Hello to all.
I need help from the experts of this wonderful forum.
My 1992 500E (with FMBSH) is not even a weekend car, it stays parked in the garage for long periods of time (ok, I know that is not good for the car). Because of that, sometimes I use it as daily car for 2-3 days, so it can run a little. Then it returns to the garage for more weeks of "hibernation".
2 months ago I took it for a drive and it started to smell gas. The smell was becoming more noticeable and I tried to find the source of it. In the outside, there is no smell at all, but inside the car was very present. The smell is not coming from the dash vents, it comes from the rear of the car, being strongest on the trunk. I took the car to a mechanic, put it on a ramp and no fuel leaks were find in the outside: all was very good in the fuel pumps area, including all fuel lines. Most of all, no gas smell and no leaks, not even a tiniest one.
But inside the trunk, the gas smell was very strong. I removed all the coverings of the trunk and find that no apparent leaks were present, nothing from the fuel sender unit, nothing on the filler neck, nothing on the vent tube coming from the fuel neck area. Thinking about the simplest things, I bought a new original fuel cap to see if it was the problem. Everything remained the same with the new fuel cap. Then I find gas residues next to the area where is the fuel strainer (or gas tank tank filter), under the gas tank. I went to the Mercedes dealer to buy a new strainer, new filler neck seal and the hose that goes from the tank to the fuel pump. I find that that hose is not available at Mercedes, not even in Germany. It has to be manufactured and that may take a few weeks. My mechanic (the car has FMBSH, I only use my mechanic for simple things like changing brake pads and even in that case, I use the original ones bought at Mercedes dealer) said that changing the fuel strainer is difficult in the 500 because of the size of the differential and that the easiest way of doing it is by removing the fuel tank. According to him, that is easy than lowering the diff to get access to the strainer from under the car. What do you think about that? Is that true or is he wrong? I'm still waiting for that fuel hose from Mercedes, so no repair work will go on until it arrives. For me, it looks like a very big job just to replace the strainer and a fuel hose.
I'm not going to drive the car, since I can have a fire or something. But often I check the trunk to see If I have new developments on the leak. I've clean everything but the strong gas smell remains. After the car was parked for 3 weeks, today I went to see the trunk and I get something: on the left side of the fuel tank when looking forwards, a noticeable leak has appeared inside the trunk. As always, in the outside there isn't nothing, not even a single drop of gas or smell of it. If the leak is evident on the left of the gas tank, that can't be the fuel strainer, which is on the right side. According to the diagrams, in the left are the returning fuel lines. Can that be the source of my leak? What do you think?
My car runs great. The only thing that may not be normal is that I always have gas wetness on the fuel cap seal, doesn't make any difference if the tank is full or empty. The second thing is the "wooch" noise and vacuum pressure everytime I remove the fuel cap after I run the car. I bought the car in 2007 and always did that.
I appreciate all help that you can give me.
Thank you very much in advance.
Best regards
António
I need help from the experts of this wonderful forum.
My 1992 500E (with FMBSH) is not even a weekend car, it stays parked in the garage for long periods of time (ok, I know that is not good for the car). Because of that, sometimes I use it as daily car for 2-3 days, so it can run a little. Then it returns to the garage for more weeks of "hibernation".
2 months ago I took it for a drive and it started to smell gas. The smell was becoming more noticeable and I tried to find the source of it. In the outside, there is no smell at all, but inside the car was very present. The smell is not coming from the dash vents, it comes from the rear of the car, being strongest on the trunk. I took the car to a mechanic, put it on a ramp and no fuel leaks were find in the outside: all was very good in the fuel pumps area, including all fuel lines. Most of all, no gas smell and no leaks, not even a tiniest one.
But inside the trunk, the gas smell was very strong. I removed all the coverings of the trunk and find that no apparent leaks were present, nothing from the fuel sender unit, nothing on the filler neck, nothing on the vent tube coming from the fuel neck area. Thinking about the simplest things, I bought a new original fuel cap to see if it was the problem. Everything remained the same with the new fuel cap. Then I find gas residues next to the area where is the fuel strainer (or gas tank tank filter), under the gas tank. I went to the Mercedes dealer to buy a new strainer, new filler neck seal and the hose that goes from the tank to the fuel pump. I find that that hose is not available at Mercedes, not even in Germany. It has to be manufactured and that may take a few weeks. My mechanic (the car has FMBSH, I only use my mechanic for simple things like changing brake pads and even in that case, I use the original ones bought at Mercedes dealer) said that changing the fuel strainer is difficult in the 500 because of the size of the differential and that the easiest way of doing it is by removing the fuel tank. According to him, that is easy than lowering the diff to get access to the strainer from under the car. What do you think about that? Is that true or is he wrong? I'm still waiting for that fuel hose from Mercedes, so no repair work will go on until it arrives. For me, it looks like a very big job just to replace the strainer and a fuel hose.
I'm not going to drive the car, since I can have a fire or something. But often I check the trunk to see If I have new developments on the leak. I've clean everything but the strong gas smell remains. After the car was parked for 3 weeks, today I went to see the trunk and I get something: on the left side of the fuel tank when looking forwards, a noticeable leak has appeared inside the trunk. As always, in the outside there isn't nothing, not even a single drop of gas or smell of it. If the leak is evident on the left of the gas tank, that can't be the fuel strainer, which is on the right side. According to the diagrams, in the left are the returning fuel lines. Can that be the source of my leak? What do you think?
My car runs great. The only thing that may not be normal is that I always have gas wetness on the fuel cap seal, doesn't make any difference if the tank is full or empty. The second thing is the "wooch" noise and vacuum pressure everytime I remove the fuel cap after I run the car. I bought the car in 2007 and always did that.
I appreciate all help that you can give me.
Thank you very much in advance.
Best regards
António
