Piston Slap: On the Edge From Poor Headlight Aim?

Sajeev Mehta
by Sajeev Mehta
piston slap on the edge from poor headlight aim

Chris writes:

Hi Sajeev,

Love the column, it’s one of the things that keeps me coming to TTAC daily. I recently purchased a 2017 Ford Edge SEL AWD with the 2.0-liter Ecoboost. I love it so far but there is one glaring issue. The projector beam halogen headlights are simply awful, I can’t believe they left the factory this way. What are my options? Brighter Halogen bulbs, LED Bulbs or an aftermarket HID kit?

Help! I’m almost totally in the dark here!

Sajeev rambles:

Almost totally in the dark with Ford headlights? I remember that feeling, thanks to the tiny low beams with peeling chrome projectors on my 1995 Lincoln Mark VIII: useless after five-plus years of heat cycling. Luckily there was a factory HID upgrade (which I sorta wrote the book on)…

…and luckily for you there’s a man named Daniel Stern.

Daniel Stern actually answers:

The problem isn’t just in your head; take a look at how the 2017 Edge did in the IIHS headlamp tests. Don’t just skim, really spend some time studying the results for the optional HID and standard halogen lamps. They both got a poor rating, but for different reasons: the halogens gave inadequate seeing distance (and created some glare), while the HIDs gave excellent seeing distance — much more than what is considered optimal — but created a lot of glare.

It’s a little counterintuitive, but lamp aim — not bulb type or lamp technology — is by far the main thing that determines how well you can (or can’t) see at night. One thing about those IIHS headlamp ratings is that they don’t check or adjust the aim before testing.

They reason that most vehicle buyers never have their headlamp aim checked, and that’s correct, but it means the IIHS headlamp grades are a composite of how good or bad the lamps are, and how good or bad the aim is on the particular vehicle they test. Take a look at this analysis by one of America’s top vehicle lighting researchers. It’s dense and science-y, but the takeaway is that fully half the headlamps that got a “Marginal” or “Poor” grade would have got “Acceptable” or “Good” if they were aimed correctly.

So first, go find a dealer or shop that has and properly uses an optical headlamp aiming machine and see to it (babysit them as necessary) that the lamps are aimed carefully and correctly. Shining the lights on a wall is a very distant second preference; it really can’t get them closer than maybe the same state where the ballpark is located. Worse, many shops, and even dealers, just randomly crank the lamps up if the complaint is “I can’t see” or down if it’s “I get flashed.”

Read up on this here and see this informative VW bulletin on how to aim headlamps correctly. There are different brands of optical aiming machine, but they all work very similarly, and the same process is used on Fords, VWs, and every other brand of car; no other method is good enough. Most Fords have the VOR type of headlamp, though some have VOL, so whoever is doing the aim job needs to carefully check the headlamp lens markings and set the aiming machine accordingly.

After that’s done, think about the bulbs themselves. Two ideas (“LED bulbs” and “HID kits”) have to be taken out behind the barn and shot right offhand, because halogen lamps need to use halogen bulbs or they don’t, can’t, won’t work effectively, safely, or legally and can do extensive (and expensive) damage to the vehicle. See here for a lengthy dissertation on the how and why. The particulars are different for LED vs. HID, but the principles and problems are the same overall.

However, all halogen bulbs are not equal. Automakers put in long-life bulbs as original equipment, because Americans have this weird thing where they think the car’s a piece of junk if a consumable part needs to be replaced and the maker doesn’t give them a new one under warranty. (Amen to that. – SM)

But long-life bulbs put out dimmer, browner light and give poorer beam focus — that’s the tradeoff for the longer life. You can easily and inexpensively replace the long-life/low-luminance bulbs with high-luminance bulbs of the correct type to get brighter light and longer, wider beam coverage without endangering your car, your safety, or your warranty, but you have to shop carefully because the market’s full of bulbs claiming to be an upgrade when they’re actually a downgrade. A bulb promoted primarily with claims of producing “whiter” light, with blue tint on the whole surface of the glass, is a red flag; the blue-tinted glass blocks a significant amount of light that would reach the road without the tint. One major maker-marketer of that kind of bulb got swatted pretty hard some years ago for it, but there’s still a bunch of these blue-glass “whiter light” bulbs on the market.

The low beams on your car take an H11 bulb, and right now the best-performing H11 is this one from GE. Disregard the not-really-fraudulent-but-not-really-what-it-sounds-like use of the word “Xenon”; that’s a minor sin worth putting up with for this bulb’s better performance. It’s a certified, type-approved H11, so it’s legal and safe to use — nice to know in general, and it also means you can’t (by law!) be denied warranty coverage because of nonstandard bulbs. But do note the lifespan will be considerably shorter; you might have to change them in a year or even less, which is considered normal in Europe and Asia but can be a bit of a shock to Americans.

So try that first: a careful aim job and the best available bulbs. If the headlamps still aren’t good enough for your needs and wants, the only legitimate next step up is a big but costly one: swap in a set of the factory-optional HID headlamp assemblies. They look very similar to your present lamps, but despite common misunderstanding, the projectors they contain have completely different optics versus your halogen projectors; it’s NOT just a different bulb holder. Think of it like two pairs of the same kind of eyeglasses: they look alike, but yours have to have different lenses than mine if we’re both to be able to see.

The HID headlamps give a much wider, longer-reaching beam. They’ll be expensive from a dealership, but if you want to leave not even a tiny thread for future warranty claim denials to tug at, taking the car to the dealership and saying, “Install the factory optional HID headlamps” will achieve that.

The other option is to find a like-new perfect set of used ones via www.hollanderparts.com or www.car-part.com . Still genuine factory parts, much less expensive, and with friendly smiles from you and your dealer service writer you might still get ’em installed by a Ford technician. Note that the vehicle’s body computer may have to be flashed to recognize and correctly operate the HID lamps, and they’ll have to be aimed carefully as described above.

[Image: Ford]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Join the conversation
2 of 63 comments
  • Chris Chris on Jan 30, 2018

    OP Here! Thanks for the excellent info Sajeev and thanks everyone else for the thoughtful discussion. I'm going to start by asking the dealer to check the aim when I'm next in for service. If that doesn't help I'll be ordering a set of GE Nighthawks. Looks like a pretty simple job to change the bulbs.

  • 28-Cars-Later 28-Cars-Later on Jan 30, 2018

    Excellent piece Mr. Stern. I do wonder though, how difficult is it to service the light bulbs on this model?

  • 3SpeedAutomatic Drove a rental Cherokee for several days at the beginning of this year. Since the inventory of rental cars is still low, this was a 2020 model with 48k miles and V6. Ran fine, no gremlins, graphics display was easy to work, plenty of power, & very comfortable. Someone must of disarmed the lane assistance feature for the steering wheel never shook (YES!!!!!!!!). However, this woman's voice kept nagging me about the speed limit (what's new!?!?!?!).I was impressed enough to consider this a prime candidate to replace my 11 yr old Ford Escape. Might get a good deal with the close out of the model. Time will tell. 🚗🚗🚗
  • Bullnuke One wonders if this poor woman entered the US through Roxham Road...
  • Johnds Years ago I pulled over a vehicle from either Manitoba or Ontario in North Dakota for speeding. The license plates and drivers license did not come up on my dispatchers computer. The only option was to call their government. Being that it was 2 am, that wasn’t possible so they were given a warning.
  • BEPLA My own theory/question on the Mark VI:Had Lincoln used the longer sedan wheelbase on the coupe - by leaning the windshield back and pushing the dashboard & steering wheel rearward a bit - not built a sedan - and engineered the car for frameless side windows (those framed windows are clunky, look cheap, and add too many vertical lines in comparison to the previous Marks) - Would the VI have remained an attractive, aspirational object of desire?
  • VoGhost Another ICEbox? Pass. Where are you going to fill your oil addiction when all the gas stations disappear for lack of demand? I want a pickup that I can actually use for a few decades.