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Fuel smell in cabin - New Cadillac owner

Started by Triesch, November 25, 2021, 03:41:52 AM

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Hello all,

I recently picked up a 1968 deville convertible and had some work done as it was very hard to start: carb adjusted, distributer, timing, spark plugs, new battery. As I was driving home I got some gas, and upon heading up a hill the cabin filled with a strong fuel smell, like gas was poured all over the interior. I pulled over and did not see any leaks, and could not find the source of the gas smell. When I was going up the hill the car felt like it was gurgling a bit and lost power briefly when I gave more throttle. I'm new here and searching the general question forum didn't yield any results related to my issue. I would appreciate some sage wisdom.

I am having the car painted to the original arctic blue as a gift to my wife and 4 kids as this will be our weekend cruiser. But I can't give her the car smelling like a a ball of gas.

Big Fins

You said you got gas. Did you just put a few gallons in it or fill it? If you filled it, it could be the cap gasket is aged and not sealing properly. As you were going up a hill I doubt it would be the vent at the front of the tank. It could be the float in the carb stuck down and gas was continuously pouring into the bowl and running all over the engine and also dumping it into the engine cause the bad running condition.

Time to get the grubby clothes on and go crawling around under the car looking for bad lines, leak stains, smells, etc...
1976 Eldorado Convertible in Crystal Blue FireMist with white interior and top. (Misty Blue)
1969 Fleetwood Brougham in Chalice Gold FireMist with matching interior and top. (The Old Man)

Past and much missed:
1977 Brougham de Elegance
1976 Eldorado Convertible
1972 Fleetwood Brougham
1971 Sedan de Ville
1970 de Ville Convertible
1969 Sedan de Ville
1959 Sedan deVille

James Landi

I think "BIG FINS" hit on all of the likely culprits.  Echoing his concerns--- be careful, and get a fire extinguisher. I had a similar (though not quite the same) experience with my 72 Eldorado, that leaked gas when on a hill with a full or nearly full tank--- differences from your experience--- it did not fill the cabin with gas smell.  The gas smell and the loss of power are related, that would certainly cast suspicion on the carburetor; however, that would leave the relationship between the tank fill up, the hill, and the gas smell as coincidental.  Again, echoing Big FIns, and my experience--- check those gas lines.  Another experience with my 67 Eldorado, my gas pump was leaking and leaving a trail when parked.  SO, it might be the gas pump, located on the bottom of the engine or it might be a gas hose or it might be an infrequently sticking float on the carb. By the way, with my 72,  it was leaking ON THE TOP of the gas tank, and a smart, experienced mechanic identified the problem and REPLACED THE HOSE WITHOUT having to drop the tank.  (I'm fortunate to live in Maine where car repairs are generally performed by honest people)  Hope this helps, and happy THanksgiving.  James


U need to check the fuel tank vent line and cap(already mentioned).   Makes sure the right type cap for this model.
These low fill neck tanks will spew when completely full and angled.   The rubber hose will rot off.   I do not fill my tank completely full after I did and parked on a slight grade and came back and there was a puddle under it.   Convertible is more open with the retracting well so vapors can travel from the back.   The airflow causes a back circulation.
I'd have it put on a rack and inspect the whole fuel system.   Top of tank can be rotted, gauge gasket leaking, rotted line or rubber flex. etc.   With old wiring cna be an inferno in waiting.


I appreciate all the responses. The car is parked at my in-laws hidden from my wife  over the weekend before I take it for paint. I had the carb adjusted by the mechanic and I would hope and assume it was done correctly, but I have no way of knowing. The locking gas cap was fairly loose so that may be a culprit, I'll have to take a look at the car next week and will update then.

"Cadillac Kid" Greg Surfas 15364

Park the car facing down hill in the drive or street and look for leaks at the fuel pump.
I chased the same symptoms for a couple days until I found the culprit.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-


At this age a rusted thru fuel line is a definite possibility. 
Bruce Roe


The rubber lines that connect the tank to the chassis metal lines may be your problem.
As mentioned it all needs to be checked.
Brian Rachlin
Huntingdon Valley, Pa
CLC # 22443
I prefer email's not PM's

1960 62 Series Conv with Factory Tri Power
1970 DeVille Conv
1970 Eldo
1970 Caribu (?) "The Cadmino"
1973 Eldorado Conv Pace Car
1976 Eldorado Conv
1980 Eldorado H & E Conv
1993 Allante with Hardtop (X2)
2008 DTS
2012 CTS Coupe
2017 XT
1956 Thunderbird
1966 Olds Toronado


I think there may be a problem with the floats in the carb. On an incline (driveway) it is very difficult to start, but on flat ground starts right up. Would you gentlemen recommend rebuild carb or get a new one altogether? The carb in the car now is definitely not original.

The Tassie Devil(le)

Are you referring to the car parked in your drive with the rear a lot higher than the front?

I had that happen to me once, and the needle valve was leaking, resulting in the fuel overflowing into the intake manifold, filling up one of the cylinders, causing a hydraulic-ing and the only way I could turn the motor over was to pull the plugs out, and spin the engine on the starter to get the excess out.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe


Parked with the front end higher.

It turned out to be the rubber fuel hose from the tank to the hard line. Thanks gents!

The Tassie Devil(le)

Great to know that you found it.

I suppose you have now changed the rest?   And possible should be changing the Vacuum lines as they are made of the same stuff.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

TJ Hopland

Make sure they got all the hoses replaced.   Same thing back at the tank as up by the engine where there are short pieces of hose that connect from the tank to the steel hard lines on the frame and then hose again to the engine.   Most years you can replace the tank ones without dropping the tank.  Its often not fun and a long handle pliers can help but it can usually be done.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason