Location of water leak? - Z06Vette.com - Corvette Z06 Forum
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 12-07-2004, 04:25 PM Thread Starter
Z06 Authority
Join Date: Sep 2003
Location: South Bay, SoCal Fest III, IV, V, WinterFest I, II, & III
Posts: 1,750
Location of water leak?

I'm wondering if anybody has isolated where they had water leaks on their car. I had previously ignored a "minor" leak that I had, into the driver-side footwell, after washing the car, due to the fact that I pretty much flood the car with water and thought that the windshield area drainage was being overwhelmed.

We've had some pretty steady rain (for SoCal) lately that seems to cause the same leakage. Obviously, I park outside. My concern is that it appears to have overflowed my rubber mat and dampened the carpet all the way back to behind the driver's seat (I park on an inclined driveway)--leading to concerns about mildew. Sheesh! As if smelly A/C ducts weren't enough!

I was wondering if there tends to be a common area of leakage that I could look for, or where you all may have found leaks. When it dries up I intend to seal the windshield with silicone sealant, and wondered if there was anyplace to pay particular attention to.

One of my concerns was from when the dealer did an A/C cleaning, about a year ago. From what I have read, one of the things they do is drill a hole into an A/C duct so that they can spray it with a disinfectant (Ozium and some sort of foaming cleaner), after which they seal the hole with a dab of silicone. If they didn't seal the hole, and its in the wrong spot--well, leaks into the car could be possible. I don't have any clue of where they drilled into, or if there is a general spot the techs normally would do this at. BTW, the mildew stench at start-up is back. I also need to see if the other fix they have--installing a fan timer that allows the fan to dry out the coils--also pertains to the '03 Z's; the bulletin I saw only went up to the '02's.

Thanks for any input any of you may have! (besides put it in the garage :P )

Yellow car with 4 tires and a lugnut behind the wheel.
NCM #26915
S-TEE is offline  
Sponsored Links
post #2 of 9 (permalink) Old 12-08-2004, 04:14 PM
Z06 Master
Join Date: Sep 2002
Location: Malibu Calif.
Posts: 3,166
Hi Scott,

Sorry to hear you are having leakage problems. I haven't experienced any leakage problems with my car that I can share with ya, but being a builder, I do have some experience fixing water leaks. I think your first idea that the windshield drainage is suspect is a good one. Any seam, penetration, gromet, fitting, etc should be suspect. Try water testing starting at the low point and work up from there. Remove the windshield wipers and hood cowl and begin testing the pan area around the bottom of the windshield. If you find that the windshield seal is the problem, make sure you use recommended sealant. Mixing various types of sealants can sometimes cause problems and failures just by being in contact with one another.
Good Luck in your hunt!


01 QS/Blk, A&A LS2 402 stroker w/ Vortech T-trim 749rwhp 722rwtq, RPM Tranny.
Zrod is offline  
post #3 of 9 (permalink) Old 12-08-2004, 08:02 PM
Z06 Addict
Join Date: Nov 2002
Location: springfield MO
Posts: 247
I`ve had 2 main leakage problems. One was the rubber seal on the drivers side windshield. Leaked pretty bad when driving and when water was sprayed on it. Two was abitch to find took the dealer 4 weeks to isolate and fix. Way to long if you ask me. This was a leak that showed up after a long soaking rain. It was caused by a bad body to 'A' pillar joint. All covered under warranty. Good luck with yours!
perry is offline  
post #4 of 9 (permalink) Old 12-08-2004, 09:13 PM
Junior Member
Join Date: Feb 2004
Location: Philadelphia PA
Posts: 2
Location of water leak

Here is the location of your water leak, had the same leak in my car. Remove the wipers, cowl ,and wiper motor you wil see the seam right underneath the motor, I reccomend getting some crest brushable seam sealer at a local body supply shop.

This is a service VME involving 1997-2003 Corvettes.

Corvette (Y- Body) 1997-2003 Water Leak Into the Drivers Footwell Area

There have been several instances of a water leak into the drivers footwell. The typical comment from the owner may be that their left foot is getting wet. One possible source of the water is a cowl seam located under the windshield wiper motor. There have been instances of a void in the bonding material used to assemble the cowl panels. Repairs will consist of removing the wiper motor and resealing the cowl seam.

2003 Black 2003 Z06
18/19 Chrome Z06 wheels, Halltech Stinger, Corsa, LG Long tubes.
Certified GM Tech
backnblackz06 is offline  
post #5 of 9 (permalink) Old 12-08-2004, 09:48 PM Thread Starter
Z06 Authority
Join Date: Sep 2003
Location: South Bay, SoCal Fest III, IV, V, WinterFest I, II, & III
Posts: 1,750
Thanks for the replies! The wiper motor area leak is not one that I would have suspected. I planned on sealing the perimeter of the windshield with silicone sealant, and may now have to investigate that area also. I'll likely seal the rear window, as well, as I notice water at the seam of the sill and rear mouldings when I wash the car.

My main concern is I'm limited on the dry, daylight hours that I can work on the car, and I need to fix the problem before mildew becomes a problem... :(

Yellow car with 4 tires and a lugnut behind the wheel.
NCM #26915
S-TEE is offline  
post #6 of 9 (permalink) Old 12-08-2004, 09:54 PM
Junior Member
Join Date: Feb 2004
Location: Philadelphia PA
Posts: 2
Hardtop Water Leak into the Rear Compartment Area

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

The customer may complain of water in the rear compartment area behind the seats or even under the seats. Water may be dripping from either ends of the garnish molding under the rear window. The actual entry point is the seam where the rear edge of the hardtop is sealed to the body tub flange.

The possible leak paths can be better understood using the following SI documents:

# 842633 "Roof Description"
# 844927 "Hardtop Replacement Procedure"
# 657292 "Quarter Panel Replacement - Rear Hardtop" Step 22 quarter cutaway illustration.
The rear window garnish molding (SI Document Number 656014) and the rear compartment front side trim panels (SI Document Number 656914) should be removed (if this has not already been done). This will reveal the entire "seam" where the hardtop meets the tub as well as the "cups" referenced below.

The following are 2 likely leak path descriptions/corrections.

Water entering anywhere along the seam where the hardtop ditch (or U - channel) meets the tub flange. The assembly plant runs bead of butyl sealer across the hard top ditch (or U - channel) before it is set down onto the tub flange. This sealer bead is approximately 25.4 mm (1 inch) forward of the SMC structural adhesive bead (on rear top flange) that contacts the tub shelf . It runs across the back (below the rear glass) and wraps onto each quarter panel. A void in this sealer will also allow water to enter the vehicle, but should be easily seen from inside the passenger compartment with the garnish molding removed (per above). Any voids must be resealed using urethane sealer. As an added measure when addressing larger voids, urethane can be applied and then thumb grade (clay type material) used on top to push the urethane further into the void.
Water dripping from the holes in the bottom of the 2 "cup" structures. The hardtop is made of 2 SMC (Sheet Molded Compound) panels bonded together. Reference the quarter section cutaway in step 22 of SI Document Number 657292. The 2 SMC panels are bonded slightly inward of the actual hardtop edge formed by the panels. At this outer edge, there is a small gap that runs the full length of the edge (cross car, forward of rubber deck lid seal). This edge is virtually impossible to see, especially where it runs forward of the deck lid seal. A small mirror can be used at the outer most rear edges (with the deck lid open) to obtain some view of the gap. If the run channel is filled to the point of overflowing, water will pass through this gap and find any voids that may be present in the SMC panel bond. If a void is present, water will enter and work its way to the lowest point in the hard top structure which may be one or both cups referenced above. Although the gap across the vehicle (forward of decklid) differs slightly from the quarter panel area (illustration referenced above), the leak potential is the same. Remove the rubber trunk seal (for some clearance) and apply urethane sealer as neatly as possible to the underside of the hardtop rear edge. If this does not correct the leak, the quarter panels will have to be removed (SI Document Number 657292), and the gap in that area sealed as well. Any excess sealer should be wiped away using an alcohol dampened rag.

2003 Black 2003 Z06
18/19 Chrome Z06 wheels, Halltech Stinger, Corsa, LG Long tubes.
Certified GM Tech
backnblackz06 is offline  
post #7 of 9 (permalink) Old 12-10-2004, 05:29 AM
Z06 Addict
Join Date: Aug 2002
Location: SC
Posts: 106
Water leak in drivers side floor.

My 2002 Z06 had a water leak in the area of the drivers side front floor. After driving in the rain or washing the Z06 the carpet would be wet. I found when I washed it and drove up my steep driveway to the street water would drop onto my clutch foot. A rubber grommet in front of my clutch pedal in the firewall was half in and half out. You could have someone take a flashlight into the engine compartment and shine it at the firewall and if you got down low inside the car on the drivers side you could see light comming through the firewall at the loose grommet. It was an easy fix of reseating the grommet.

dennis is offline  
post #8 of 9 (permalink) Old 12-14-2004, 01:11 AM Thread Starter
Z06 Authority
Join Date: Sep 2003
Location: South Bay, SoCal Fest III, IV, V, WinterFest I, II, & III
Posts: 1,750
Thanks for all the replies!

I spent this past Saturday sealing the front and rear windows on both the window and body-side of the trim moldings. Compared to older cars with chrome trim, it is more difficult to do the post-sealing clean-up, as the silicone tends to stick better to the rubber molding and running a razor blade on the rubber trim can easily carve out large chunks. I also sealed the gap between the door trim and the roof--seeing as how this may have served as a drip rail, the jury is still out as to whether this was a good idea.

Thanks to backnblackz06's tip, I removed my wiper cowling and took a look by my wiper motor. Yup, there seemed to be a gap in the bond along the foward seam and also down in the wiper motor well. I was able to seal both areas using silicone sealer and with the help of a small, disposable "flux" brush, which I used to force the silicone into the seam cracks. After allowing the silicone to cure overnight, I trimmed excess from the windows then proceeded to flood the car for a leak test. So far it looks like the leak is fixed!

Another thing I did, to help the wiper motor well to drain, is to flip half of the drain tube's flaps open. To best describe this, picture a condom-- --if the tip had a large X sliced in it, that would be like what the bottom of the drain tube is like. You can flip half of that X inside-out, so there is absolutely no restriction to water drainage from the tube, especially if a large volume of water is trying to drain.

I also ran a bead of silicone under the front and rear edges of the interior door trim to help seal and form a raised barrier to water intrusion from water getting past the door seams--if water can get in the door area by the door sills, it is easy for it to flow under the sill and edge trim and get into the carpeted area. Hopefully this works--I still have to test this part of the sealing more. I had noticed that I would get a lot of water dripping from the seam between the door sill trim and the piece behind it, leading me to speculate that water was getting under the trim piece at the top rear of the door and flowing down.

Hope this will help some of you do an at-home fix, too. I know I was dreading having to take the car in to the dealer--even if it was covered under warranty.

Yellow car with 4 tires and a lugnut behind the wheel.
NCM #26915
S-TEE is offline  
post #9 of 9 (permalink) Old 12-14-2004, 10:21 AM
Z06 Member
Join Date: Sep 2004
Location: Redondo Beach
Posts: 52
Hey Scott,

Sorry to hear about your problems. See, that's why I don't wash my car . Just kidding. For what it's worth, I took my car down to Showcase Chevrolet in Westminster for the lower control arm nut/washer recall, and they didn't butcher my car. If you have to go to a dealer, you might try them. Oh well. Good luck, and hope you got things fixed!
crznZ06 is offline  
Sponsored Links

  Z06Vette.com - Corvette Z06 Forum > C5 Z06 Specific Topics > C5 Z06 - Pit Road

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
Water Leak mannyz06 C5 Z06 - Grandstand 3 10-03-2006 06:38 AM
Diff leak-but not in the typical location! vortech C5 Z06 - Pit Road 0 08-24-2006 07:20 AM
Water Leak Yellow Streak C5 Z06 - Grandstand 5 06-17-2004 04:58 PM
Water leak 99Hardtop C5 Z06 - Pit Road 11 03-22-2004 09:49 AM
Water leak fixed! Cave Man C5 Z06 - Grandstand 0 12-28-2002 02:45 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome