lightonthehill

THIS IS A PROPOSED STICKY FOR MOD APPROVAL

****RESEARCHING 6TH GEN MAXIMA POWER SUNROOF LEAKS*****


Nissan's Power Sunroof Philosophy:

Nissan knows all power sunroofs will eventually leak. Rather than waste time trying to make the sunroof impervious to leaks, or trying to delay the onset of such leaks, Nissan approaches the problem by having a system in place to safely dispose of the leakage.

In view of this, we must recognize that our 6th gen sunroofs do not 'leak'. If water is getting into the passenger cabin through the power sunroof, what we have is a DRAINAGE problem.

Symptoms of a power sunroof drainage problem would include water dripping from the ceiling near the front of either door and/or around/near the ceiling storage box for eyeglasses. My first indication of a leak was a pool of water in the driver's footwell.

How Things Work:

If one opens the sunroof and looks closely at the installation, it is possible to see a drainage system underneath the edges of the sunroof opening.

Any water that leaks in follows the plastic troughs until it reaches one of the two front corners of the unit. Looking deep into those dark corners reveals two small drain holes in each corner; one hole faces the opposite side of the car, and the other faces the rear of the car.

Checking For Problems:

To check the sunroof for drainage problems, use a syringe (or similar device) and, with the sunroof fully open, put water into one of the front corners near either drain hole. The drain holes are only an inch apart, and immediately converge into one drain tube.

As the water accumulates, it should flow into the holes, down through a drain tube, and come out just behind the front tire. If the water in the corner reaches a depth that covers a drain hole, but does not begin draining out within minutes, there is a blockage in the drain tube.

Repeat this test at the other front corner. The drain tubes on both sides of the car must work; if the car happens to be parked with the side with a blocked drain tube lower than the side with a good drain tube, the water can't reach the good tube. That happened to me.

Finding The Blockage:

To narrow down where a drain tube blockage may be, one can take something like a stiff plastic weed trimmer string (thicknesses between .065mm and .095mm worked well for me), round off the end (to facilitate sliding it through a tube), and, on the side with the blockage, run it down the hole that faces the opposite side of the car (because running it down the hole that faces the rear would require an immediate sharp turn).

Work the string carefull, but firmly. I am able to run it around five feet down an unblocked drain tube. If the string refuses to go down nearly that far, it is probably hitting the blockage. Measure the length of the string you were able to get in the tube; that tells you how far down the blockage probably is, and is useful info for the service tech.

Probable Cause:

About forty inches down, the tube passes a bracket near the firewall about even with the level of the bottom of the windshield. If not installed carefully, that bracket will crimp the drain tube. My dealer has seen only two such cases out of over 200 6th gen Maximas he has sold.

Fix:

This is a warranty fix. It only took my dealer an hour or so to fix.

Important Caveat:

Two months after my driver's footwell was soaked, I finally removed several pieces of trimwork and lifted the carpet. The two inch thick padding underneath was totally waterlogged. It took me two weeks of airing and blowdrying to get it completely dry.