I have a 2002 monte carlo and seem to have a problem with water. My front passenger side floor mat and carpet has a puddle not even a understatement a puddle and what wondering is it just my ac someone leaking water in but it doesn't make sense since I don't remember using my ac and I have had the car only maybe a month. If anyone knows what it is please I need help asap

 

This could be a leaking heater core if the the liquid is slippery to the touch, but the most common problem due to inherent design flaw is the cowl-water deflector under the cowl that allows rain water to pass through the cabin air filter and heater blower and onto the passenger side floor. Fortunately, it's a cheap easy fix.
Here's a link to the correction: https://montecarloforum.com/forum/fw...lem-fix-26663/.

Here's the part: Chevrolet GM OEM 06-07 Monte Carlo Cowl-Water Deflector 15794785 | eBay

Chevrolet GM OEM 06-07 Monte Carlo Cowl-Water Deflector 15794785 | eBay

 

Well i have a grand prix as well could i take the piece off of 02 grand prix and put it on my monte carlo?

 

The new part is an updated version to channel the water away from the cabin fresh air opening. the actual leak comes from the rubber gasket underneath.....after years it gets dry and allows water to pass ..... I reakon you could change that rubber piece until the new part comes...however idk if its the same on the grand prix? ive heard of folks running a bead of silicone along the top lip of that rubber strip , but the new part is a better permanent option.

 

I don't believe the deflector pieces was offered on the Grand Prix until '04, the Impala and Montes until '06. But you can take apart the cowl on the Grand Prix and see if it is there (maybe someone else did the mod). I ended up doing this water deflector mod on my Monte and ex-wife's Impala. Both cars had the original rubber deflector come off and fall under the cowl, making it useless.

Once you open the cowl on the Monte, it should be easy to tell instantly if this is the fix you need (the rubber piece is dry rotted, missing or not properly placed). The updated deflector was about $4 from the dealer when I did it. Completely worth knowing the problem is solved.

 

Your Grand Prix and Monte Carlo are both W bodies and used the same part between 2000 and 2004 (05?), so unless the GP already has the fix applied you will end up with the same problem. If you don't want to wait for shipping, the dealer sells them for about $5. I think they sell them so cheap because they know it's their mistake, but don't want to issue a recall. 5th gen's and 7th gen's actually use the same part, so you know they realized the design flaw on 6th gen's and went back to what works.

 

I was having the same issues with water on the passenger floor of my 04 Dale Jr SS. I have found and fixed the problem. Look at the weather stripping when you open the door. I was looking mine over and noticed you could see the breather holes in the weather stripping facing out towards the door itself. These holes are supposed to be in the stripping so that it can compress when the door shuts. I'm not sure if this is a bad batch of seals that everyone has gotten, or if the person that has the job of installing these on the line just sucks. For a temporary fix I cut out approximately 1 inch of the seal right down near the bottom of the door where its making its turn to run along the bottom of the door. this gives the water an outlet and it will dump outside of the car and not come in. I have been dry as a bone inside and we have had some very heavy rain this month. I didn't notice any extra wind noise after doing this either. I also had an issue with the drains on both of my doors getting clogged up , I would hear the sloshing in the doors, I took a drill bit and hogged out the holes a little and the problem has been solved. Good luck to anyone that need help.