Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Old headlights

I am wondering if it is a good idea to replace the glass on the headlights of a car when the car gets old? I ask this because the glass gets dirty and cloudy as the car ages. You can clean the headlights but it does not last that long and seems to get just as bad pretty quickly. What do most people on this great site do? do you keep cleaning the glass, or do you replace it at a certain age of the car?

If you have glass it isn’t necessary. However, the tungsten filament will slowly vaporize and deposit residue on the inside of the bulb in addition to becoming itself dimmer and more sensitive to failing. So even with glass bulbs, if the lights are old it might be a good idea to change them.

How old IS your car anyway? My impression from your comments is that you have polycarbonate lenses like most of us, but without knowing the year, make, and model that’s just a guess.

You mean plastic, right? Lots of discussions here on cleaning headlights, some methods seem to work pretty well, last a while.

I think this is a 1997 Thunderbird that the OP has in another thread. That said the last time I was at the Nissan dealer for service they had a display of before and after plastic lenses they had polished for a reasonable price. Much better than the ones I had done.

If it IS a '97 T-bird it’ll be polymer.

Replace them , you’ll be glad you did.
There is NO calculatable. . ‘‘age’’ . for replacement since wear factors vary so differently.
But since they’re now so bad as to make you ask ?
You just answered you own question.
You can get aftermarket lamps at many places other that the dealer ( $158 ea O’Reilly / $177 ea AutoZone ). . . AND , if it is the 97 t-bird mentioned , Ford no longer sells those anyway.

Lenses can be easily and inexpensively polished.
The bulbs only should be replaced.
But we still don’t know what kind of car it is.

Remember after polishing the lenses with the 3M (or equivalent) kit, you need to wax them with a good car wax (I use Meguiars Gold Class). This will help keep them from getting yellow again. Be sure to re-wax them every time you wax the car … Which should be at least twice a year if you don’t already wax it.

Also, for next time, keeping them waxed from the time you buy it can help prevent this from happening in the first place. My Acura has over 100,000 miles on it and the headlights are still crystal clear, even though I see Acuras the same age as mine running around with yellowed, scratched headlights. But I wax the things at least every time I hand-wash the car.

it is a 97 thunderbird with almost 180,000 miles on it.

See the discussion in this thread:

So get a polishing kit and polish them. Or pay $250 a set for new ones.
I agree with shadow’s recommendation to wax them after.

My Riviera had glass lenses so when they got sandblasted there was nothing that could be done. Replacements not readily available either but did happen to find a decent pair in a junk yard after a deer incident. Yeah if plastic polish but if glass replace. But the one thing to look at in addition is the condition of the inside reflectors. When they break down, it can be as bad as cloudy lenses.

I’ve never had glass ones long enough to get compromised by road grit. Unfortunately, I have had a few windshields that long.

Deterioration of the filaments is usually the cause of a need to replace the sealed beam headlights long before erosion is. Either total failure or loss of output… now how DO those lumens get out? :smiley:

As I’ve said before, polycarbonate lenses can be sanded and clearcoated by a body shop. I had mine done for $50 each and, two years later, they still look like brand new lenses. It is cheaper than new lenses and more durable then any other wax or coating.

Rockauto has new headlamp assemblies for the OP’s car starting at $71, though the $113 Dorman brand may fit a bit better.