The rubber on the blade must fold side to side depending on which way it is moving across the windshield. If it does not, it will result in chattering and all kinds of other noises. The easiest way to detect if they are folding properly is to turn off the key in the middle of the swipe and see if the rubber edge of the blade is folded to the correct side. Porsche actually had a special tool to adjust wiper are angle back in the day. It was a plastic cylinder with a slot that could be slipped over the arm to bend it so that the blade would sit squarely on the windshield and thus fold side to side depending on direction of travel. The same thing can be accomplished with a pair of duck billed pliers and a rag (to prevent scratching the arm). Even new blades will make noise if not adjusted properly. Hope this isn't TMI.--Dave

I had an Acura MDX for 10 years and for many of those battled a line that wouldn't clear forming with a variety of aftermarket blades. After a few months, it was like a clockwork. I spoke to the dealer service manager during a recall visit and he said "I know this sounds like a dealer sales job but the Acura blades are actually much better and put more uniform pressure on the glass". Bought some, he was right, never had the issue again.

No doubt the brand of blades makes a big difference. The way the rubber is held in place can make a huge difference.

Several things I know to cause this: Any after market windshield - while some are better than others they are not finished, polished and made to the same standards as any OE glass. So the actual surface is rougher which makes even good blades skip.

Dirt......................Best way to clean is to use a non-abrasive such as Bon-Ami. Using this with warm water, terry cloth and patience will lift the crap out of the pores of the glass. Do this every 2-3 times a year is the way to go.

OEM wiper blades. Stay away from the multi-edge crap and other marketing tricks.

Valeo Frameless ULTIMATE All-Season OE Replacement Wiper Blade .... cheaper on Amazon

http://forums.pelicanparts.com/uploa...1452270495.jpg

I buy new wiper blades.