Gas cap door will not open when you press the button?

It was super frustrating to stop at a gas station and have to press the floor button twenty or more times to hope that the fuel door would open on my my 2010 California with very few miles on it, and it was still (through 2022) under power train only warranty. The button works, the solenoid operating the plunger works, but horspower to open that fuel door was apparently diverted to somewhere else, ha, ha. I looked briefly on this site for help, but thought that my "friendly authorized dealer" might have a suggestion. Their only suggestion, verified by the Factory Trained Technician, was to replace the fuel door inner black plastic assembly and hope that the new spring was stronger than the old one, at a price of $964.11. Really? Total bill on that annual visit was eleven thousand and change, with nothing really wrong with the car, but, as Clint Eastwood says, "A man has got to know his limitations", and I had reached the limit of my patience. The story has other twists and turns, but I will try to stay on topic here. Back home, with the fuel door open, I thought that the black plastic hinge assembly was not very smooth, and plastic can kind of oxidize, similar to most metal surfaces. What would MacGyver do? He would bust out the WD40 and give that hinge a good spray, and "VOILA", the original spring worked much better with less resistance in the hinge! I had already decided to do something about the wimpy spring, but my initial inspection of the black plastic inner gas cap area showed a rubber seal where it meets the body, that looks like it is retained by push-in rubber points that may not be reusable, and maybe it was included with the nine hundred dollar plastic piece, or maybe that is another nine hundred, and decided that it was better not to risk damaging it. The only visible fastener is a sheet metal type screw with a very wide flanged 3mm Allen socket head, located between the gas cap and solenoid plunger. The flat head is the perfect shape to accept the final thin wire coil of an external helper spring, and I have a secret store, open seven days a week, where I have found special metric fasteners for my 308 GT4, my 1957 coachbuilt Alfa, and just about anything else that needed replacement nuts, bolts and washers. Yup, ACE Hardware! Located half a mile from my home, I bought three different likely springs, but the obvious one was 3-1/4" long that could be stretched to 3-3/8" for the perfect length. The 13/16" diameter fits the round upper lip contour of the inner fuel door perfectly, and the lighter gauge wire fit under the factory screw happily. Fourth photo was a trial fit, and I ultimately placed it in the upper left as much as possible, and then tightened the screw. To loosen the screw, use a 3mm socket driven bit to avoid damaging the tiny inside of the screw, but it can be reassembled with a 3mm T-handle inserted inside the spring. I only loosened the screw enough for the spring wire to fit behind it. Maybe the WD40 is enough, but the spring costs $1.55 with no permanent modification to the car, and we are going on a three day road trip with Ferrari Club of America Monterey Chapter this weekend, and the spring is staying in place for now. If nothing else, remember this story if your own fuel tank door spring becomes inoperative while you are far from home.

Another side note is that the electrical operation of the fuel door, trunk opening, and California roof appear to be interrupted after a battery change, but function again after very few miles of driving "resets" the system. I wrote a year ago that I was fed up with changing batteries every year, and I will explain my solution for that soon, after more than 13 months of testing on my own car, which should apply to many different models. Look for that post with photos soon.

In closing, I will say that my local dealer could have been a Rock Star in my eyes if they fixed an annoying problem with a quick spray of WD40, instead of hoping that they could suck another grand out of my wallet with (another) unrequired replacement of parts. This video by one of my favorite car people pretty much sums up my feelings: https://www.motorauthority.com/news/1134983_here-s-why-jay-leno-doesn-t-own-ferraris
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

For the gas cap door, trunk, roof, and smog history, the car resets itself after being driven, with no operator envolvement, and the car always starts when you hit the starter button, for a 2010 California (and likely other models). I changed batteries before my very recent scheduled annual dealer maintenance, and there were no ill effects at all, except that the history available to the dealer recorded no speed over 80MPH, due to the short history period and heavy traffic areas between my home and the dealership. Watch soon for my battery replacement and modified charging arrangement to be posted here.

 

Do try the WD40 first, before installing the spring. I live next to the hardware store and already had the $1.55 spring. Stuff a paper towel in the fuel door area to catch the extra fluid. Before spraying, do study the slow movement of the door as you move it with your fingers. Spray from the top with the little spray tube, and then from the side. The difference in movement is amazing, and needs to part of the regular maintenance plan at Ferrari. Although the hinge looks very similar to most every other car, I have never heard of this problem with other brands of vehicles.

 

The red draw string pulls in the latch plunger, but most of us have plungers that work perfectly, and the problem is that the friction in the dry plastic hinge overcomes the strength of the wimpy $964 Ferrari hinge spring. I also was wondering if there was stiction with the rubber door gasket nubs wanting to hold the door tight at various temperatures, and I greased those nubs, but it made no difference. WD40 on the plastic hinge should be enough for most everyone, but three fill ups on the Monterey Chapter FOC drive to Copperopolis last weekend yielded perfect door opening with one touch of the button, with the helper spring still in place.

 

I wanted to provide an update on my gas tank door issue. It works perfectly since I gave it some attention. While my car was at the dealership for an expensive service, they told me that there was no known fix for the door not opening except to spend $964.11 to replace the plastic hinge. On my own, I blasted it with WD40, and that is probably enough to keep the plastic hinge operating on any model Ferrari. If you have any doubt or further problems at all, go buy a hardware store spring and secure the end under an existing screw inside the gas cap compartment, which can be removed later with no trace of it at all.

 

WD40 regularly on the plastic hinge should be enough, but the security of the pull cord in the trunk is comforting.