I need a bit of help with my '87 coupe. When I am driving at speeds of 50 mph or above with the windows closed tight I get an interior airflow problem. (even changing the fan speed with the vent or ac on changes the problem)
What happens is the interior pressurizes and then the rear hatch glass starts flexing at the lower forward corners. I had the wife drive while I watched this happen. Both forward lower corners of the hatch flex out, release the air pressure then reseat . Then they flex out again and reapat this aciton. When travelling at 70mph this is happening at a rate greater than once a second. While this is happening a noise is generated that coincides with the flexing.
Sllightly open a window and the rear glass immediatley stops doing its deal and the huffing noise stops. But the wind noise from the window open is just as annoying.

Last year I replaced the interior and do not remember even seeing any air discharge openings. At that time I dynamatted the complete floor and sides of the car and cargo compartments. I installed the weatherstripping that was sold in the groupbuy.

I looked a bit yesterday and do not see where the cabin air should be exiting from to prevent this from happening.

Did I inadvertantly cover up the discharge? If so , where is it located at?

Thanks in advance

 

I've had my interior out ( down to the bone on my 86) and never found any venting ports. If there are maybe in the forward dash area?? Is the rear hatch glass adjusted properly? I don't believe the earlier vettes had venting like the newer ones, but I could be wrong. I have a full blown parts cat with pics. I'll take a gander and post back.

 

I have the hatch glass adjusted to require a good firm pressing motion to get the latch to latch.(make sense?) I have had it from just barely to this "firm" position. It is tthe best adjusted like this, but not perfect. Maybe my weatherstripping is so efficient that the interior is to tight. I didnt have this problem before the install.

What type of venting do the later vette's use?

I am thinking of adding a pair of vents, much like most gm's have. Just need to find a low pressure area to exhaust them to. Possibly in the front kick panel area?

 

I might be worth a couple of bucks to ask here: www.gordonkillebrew.com
I will see him later the week and could ask him for you if you can wait that long.

 

Just a shot in the dark (no pun intended Ozzy!!) but aren't the small circular cut outs on either portion of the foward interior door panels where the airflow travels thru ??? Did you block them somehow???

 

Those are the flow through ports from the dash to the door window defroster, nothing more.

 

88 on up has vents in rear speaker trim that go throug a duct out to arubber flapper valve in doorjam it shouldnt be too hard to get used parts on ebay or junkyard and install hope this helps

 

I have seen pics of 88 rear speaker grilles and noticed they are different than my 87's. Thanks for explaining the difference..

The rubber flapper valve in the door jamb, I assume it is located so that the door weatherstrip seal is inboard of the flapper location (with door shut)?

Anyone with a picture of an open door showing this ? thanks

 

Just looked at a picture of a door jamb (thanks chuckgrill).
Now I need a pair of the flappers. Anyone help out?

 

Can you post a pic? I might have what you need...

Art

 

http://i21.photobucket.com/albums/b2...l/PICT2256.jpg

I am looking for a pair of the triangle shaped vents that are mounted in the door jamb, like the one shown here in chuckgrill's car.

(chuckgrill, i stole your photo, hope you dont mind )

 

Yes mate, thats them, straight under the latch pin. What country do you live in? Has any area of the firewall been modified from factory standard?

 

Well this explains why my AC blower works better with the windows cracked open. There could be a benefit of sorts to it, though. I once washed the car while it and the blower were running, and it blew soap bubbles at the weatherstrip leaks. Might be good for troubleshooting.

 

Ozzy, I bet your problem is coming from the top windshield weatherstripping. Take a look with the targa top out and I bet you will see that the weatherstripping is just about flat. The air is entering between the targa top and the weatherstripping. At these speeds the targa is being pushed up letting air enter the cabin between the two. The stripping is flat and not sealing. I had this problem with my 95 vert. When I drove down the road the top was bubbled up and looked shi**y. Replacing the windshield weather stripping fixed it. If you don't want to replace it, I just bought some home window unit A/C weatherstripping from walmart until I was ready to tackle it.

 

Don't know of any vents in the Bose nor have I ever seen any.

Pressure relief valves are on the rear door frames - well at least on the
'89 (and the half dozen or so other GM vehicles I've owned since '73).

 

Its nothing to do with the BOSE, the standard Delco has the same speaker covers. Its not connected to the speakers at all, it just uses an extension of the speaker cover. The extra bit that appeared on rear speaker covers in 88 and up is connected to the vents under the door latch pin via a plastic duct.

 

could someone please tell me the part number that is on the back of either the right or left hand flapper valve, so i can order a pair if all else fails? thanks.

 

a guy on ebay has pair 9$ each + ship i think its running for 3 to 5 days more saw thm them on day of your post and meant to tell you about them but wife wanted to drive her vette to work for rest of summer so iwaxed it and checked it out if shes happy ican buy whatever i want for mine sorry for delay good luck