of polish that can be used. The two mentioned just happen to help with the yellowing problem. Acrylic enamel also works but will need to be sanded after it dries. For an all-in-one package, use a headlight restoration kit.

Step 4 – Clean the inside of the headlight lens (optional)

In most cases, cleaning the outside of the lens should be enough. But sometimes dirt and debris will get on the inside of the lens and on the reflectors. To get in there you'll have to remove the lens. There are five catches around the headlight that hold it to the car body. Pry these open, then use a flat head screwdriver to separate the lens from the body. When you have the lens removed, clean the metal reflectors with glass cleaner. Then, give the lens interior the same treatment you gave to the exterior, sand and rubbing compound then polish. When that's finished, reconnect the headlight lens and catches.

(Related Article: Porsche 993: How to Replace Your Headlights - Rennlist.com)

Figure 4. Headlight lens removed.

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