You gotta love these cars.....always making 'ya think, I'm always catching myself listening, wondering, thinking some more, feeling the car handle the road....what more could anyone want? It's like those brain puzzles that have come into vogue lately....

Anyway, upon fill up yesterday, when I removed the fuel cap, I got a positive air flow out of the filler neck. I've heard it before, but not to this extent. Is there something at work here?

My initial "guess" would be (simple things, like) that the cap's vent is clogged or there's a tank vent clogged, but I would think that would cause vacuum, not pressure.

Googling seems to show that it could be back pressure from the IP, so I thought I'd ask if there is more tendency of the 350SDL to have this or that issue based on your collective experiences?

FWIW, it's a daily driver, never done any fuel conditioner besides injector cleaner. It doesn't seem to be weather/temp related, although you'd think colder would cause vacuum (if anything).

Besides GP and/or injectors missing on initial (cold) start up, car runs well (except for running down in the teens) It really HATES the cold, but I would assume it's a diesel "thing". Well, it runs SO well with temps in the high 20s, that I'm assuming it's a diesel "thing.....

Interested in your thoughts?

PK

Beneath the car- at the level of the axles- you will find fuel lines, and the gas tank vent line. At the end of the vent line there should be a small bell-shapped rubber part. Check to make sure that there is no mud-dauber nest or other obstruction to the vent.

Run the search funtion here and you might find a picture.

Depends on how low the tank was at the time and how much pressure was evident.

If the tank level was between fumes and 1/8-ish when you filled up, some pressure is normal.

If you got a big blowback in your face when you took off the cap, or the tank was half full at the time, then no not normal, you need to check for a vent obstruction.

__________________


Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

Zach,

"R" light was on, so maybe it was because it was so low. Habitually, I fill it somewhere below 1/2 & 1/4, depending on fuel prices that I see.

I'll refill prior to it getting so low next time and see if it repeats....also, I'm due to change oil soon and wil check the vent while under there.

Thanks