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The Mercedes-Benz W126 is a series of S-Class automobiles manufactured by Mercedes-Benz between 1979 and 1992. Premiering in September 1979 as the successor to the W116 line, the W126 was the second generation to officially bear that prestigious designation, an abbreviation for the German Sonderklasse or "special class." The W126 was initially offered with straight-six, V8, and a turbocharged diesel engine for the sedan. A C126 2-door coupé versions was introduced in September 1981.

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gas fumes but no apparent leak

gas fumes are apparent but no apparent leak

Update (09/02/2021)

Hi Brandon, Thanks for responding. I’ve had this car

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for 21 years. It’s a 1989 560SEC. When I got it the mileage was 37,400. It now has about 79,000. It looks like new inside and out and drives very well. I notice the fuel smell occasionally while driving it, but when I put it away in the garage, the smell is extremely strong. All I’ve done is to look under the hood for anything obvious. I’ve also check the gas cap and when I remove it, there is some suction. I plan on putting it up on a lift to see if there are any fuel lines leaking. There is no pool of fuel ever, even immediately after driving it.

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what have you checked? When can you smell the fumes? Where is the smell coming from that you can discern?

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@marhil if you have a lift to use... I'm jealous. But yeah check the fuel lines all the way to the motor. Not exactly familiar with these motors, but if it has an air cleaner on top of a TBI or carb setup, take that off as well, and try running the motor. Use a flashlight to look in the engine compartment and see if you can see anything. That engine bay looks very cramped (compared to my 1994 chevy suburban... so much room.in the engine bay!!) Check your plugs also, make sure they're good. If they're going bad, or the wires are, you may not be burning all the fuel, so you'll get a gas smell from the exhaust

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@marhil also, you only have 79k on it? Wow... for that age thats actually quite impressive. My 1994 suburban has 267k on it. Haven't owned it for long though...

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I have the same exact problem with my 1989 Mercedes 560SL & looking for a solution! Did you ever resolve the problem, Gordon?

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The fuel tank may have a fuel vapor hose that runs to the front of the car to a charcoal cannister. if the vent hose is loose, you won’t get a fuel drip, but will smell fumes. This is covered by an emissions warranty for a long time. Take it back to the dealer.

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I have the same problem with my 1989 Mercedes 560SL & looking for a solution. Emissions warranty on a 32 year old vehicle!? Did you ever resolve the problem, Gordon?

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Electro hydraulic actuator valve by Bosch. It’s a small plastic and copper valve on the side of the fuel injector distributor. It was leaking just enough fuel to make the smell. Replaced it and smell was gone.

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Gordon Opp crwdns2934231:0crwdne2934231:0
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