This was one of the first "mods" I did when I bought my 2000 LS last year. I read about this and I decided to be proactive and not wait til there was a leak. It is a great $4 investment if you haven't done this yet.

 

In 13 yrs of having my Monte she has only leaked twice in the last 2 years. But If I get this part, would that mean I wouldn't have to get a new cowl?..(which we know is more $ then this fix). Thank you for this

 

As it turns out, the water leak was a result of changing the speaker in the door. The plastic carrier that holds the speaker has a rubber seal behind it. If you remove the carrier you have to insure when you reinstall it, it is tight. After beating my head against the wall, the light went on and I Permatexed the carrier to the door. No more leak. It was leaking from the carrier on the inside of the door to the carpet.

 

Had this leak when I was washing out the flood debris from the vents. Just ordered two, one for my 2003 Monte and one for my daughters 2001 Monte.

 

OMG I'm so glad I found this thread..my Monte leaked like a sieve the last time it rained and I assumed the windshield was to blame! I just ordered the part and coming in tomorrow!

 

Glad it helped!

 

I ran across this thread by shear dumb luck, and I'm so glad I did.
I was searching to see if I have a cabin air filter on my '01 and happened across this thread. Now I can take care of two problems at the same time.
For the record, I bought the car new, for my wife, and after her and two daughters racking up 197K miles, I finally get the car. That means the filter is original. It should look terrible. I have been lucky in that we have never had water in the floor.
also, my blower is only working on positions 2,3 and 4 so I'll be doing the resistor change as well.
I can't wait to feel the difference with a clean filter and high speed on the blower.
A big thank you to the OP!

 

Hope this helps you!

 

Thanks for the tip. Did this a few years ago on the '01 SS, and today on the '03 SS.

FYI- This part is actually standard equipment on '06 and '07 Monte's. Same part # and everything. Got mine on eBay for $3.50 with free shipping.

 

HI just found your post. very detailed and nicely done. I was an auto parts clerk for 30 years in the aftermarket and MB. OK i have a 2004 Monte Carlo SS, for the past 3 years. I noticed a load of water on passenger side floor ,after a soaker of a rainstorm. I have a feeling that this is not the first time this car had water inside it. Anyway i looked up the OEM part for GM 15794785 and it lists for 2006-7 montes only. My question, do you know if this part will fit on 2004 Monte windshield?