I noticed a dark area around the edge of the fuel door. (white car) I'm guessing vapor leaking at the cap when car is setting in the hot Florida sun? I've never seen this on one of my cars before. Is this a common problem, a defective cap due to age?

 

It might just be road grime sticking to grease off hands or because it's made from plastic?

 

It should throw codes if there's a leak - in some regions at least (not over here, but in USA). So probably not a leak. Clean off and see what happens?

 

Hi and Good Day Capt,

I must admit I saw this post earlier and was shy of looking silly but you've got me now!

Are you used to a white car as I had one a while ago and if you ask anyone in the Aberdeen area of Scotland how living by the sea is so idyllic when there are creatures like seagulls flying about?

I was amazed at how anything considered "normal" to any other driver is sometimes magnified to extremes when you perchance purchase a white car!
My guess is as JagV8 states, it's probably road grime and looks cloudy on the paintwork.

I sincerely hope it wipes off? having said that my old white car was a deisel and they do get mucky around the fuel cap in my humble opinion.

I hope that helps and by the way, white Jaguars are BEAUTIFUL!!!

Cheers, Stu

 

Same thing happens to my car (platinum silver). I've come to the conclusion that it is from brake dust and road grime. It wipes right off with the rest of the brake dust around the door lines and handle.. and reappears as the rest of the car collects brake dust.

 

It was clean a few days ago now very evident along top edge and 2" above. Inside the door it's black everywhere. It may look like mold/mildew in damp areas and we have had lots of rain. BUT this is the only place on the car that is not clean. I took the cap off and looked at it, looks normal but not not shinny and new. I'm still thinking it is leaking a vapor under pressure. I only drive this car a short distance a couple times a week and the gauge shows around 1/4 full. I'm going to price a new cap next.

 

UPDATE / New cap installed for over 10 days and no more black. I also made sure the tiny drain hole at bottom of compartment was open and clean so no rain water could collect there.