Sounds pretty normal to me to, I get the same effects. Usually when the core is bad you know it. Wet rugs and that unique smell.
Heater Core
Racer
Joined: Sep 2005
Posts: 417
Likes: 0
I've been getting that alot lately when using the air conditioning system. If I run into the store and then run back out to my car and start it up...even if the air is off it kicks out hot air and fogs up the front window. I think thats normal. Maybe someone else will have a technical answer though. I wouldnt worry about it.
Melting Slicks
Joined: Dec 2004
Posts: 3,285
Likes: 52
From: Jacksonville, FL
St. Jude Donor '08 thru '26
I think it could be one of two things, the heater core is starting to leak or there is a condensate drain from the evap box that could be clogged. I don't know where the drain is or what it looks like because I have not looked in the Helm for it....just the thought of going near that stuff on a C4 gives me the 
!
I have had that situation go either way for me. My 72/C3 did the fog thing and it turned out to be the heater core. My 93 Tempo did the fog thing and it was the drain that was clogged.
!I have had that situation go either way for me. My 72/C3 did the fog thing and it turned out to be the heater core. My 93 Tempo did the fog thing and it was the drain that was clogged.
Burning Brakes
Joined: Aug 2004
Posts: 1,175
Likes: 125
From: Dunstable MA
St. Jude Donor '05
On a muggy day, the AC can condense moisture from the air onto the the windshield (usually on the outside), but the heater core will mist coolant onto the inside of the windshield. If it is cool outside and you are in heat mode, the mist is on the inside and it persists ..... and it smells fishy at all, then it is probably the core. Also, if it's the core, it is more likely to do this when the engine is warmed up. It doesn't sound like what you've got.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
GM and most of the OEM's actually have a built in purge or delay a/c function that is to direct the air through the heater vents at start up so that any moisture laden air is directed to the floor and not onto the windshield. It doesn't always work as advertised - usually because it's only for a second or two and high humiditys set the stage for quite a bit of moisture. Do make sure that the weep hole in the evaporator case is open - though when it's completely blocked up, you usually end up with a stream of water out of the heater vents. It's about an 1/8 of an inch in diameter on the bottom of the case. Feel around until you find it or jackup the right side. Use a toothpick or other soft object (I wouldn't poke a screwdriver or metal clothes hanger in there and risk puncturing the Evaporator) to free any obstruction.
Thread Starter
Racer
Joined: Sep 2005
Posts: 484
Likes: 0
From: Redwood City CA
Thanks for all the info, and yes I do need to replace (looks like most) the weather-striping... Who ever had it before me must have just let it sit out in the desert sun, paint faided also but motor strong
....Thanks for replys fellow vetters
P.S. No, there is no fishy smell..
Last edited by Ruff Rider; May 26, 2006 at 03:27 PM.
