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I found the leak this morning after only 15 minutes of driving with the a/c on.
It's at the bottom of that blob of silicone seal. Right above the lip before the floor. It was pooling there. You could see it coming out.
I showed up at dealer and showed them. I have to dry it all out before they will try to seal it.
a/c drain leak location
Interesting, I wonder what they are going to do about that.
Other posts have suggested that there is nothing on the other side the tube where it enters the tunnel to direct water out of the tunnel. Your post suggests that there is a way for water to get from the inside of the tunnel to the car's interior.
^^^
Yep. I agree. Thought for sure there was either a hose or small metal or plastic channel on the other end of that fitting that would take condensate water outside the bottom heavy aluminum cover. Can't very well seal the structural bottom plate that uses strong bolts to form the bottom of the box.
Wonder why there is silicone in one area? It it possible there is a small channel inside the center tunnel that takes water from that hose and fitting and brings it to the bottom. Would think if so, there would be a a small hole in the bottom plate BUT I can't see any on my car under that area. The mystery continues. Perhaps when the dealer finds the solution to Cratchet's water leak we'll know more.
It looks like some of that spray Flex Seal could be used on that area after all that silicone is scraped off...allow the Flex Seal to cure, then apply silicone again..
That product is like liquid rubber.
I hope ALL the cars at the factory get sealed properly. This issue is a real pain...
I found the leak this morning after only 15 minutes of driving with the a/c on.
It's at the bottom of that blob of silicone seal. Right above the lip before the floor. It was pooling there. You could see it coming out.
I showed up at dealer and showed them. I have to dry it all out before they will try to seal it.
a/c drain leak location
That is where mine was pooling at also but mine was definitely dripping from where the grommet goes into the tunnel right above that. I could clearly see water dripping down the side of the tunnel and pooling there.
Good catch. Allowing the water to just run down the side of the tunnel wall, water will find a path and once established it will tend to follow that path. Seems like it would be a good idea to just have a portion of tube on the opposite side of the pass-thru grommet to carry the drain closer to the bottom of the vehicle.
A little silicon sealant in that area should do the trick. Looks like you just earned yourself a TSB-T Shirt.
This is one of those cases where video of this occurring would be mighty helpful to those trying to figure it out. I'd be highly suspect of any low-point being the point of infiltration.
OP: Post some pictures of the water, soaked towels, etc. and show them to your service manager.
Good catch. Allowing the water to just run down the side of the tunnel wall, water will find a path and once established it will tend to follow that path. Seems like it would be a good idea to just have a portion of tube on the opposite side of the pass-thru grommet to carry the drain closer to the bottom of the vehicle.
A little silicon sealant in that area should do the trick. Looks like you just earned yourself a TSB-T Shirt.
My thought is similar. Just appears to be a poor design to me. I'll explain:
I have two air conditions in the house with the air handlers and evaporators in a large section of the 2nd floor that is an attic. The condensate goes from a pan where the evaporator is located in a 3/4 inch PVC pipe in a 20 and 30 foot run over joists and insulation out the 2nd floor wall to the ground. Both sit on large metal pans (just in case) that have a float switch that shuts the units off if the pipe gets clogged! Can watch them drip condensate on the ground! The outside pipes are housed (for ethics) in a U shape anodized aluminum channel..
Would seam to me that that C8 AC condensate should go from that visible fitting on the outside of the tunnel into a small U channel or pipe inside that sticks out of the bottom cover perhaps a 1/4 inch. Just allowing the water to go wherever it want's in that large tunnel with many pipes doesn't look like the right design? Just my thought.
My thought is similar. Just appears to be a poor design to me. I'll explain:
I have two air conditions in the house with the air handlers and evaporators in a large section of the 2nd floor that is an attic. The condensate goes from a pan where the evaporator is located in a 3/4 inch PVC pipe in a 20 and 30 foot run over joists and insulation out the 2nd floor wall to the ground. Both sit on large metal pans (just in case) that have a float switch that shuts the units off if the pipe gets clogged! Can watch them drip condensate on the ground! The outside pipes are housed (for ethics) in a U shape anodized aluminum channel..
Would seam to me that that C8 AC condensate should go from that visible fitting on the outside of the tunnel into a small U channel or pipe inside that sticks out of the bottom cover perhaps a 1/4 inch. Just allowing the water to go wherever it want's in that large tunnel with many pipes doesn't look like the right design? Just my thought.
Yeah, I agree and was somewhat shocked to hear they just left the water to run down the side of the center tunnel. If that vertical side of that tunnel went all the way down to the lowest point of the car, it wouldn't be an issue (other than aesthetics). They have a lot of sealant where it actually connects though, and it is obvious that water can enter there. Don't plan to drive my C8 in deep water, but wonder if just water from the road becomes an issue?
I stopped by my dealer's part department today and we looked at the drawings for the evaporator drain and tube as shown in the pictures above.
The schematic confirmed that there was NO hose on the other side of the tunnel wall that connected to the evaporator drain line.
So it in fact just flows out of the tube and fitting and down the side of the tunnel to make it's way to the ground.
Just another FYI.
This is one of those cases where video of this occurring would be mighty helpful to those trying to figure it out. I'd be highly suspect of any low-point being the point of infiltration.
OP: Post some pictures of the water, soaked towels, etc. and show them to your service manager.
In the pit of my stomach I think your right about the low point NOT being the point of infiltration.
The service guys saw my soaked micro fiber towel when I stopped by. They had 2 guys in there looking at it.
I'm now supposed to "dry it all out" and they will "seal it" on Monday.
I'll let them do that but will insist they keep it and drive it around for 20 minutes with 2 of their guys inside looking for any leak.
I had my car in the shop Thursday because of wet carpet on the passenger side. The mechanic said he ran the AC for two hours and didn't see the fitting going into the tunnel leaking. He thought maybe floor was wet from rain getting in. Thoughts?
^^^
If you read through the posts in this and another Thread on the subject you'll see that:
Condensate water comes from a pan under the AC Evaporator through a hose to a fitting on the interior of the center structural tunnel.
Some report the hose connection at the plastic fitting was leaking and just needed to be attached better to the barb.
The hose connection at the evaporator pan was found to be a source of a leak in one case.
Several were told the fitting needed replacement (not sure what the defect was as it appears to just be attached with sealant.)
It's been validated that the condensate water just goes from that fitting and runs down the center tunnel interior wall.
The bottom of the tunnel is a thick aluminum plate that is secured with ~30 strong bolts as it makes a structural box chassis support.
The water appears to have no defined exit. Apparently it's expected to: 1) perhaps evaporate as there are engine coolant metal pipes flowing ~180 F water in the tunnel 2) drop out somewhere but there is no visible opening near where that interior tunnel fitting in located.
A poster showed his leak is on the interior bottom of the tunnel below where the plastic fitting is located. It appears to be leaking at what is failed sealant at the interior bottom of the tunnel. So it probably ran down and did not drip out of the bottom aluminum plate junction where you would think it would drip (or from a bolt in that area where one poster said the condensate water was seen dripping.)
No feedback from anyone who has seen the bottom aluminum plate removed with all the ~30 bolts taken out to see what the junction looks like between the tunnel and the center tunnel channel to define why condensate water would leak back into the car interior and require sealant at the bottom inside of the tunnel.
Bottom Line: Still questions as to where this condensate water goes and is supposed to go!
I had my car in the shop Thursday because of wet carpet on the passenger side. The mechanic said he ran the AC for two hours and didn't see the fitting going into the tunnel leaking. He thought maybe floor was wet from rain getting in. Thoughts?
Take the line off the pass-thru fitting, attach a longer line to funnel, pour a bunch of water through it. Not too fast though, because it needs to run down the inside wall and not shoot across the tunnel. See if you get water coming through the lower seal area.
One would think that if the dealership had a Class "A" Corvette certified mechanic, that he would do all of the Forum mentioned tests. I would hazard a guess that some of the mechanics assigned by dealers to the C8 WET floors situation is not one of the dealership's Certified "A" mechanics. As a customer, i would inquire and .....
^^^^
Appears to me GM "Value Engineered" (a phrase from back-in-the-day) where you looked at every nut, bolt, bracket, line etc and eliminated or combined functions, forgetting repair etc only optimizing minimum cost of assembly!
Can't expect a dealer tech to solve a problem because a GM engineer got a bonus for eliminating a hose or channel inside the tunnel to have the AC condenser water flow to the ground! Having the water stop in the center tunnel and hoping the AC condensate goes out the end of the tunnel, or whatever, does not appear to work in some cases!
If you look carefully, there are more than one problem here. They don't all have the same problem or solution. This appears to be a BGA problem during assembly. Each event apparently requires individual inspection and solution unlike the commonality of other problems like lift reservoir, trunk,... This is where a local certified A technician proves his value. Good luck all and I hope that I don't get it months or years from now.
My dealer doesnt know what they are doing. They fixed and the car is still leaking so now Im asking for a new carpet.
The fact that this issue is not 100% identified and the entire network is not notified on what to do is really pathetic. Its been months and the are still stumbling along with the same problem.
My dealer doesnt know what they are doing. They fixed and the car is still leaking so now Im asking for a new carpet.
The fact that this issue is not 100% identified and the entire network is not notified on what to do is really pathetic. Its been months and the are still stumbling along with the same problem.
07-30-2021, 10:40 AM
My thought is similar. Just appears to be a poor design to me. I'll explain:
Thanks for info! Lets see, condensate water and long pipes carrying warm engine coolant. Looks like a good environment for mold! 
