Condensation on Fuel Tank Cap
 

I have a 1993 300SD (w140) with 255,000 miles on it.

I could not get the fuel cap off the tank the other day
due to rust on the inside of the fuel cap. I replaced the
cap but later saw condensation on the inside of the new
cap. The fuel tank was 1/4 full at the time.

Does anyone have any ideas on what may be causing this?
I have had the car for a number of years and never had this
problem come up.

Thanks.

Ralph, I saw condensation on my fuel cap yesterday for the first time in over 9 years. When I saw your post and location (also CT) I thought "aha!", because I was also concerned when I saw this yesterday. Combine all the rain we've had lately with recent overnight temps around freezing - I bet what we're seeing is somewhat climatalogical, and maybe also not the greatest fuel at the pump.

There is a vent for the fuel tank which exits under the car I believe in the right rear which may be clogged. Another way to tell is when you release the cap there is a swoooshing sound of air being sucked in. Run something like a piece of heavy wire up the tube to open it up.

I was always told (by someone) "always keep your tank full in the winter to prevent condensation". So maybe it is just the weather and that your tank is low.

Mike

There is no swooshing sound when I open the fuel tank
but I am getting the DVD for the w140 in a few days and
will definitely look it up.

Thanks!!!

which dvd would that be?