Cabin Filter & Water Deflector
The W-body Grand Prix's are known for having "water on the passenger floor". This is caused by water running down the windshield,
under the cowl, down through the blower motor and onto the floor. GM had a fix that consisted of a piece of rubber seal that was
supposed to deflect water away from the blower motor. I had this set up and never experienced any water leaks, but many others
weren't so lucky. Being that I wanted to install a cabin filter, I figured that I would kill two birds with one stone and install the proper
fix for the water problem. The fix is from GM, #15794785; a large plastic water deflector that is cheap and easy to install. This part
comes on the '04+ Grand Prix's, but fits perfectly on the '97-03 models as well. As for the cabin filter, the Grand Prix's never came
with them, but the provision is there, so all you have to do is put a filter in place. Here is how it goes.....
July 2011
Fram #CF8392Acabin filter.
GM #15794785 water deflector.
Wipers in the up position.
Pull back the rubber seal, then remove the three fasteners that hold down the cowl cover.
Remove the cowl cover, then remove the original rubber "deflector" (if you have one).
Clean up any leaves, pine needle's or other debris.
Install the new cabin filter.
Install the new water deflector.
You need to remove the lip on the underside of the cowl cover. I also cleaned up the debris trapped in the intake grille.
Trimmed and cleaned.
Cowl cover back in place.
The left over parts.
I got my info and knowledge on this "mod" from GrandPrixForums.net:
Water In Floorboard (take 2) - The Permanent Fix
June 28/2014
Been almost three years (currently @ 300,009 km), so time to change the cabin filter.
Top of filter: new on the left, old on the right.
Bottom of filter: new on the left, old on the right.
Old filter; top, top, bottom.
August 26/2017
Been three years, so time for some fresh air......
If you have any comments, suggestions, or see any errors, please let me know..... cbradley@telus.net
Last updated on June 28/2014
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