987 Boxster/Cayman Chattering wipers - how to fix.

It turned out to be rather simple actually. I ordered the correct wiper blades. The correct wipers have a 22" wiper on the port side (drivers side in US) and a 21" on the starboard side (passenger side in US.) They're available as a set from Bosch , PN: 582S "Twin Spoiler". About $25 for the pair from FCP (buy once and never again..) - SKU: BOS-3397001582 - FCP's listing. $23.19. (FCP including shipping is cheaper than Amazon Prime with "free" shipping.) And FCP guarantees whatever they sell for "life" - meaning this is the last pair of these blades you'll have to pay for. Whadda'deal.. Audi Porsche Windshield Wiper Blade Set - Bosch 3397001582 Audi Porsche Windshield Wiper Blade Set - Bosch 3397001582 www.fcpeuro.com It turns out the beam assembly (the part connecting to the arm) is shaped differently on the 21" blade - it raises the arm a bit higher and I suspect exerts more force toward the ends of the wiper blade. On that blade the framework has a slight convex curve to it making the center higher. On the 22" blade (which has an airfoil on it) the framework is basically straight. I've tried various brands from the local autoparts stores - Trico, Bosch solid-beam, Trico, Michelin and some Amazon sourced Chinese copies (probably actually the same blades) of the Bosch Aero-Beam. They ALL chattered. They ALL chattered even with a spotlessly clean windshield (cleaned with a dedicated windshield clay bar, followed by windshield cleaner and using the special "magic" windshield cleaning cloths I got suckered into buying. This was on a less than 2 year old OE windshield. The chattered wet, they chattered dry, anytime the wipers were running - they chattered. All of them sold in pairs were 22" for both wipers, and identical frame designs. The correct ones don't chatter. Wet/dry/drizzle.. just perfectly smooth wiping. No streaks. It's the little things like smeary/chattering wipers that can drive me absolutely nuts trying to solve and eventually turn me against the car when I can't solve it. Happily, I can now report it's solved. Get the right blades . I wonder what Porsche would sell me if I tried buying from them?

Like yourself, I’ve had trouble with aftermarket wiper blades. So when it came time to replace mine, I got Porsche ones from ECS Tuning. Interestingly enough, they were both 22” if I recall. And the passenger side had that curve while the drivers side had the spoiler thing. I haven’t had a chance to try them yet, but they seem to fit nicely. Perhaps next time I wash the car, I will test. Of course, with the Bosch ones working well and the FCP replacement program, those are almost a no brainer for next time. Windshield Wiper Blade Set Pair of 22" wiper blades www.ecstuning.com

I found that's what Porsche sells now. They used to sell two separate wiper blades, one 22" and flat, one 21" and curved - just like the Bosch set. They now sell a pair - most likely exactly what ECS is selling, with MSRP of around $49. I'd have to guess it's the two different types of blades that prevents the chatter. As you said - the FCP price and guarantee pretty much make it a no-brainer.

I just did this on the 987.2 last month @deilenberger - looking forward to seeing how it plays out. Only regret is not buying from FCPEuro...

I bought a set from FCP Euro with that AOS purchase. Relentless sun even with garaged vehicles surprised me in two ways: First, it kills all rubber, even though I stay at it with Griots and other products. Even the Ford eats wiper blades now. I'll never be "that driver" with a scratch track in the glass because "ah what's a little blade tear going to do"?. Many customers: "how do I fix that scratch"?, you don't you need to replace the glass now over a matter of cheap wiper blades you skipped out on. The bigger surprise? Turns out heat kills lead acid batteries dead with equal vigor to a week of below zero temps every year.

Bosch 22/21"

I'm curious how you tried to clean the windshield. The only ways I've found that work are the clay-bar and Bon-Ami Foaming Cleanser ("Hasn't Scratched Yet").. The Bon-Ami I'm a bit hesitant to suggest - but the original Bon-Ami was softer than glass and harder than munge deposited on the glass. The reason I'm hesitant to suggest it is someone always uses the wrong thing and then screams about scratching up their glass, SO.. I'll include the standard warning of "Test on an inconspicuous surface before using on visible glass.." I do know at least one person who claims there is no equal to it.. but I think I found one: Dedicated clay-bar. What you want is some clay used for surface contaminant removal from painted surfaces, but use this clay ONLY for windshields. Use it with a windshield cleaner as a lubricant (Windex or something similar.) You'll feel when it hits crud - the clay drags on the surface despite the layer of lubricant. Keep rubbing until it slides smoothly and effortlessly. That's clean glass. When done with the clay pack it away safely marked for WINDSHIELD ONLY, and give the glass a final clean with some windshield detergent and a clean microfiber cloth. IF you drop the clay on a dirty surface it's now garbage - throw it away. You'll end up scratching the windshield with embedded dirt particles in the clay. If the windshield isn't "this" clean - I'm not surprised it started to chatter after a bit. There can be a really hard buildup of road-crud deposits (and oil residue) on any car's windshield, and it's the deposits causing drag that results in the chatter. FOOTNOTE from a google: Bon Ami 1886 Original Formula Cleaning Powder is the original, “classic” formulation of feldspar and tallow soap. This product can be used on all of the same surfaces as Bon Ami Powder cleanser AND the 1886 formula can be used on glass, windows & mirrors and vintage auto windshields. And a rather fun thread on the subject: Bon Ami on Windshield??

Oh - one more thing that can be used: https://www.amazon.com/dp/B005HWBC5S/ref=cm_sw_em_r_mt_dp_78R4G36EM1F3RNH5T3BB?_encoding=UTF8&psc=1 Cerium Oxide - with a rotary polisher. It makes a mess so plan to wash the car after using it. It's a powder that is abrasive but softer than glass, so it can remove nasty deposits on the glass. And getting the glass really clean is the way to avoid chatter (besides the right wiper blades.)

I haven't done a true test of it, but I feel like using RainX (liquid) on a windshield has helped with chattering in my previous cars. The smoother glide on the glass seems to keep the blade from sticking, and hence chattering. I haven't done it on the Boxster yet (it's cold outside here in CT!) but I plan to do that when it warms up. Maybe I'll try it in the next few days - we're supposed to get into the 50s! I get some chattering now when the rain is light (misting to drizzle). If there is more rain, I don't... my theory is that the water is letting the blades glide better, hence they don't chatter... but if I set the wipers too fast, then there isn't enough water on the glass before the next sweep, and I get chatter... I've also had the best luck with the Bosch blades, generally speaking. I've had RainX blades, and that just seems like marketing and didn't help chattering issues when I tried them.

@schwinn - my experience with Rain-X on my windshield and wipers hasn't been favorable. It seemed to cause chatter and streaking. That was how I found out clay-bar works well to clean the windshield, it was the only thing that would take the Rain-X off. Rain-X makes the windshield hydrophobic - it rejects rain and it beads up. Ideally, on a really clean windshield, the rain should flow over it unbroken - hydrophilic. That doesn't seem to leave any streaking. Let us know how it works out for you.. I'd be interested if your experience is the same as mine.

this is a link to a previous discussion on wiper chatter... there are some products that can help... your milage may vary... 3 steps to solving wiper chatter/judder NOTE: try at your own risk! One of the first problems I had with my 987 was chattering wipers. they would start to skip/hop on the windscreen after just a few wiper swipes after applying the washing fluid and once the soap washed off, it started to chatter again. No amount of washing or glass... www.planet-9.com