C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Fuel, Emission Control, and Exhaust Systems
Not Logged In! Login or Register!  Users Online: 22 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
CorvetteClothing.com
Bair's Corvettes
Mid America Motorworks
VetteBookStore.com

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
SHARK'N
cj5nutz
Featured Links

Buy Now
The Corvette Factories: Building America's Sports Car (Hardcover)
The Corvette Factories: Building America's Sports Car (Hardcover)


GM Corvette 1963-82 (Chilton's Total Car Care Repair Manuals) (Paperback)
GM Corvette 1963-82 (Chilton's Total Car Care Repair Manuals) (Paperback)


The Corvette Dynasty (Hardcover)
The Corvette Dynasty (Hardcover)


How To Rebuild Corvette Rolling Chassis 1963-1982
How To Rebuild Corvette Rolling Chassis 1963-1982



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
11/13/03 2:04am - Original Message: 'Gas smell with full tank'
ricknhis69
Former Member
- Send Private Message


New Berlin, WI - USA

Vette(s):
1969 350/350 4spd A/C convt. - silver with gunmetal interior.

Joined: 3/9/2003
Posts: 281
I know that there have been discussions on this topic before but they have mainly been with the later C3's. My '69 always smells like gas when the tank is full after a drive. The smell goes away until I drive the car again and then its back. This continues until I'm below 3/4 of a tank.

I've been over every inch of the fuel system from the carb all they way to the right rear tire and I've never found a leak. The gas tank is not leaking at the seam and I have not been able to find a substanial area of wetness on the outside of the tank.

Does a '69 have a charcoal cannister? Is there a gasket between the filler neck and the tank body? (this is my best guess as to where some seepage might be occuring) I haven't seen any evidence as to leaking fuel lines. Does anyone else have any suggestions? |headscratch|

____________________________________
'69 350/350 conv.
 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
11/13/03 9:04am - Reply: 'Gas smell with full tank'
markdtn
Former Member
- Send Private Message


Joined: 6/16/2003
Posts: 252
The 69 has a vented cap and no vapor canister. Mine smells a little with a very full tank, but not much after that. I have a new cap-less than 1000 miles. I would make sure the cap was sealing well to start with.
 Reply Reply  Quote Reply w/Quote
11/13/03 7:59pm - Reply: 'Gas smell with full tank'
Mr69Vett
Former Member
- Send Private Message


DE PERE, WI - USA

Vette(s):
1969 350, 4-spd, 3.53 gear, side exhaust, custom mix yellow PPG base/clear Brilliant Yellow

Joined: 12/9/2001
Posts: 231
Same here, gas smell when the tank is full. My cap is also in question, just haven't got around to getting a replacement. One other note is if the cap is leaking fuel it is going around the fill neck onto the collar and then running down the overfill tube. I guess the nest time you fill up, you could take a ride, when you stop, make a point to check up by the cap, I have seen my wet so I know its sloshing in the tank coming out the top and running down. And I Still wonder why I can't get more than 10 MPG |biggrin| |laugh| , couldn't be that way I drive also? |headscratch| , ot a chance |smokin|

Dave
Mr69vett

____________________________________
|IMG|http://www.c3vr.com/member_uploads/201_300/274/yellowvette.art|/IMG| |IMG|HTTP://www.c3vr.com/member_uploads/201_300/274/yj.jpg|/IMG||IMG|http://www.c3vr.com/member_uploads/201_300/274/C3vr2002A.jpg|/IMG|
 Reply Reply  Quote Reply w/Quote
11/19/03 2:31am - Reply: 'Gas smell with full tank'
ricknhis69
Former Member
- Send Private Message


New Berlin, WI - USA

Vette(s):
1969 350/350 4spd A/C convt. - silver with gunmetal interior.

Joined: 3/9/2003
Posts: 281
I have seen wetness on the bottom of the cap but I have never seen any around the collar where the overflow when filling is designed to drain off. The cap does appear to be an original so I think I'm going to try replacing it.

Does anyone know if the filler neck has a gasket between it and the tank?

|headscratch|

____________________________________
'69 350/350 conv.
 Reply Reply  Quote Reply w/Quote
11/20/03 12:43am - Reply: 'Gas smell with full tank'
debrown
Standard Member
- Send Private Message


Mammoth Lakes, CA - USA

Vette(s):
1971 LS5 Convertible with M/T, A/C,Brandshatch Green, Saddle Leather interior, numbers match

Joined: 11/15/2003
Posts: 36
I just recently joined this group, and I don't know if you still have the problem or not,but I had a gas smell when I had a full tank and/or turned corners that caused the gas to slosh in the tank. I discovered gas had leaked out a separator assembly, which is a small black plastic box containing a check valve and mounted on the driver's side of the gas tank. It's connected to the return line from the fuel pump and to the fuel tank by rubber hoses.

In my case, the separator box was leaking at a joint in the box, leaking gas down on the exhaust muffler (and could have been a major problem). So I removed it, after first removing the spare tire container, took it apart at its joint, cleaned it and reglued it with a gasoline resistant glue.

It hasn't leaked since.

____________________________________
   
Click on images for larger views!
 Reply Reply  Quote Reply w/Quote
11/20/03 1:38am - Reply: 'Gas smell with full tank'
ricknhis69
Former Member
- Send Private Message


New Berlin, WI - USA

Vette(s):
1969 350/350 4spd A/C convt. - silver with gunmetal interior.

Joined: 3/9/2003
Posts: 281
Does anyone know if a '69 has this?

|headscratch|

____________________________________
'69 350/350 conv.
 Reply Reply  Quote Reply w/Quote
11/20/03 10:10pm - Reply: 'Gas smell with full tank'
Mr69Vett
Former Member
- Send Private Message


DE PERE, WI - USA

Vette(s):
1969 350, 4-spd, 3.53 gear, side exhaust, custom mix yellow PPG base/clear Brilliant Yellow

Joined: 12/9/2001
Posts: 231
Rick, I just looked thru my assembly manual and yes there is a gasket between the filler and the neck. I have a part # 0f 3826417, not sure if that will be a good GM number though. Looks like there are 8 bolts from tank to filler neck. Good Luck.

Dave
Mr69vett |smokin|

____________________________________
|IMG|http://www.c3vr.com/member_uploads/201_300/274/yellowvette.art|/IMG| |IMG|HTTP://www.c3vr.com/member_uploads/201_300/274/yj.jpg|/IMG||IMG|http://www.c3vr.com/member_uploads/201_300/274/C3vr2002A.jpg|/IMG|
 Reply Reply  Quote Reply w/Quote
11/29/03 4:42pm - Reply: 'Gas smell with full tank'
Paul Borowski
Former Member
- Send Private Message


Massillon, OH - USA

Vette(s):
1968 International Blue conv 1968 Silverstone Silver coupe 1974 Orange coupe 1975 Silver coupe 1980 Yellow coupe

Joined: 1/20/2003
Posts: 6
rick, only Corvettes that had the "charcol canister" had this 'black plastic seperator". They vented to a 1/4" steel line that ran along the driver's side frame rail to the charcol canister. The car's that also had these charcol canisters had "SEALED" gas caps(late '71/'72 |headscratch|). You may have such a small leak(like happened with my '75)that you'll only smell the vapors and NOT see liquid. Could be as simple as a loose or rusted fuel line clamp, to a very, very small age crack in one of your rubber fuel lines, either supply(the larger one) OR your return(smaller line).
 Reply Reply  Quote Reply w/Quote
12/11/03 1:13am - Reply: 'Gas smell with full tank'
ricknhis69
Former Member
- Send Private Message


New Berlin, WI - USA

Vette(s):
1969 350/350 4spd A/C convt. - silver with gunmetal interior.

Joined: 3/9/2003
Posts: 281
Paul, I agree that it only takes a small leak to create a lot of fumes, but, why does it only happen over 3/4 of a tank? I would think that if hoses where the issue I would have an odor regardless of tank level.

Once the level in the tank drops, there is no smell at all.

|headscratch|

____________________________________
'69 350/350 conv.
 Reply Reply  Quote Reply w/Quote
3/17/06 1:09pm - Reply: 'Gas smell with full tank'
Adam Wartell Lifetime Member
Lifetime Member
C3VR Founder
- Send Private Message


Eagleville, PA - USA

Vette(s):
Used to own a 1979 Corvette now owned by JB79

Joined: 11/1/2001
Posts: 14788

So, I just did a search on "Gas Smell" here and found this thread.

My 79 does the same thing, and it is in the shop right now for that very reason.  The mechanic did in fact determine that the tanks leaks at the top when full.  I still have to speak with him directly, in about an hour.  I will reply again when I get more detail. 

One of the things I want him to be careful about, is looking for a build sheet!



____________________________________
-Adam Wartell
NCM Lifetime Member #1222
Founder:
C3 Vette Registry (Join C3VR on facebook)
C4 Vette Registry, C6 Vette Registry
C7 Vette Registry
Corvettes for a Cure

My first Vette, now owned by JB79:

 Reply Reply  Quote Reply w/Quote
3/17/06 2:45pm - Reply: 'Gas smell with full tank'
warbird
Former Member
- Send Private Message


Roseland, NJ - USA

Vette(s):
1974, 454 with 4 on the floor, matching numbers.

Joined: 12/4/2003
Posts: 966
I had the same problem on my 74. I replaced the fuel cap which was bad, but the main cause was the over flow hose which was cracked at the top by the fill spout. It never leaked enough fuel to leave any sign of a leak, but it did emit a strong gas smell. Fixed the hose, no more gas smell,  

____________________________________

(Click image to see a bigger version)
 Reply Reply  Quote Reply w/Quote
3/17/06 11:01pm - Reply: 'Gas smell with full tank'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19496
The filler neck on the later cars(77-82) were sealed by the "Bladder". It formed the seal for the neck, as well as being the bag for the fuel tank. If it is leaking at the filler neck/tank junction, chances are the bladder itself is bad. The good news is, you can completely remove the bladder, and seal the neck with a cork gasket, like the older tanks were.

This is a pretty old thread!! That "search" function is purty neat, eh Adam??

____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
3/18/06 6:38am - Reply: 'Gas smell with full tank'
dwright Gold Member
Gold Member
Moderator
- Send Private Message


Victor, NY - USA

Vette(s):
2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe

Joined: 7/12/2004
Posts: 6757
If you are going to replace the cap, consider a locking cap. With the price of gas always going up, I wanted to make it more difficult for the gas robbers.

____________________________________
http://www.c3vr.com/member_uploads/6301_6400/6346/Copy-of-IMG_267720156754455r.jpg

Save the Wave!
Support the National Corvette Museum   
 Reply Reply  Quote Reply w/Quote
3/24/06 11:14am - Reply: 'Gas smell with full tank'
gs77vet
Former Member
- Send Private Message


Joined: 3/19/2005
Posts: 385
be sure you do not over fill, if you do you might get some splash back around your gas cap. that makes a nasty gas smell.gene gs77vet38800.3441550926

____________________________________

(click to see a larger version)
 Reply Reply  Quote Reply w/Quote
12/26/17 10:47pm - Reply: 'Re: Gas smell with full tank'
Pberns
Standard Member
- Send Private Message


Camano Island, WA - USA

Vette(s):
1969 427 Coupe

Joined: 6/9/2017
Posts: 2
My sending unit gasket was leaking changed it out and the smell went away.

____________________________________
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Fuel, Emission Control, and Exhaust Systems
(Moderator: Adam Wartell, Norsky, Adams' Apple, kstyer)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2018, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30