Open the door, find a little black foam ring, where is

where did you find it? can you get a closer pic?

 

are there any open holes in the front of the door where it closes on the jamb? i'm thinking an hvac vent.

 

what is the outside diameter?

 

well done!

 

That looks like a fastener that holds the inner door panel to the metal framework. Maybe the washer came off during assembly at the factory? It could either mean one of the panel fasteners is missing it's washer, or it was just an extra washer. I'd suspect it's the former, maybe just hang onto it, put a twist tie on it and label.

 

if it's under 12/12, it's under warranty.

 

Still, every time a door panel is pulled off, you run the risk of breaking those fasteners, or having them tear out of the panel. I'd be inclined to just leave as-is, if you're not hearing any rattles, seeing looseness. That's assuming there's one fastener inside there missing that washer.

 

I once asked a service writer (many years back) if it was normal to hear a whistling sound for a minute or two, after the car was parked on a hot day, from the gas cap area. Correct answer would have been "Yes, it's the cap, it's meant to vent under those conditions". What they did: drill a hole through the cap, to "fix" it.

Times have changed, you'll very likely fare better, but be careful what you ask those buggers, lol.

 

I'm sure everyone has their experiences, I remember my 78 Chrysler (bought used from a relative) I was going to change the transmission fluid but decided to take it to a dealer since draining the torque converter was beyond what I wanted to do myself. But after what they charged me, I decided from then on I would just change the fluid myself at more frequent intervals to make up for not draining the torque converter. So the next time it was due I bought the fluid, gasket and the filter that is located inside the pan. Took the pan off, looked for the filter, not there. Even worse the two screws that attached the filter were missing so I couldn't attach the new filter. So I had to button it all up and fill it as is. Later went to the dealer and had to special order the two screws. I remember the parts guy asked me what happened to the original screws, and I said ask your mechanic.

 

Yeah similarly, I ended up buying a new gas cap, not worth going another round with them.

The 3rd gen and onward engine oil filter is another bugaboo: at least one report here, someone doing their first diy oil change after dealer service, discovers there no filter inside the (permanent) housing.

 

I had something similar - think it was my early '70s VW, the carburettors were starving of fuel on long steep hills. I mentioned another issue - that when I took off the fuel cap, there was a gushing of air sucking inwards. The mechanic suggested that it might be sealed too well - this was before charcoal canisters. I eventually cut a minuscule groove in the rubber seal of the cap. 2 problems solved.