Mercedes-Benz Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
491 Posts
Discussion Starter #1 (Edited)
Recently posted regarding a gasoline odor when driving my 420SEL, most noticable when using the heater or defroster. It was suggested to check the EHA and sure enough, I could see a little seepage when the engine was running, so I replaced the 'O' rings and it greatly reduced the odor. I now no longer see any seepage at the EHA. But I still get a little gasoline odor and when I had things apart, I did notice some 'gasoline varnish' on the sides and back of the fuel distributor, but no visible fuel leak. Based on the pictures posted, should I now replace the large 'O' ring to the fuel distributor head?










To do that, it looks like I need to remove all the fuel lines; is that done at the top of the fuel distributor and all lines along the side? When I re-install the fuel distributor, will I need to make any adjustments? And lastly, are there any 'O' rings or seals that I will need to replace before re-connecting all those fuel lines?

Thank you,
 

·
Registered
Joined
·
13,337 Posts
that varnish is likely from the EHA seals leaking, not the base gasket.

I'd spray the whole assembly down w/ brake clean and observe what's there in a week or so. When the leak is slow the gas often evaporates and leaves that varnish so you may Still have an EHA leak.. If this is the case you'll need a new EHA.

We just went through this on a 560SEL this past week...and I'm seeing it more and more as of late.

Jonathan
 

·
Registered
Joined
·
491 Posts
Discussion Starter #3
that varnish is likely from the EHA seals leaking, not the base gasket.

I'd spray the whole assembly down w/ brake clean and observe what's there in a week or so. When the leak is slow the gas often evaporates and leaves that varnish so you may Still have an EHA leak.. If this is the case you'll need a new EHA.

We just went through this on a 560SEL this past week...and I'm seeing it more and more as of late.

Jonathan
Took me a while to get around to this problem, but bought a used EHA on eBay and installed it this last weekend. At this point, I can report that I have not noticed any further gasoline smell. Installation was simple and no adjustment was made to the EHA. Looks like that solved the problem!

Thanks-
 

·
Moderator
Joined
·
66,897 Posts
You still need to adjust the EHA by measuring the fuel pressure differential between the upper and lower chambers. This will prevent bad idling or the wrong fuel to air mixture.
 

·
Registered
Joined
·
388 Posts
I don't know much about the 126's yet since I just accquired one but I have a 107, 380SL, and I smelled raw gas. It was the worn gasket on the gas cap that caused it. Have you looked at that and perhaps these cars works the same way.
 

·
Registered
Joined
·
491 Posts
Discussion Starter #6
You still need to adjust the EHA by measuring the fuel pressure differential between the upper and lower chambers. This will prevent bad idling or the wrong fuel to air mixture.
I asked about that when I was in for the transmisson modulator adjustment; I was told that most likely I wouldn't need to adjust it, so I installed the newer part and sure enough, engine runs perfect without any adjustment to the EHA. Maybe if it was a brand new part out of the box, it would have been required, but this one was set just right... I've been driving the 420SEL since Monday and am happy with the result... runs good, no gasoline smell in cabin.
 
1 - 6 of 6 Posts
Top