I have a recurring gas cap problem that is really starting to **** me off!
NO MATTER how I put the fuel cap on it doesn’t feel tight.

The first few months I owned the car I kept getting a CEL.
Back and forth to dealer several times.
The dealer kept telling me “you’re not tightening the fuel cap”
I said, "It doesn't go on very tight"!

I tried a new gas cap (dealer provided OEM)
No difference

To tighten the cap, I have tried:
- tightening to one - several clicks
-a dozen clicks
-no clicks
-I have tried pushing “very hard”, “hard”, “soft”, “not pushing”
-Tightening to “just when it’s about to click”, which is a pain

The “just about to click” method worked for a while, but even then, it really wasn’t that tight … but the CEL stopped going off, so I dealt with it.
Now I’m getting a CEL again.
WTF!

It’s almost like the threads on the fuel pipe are stripped.
But how the hell would that happen, the pipe is metal and the cap is plastic.
I tried cleaning out the fuel pipe threads, but no difference.

With so many people complaining about the CEL, this has had to happen to someone else.
How did you resolve?

 

I had something similiar happen. I finally took my car to another dealership, explained everything the last dealership told me, and they simply replaced the cap with a new one. Viola, problem solved. The mechanic speculated that Mazda got a bad batch of gas caps made.

BTW: That was almost a year ago. Last month I received a notice of a gas cap recall (for 2004 - 2006 I think) gas caps. You might want to have them look into that. Mine didn't need replaced again.

 

gently line up the cap and twist until you get 3 clicks.

If you're getting CEL from doing THAT, then you need a new cap.

 

Thanks for the info.
I'm about due for an oil change, I'll have to mention the gas cap recall.

 

Mine would come on every 780 - 800 miles after they reset the CEL. But the new cap has gone a few thousand miles without any problems.

The first dealer (and original purchase dealer) made me mad telling me I didn't know how to put a gas cap on. The mechanic was an SOB smart a** about it and needed popped in the mouth, but I settled for telling him not to be a smart a**. But that dealer sucked in so many ways anyway. They were the only Costco dealer though, which saved me a lot of money when I ordered my 2006 before they were making them.

 

I had a similar situation with my dealer.
The guy was telling me "you're not tightening the gas cap correctly"
I said, "i've been driving for 22 years, I think I know how to put on a gas cap"

When I stopped having the CEL problem with the "Just about to click" method, I didn't bring up the gas cap problem again.

Other than this gas cap issue, the dealer has been stellar.

 

I had a cell come on a couple of months ago and they found it to be the gas cap. They replaced it under warranty. So far, so good. They said that it is a common problem as there is something in the caps of the '04s that rust inside of it and cause it to leak. So, I would try to replace the cap. If you don't have warranty, it is a cheap fix.

 

I wonder if I'll get a "little" better gas milage.
If the cap is not sealing correctly (loose), seems like the new recall cap would help ... less evaporation and such.

I am getting about 15 mpg with city/suburb driving.
I'll let you guys know when I go in for my next oil change next week.

 

Does anyone know why even the "normal"—not defective—RX-8 gas cap doesn't seem to go on tightly?

I'll click it half a dozen times or more, but when I remove it at the next fill-up, it loosens with no force whatsover—like it wasn't fully tightened. And this is normal, I think—the CEL has never come on (except during start up when all the lights come on, of course).

Does this seem odd? Every other car I've owned had a tight-fitting gas cap.

 

There's an official recall on the old gas cap. Get it replaced.

 

Or just buy a new one STANT GAS CAP Model 10838. It's under $10.00

 

If it aint the cap, check the threads on the filler tube, but I doubt if they are bad.

 

Mine did the same thing, they told me that it was a small defect in some of the RX-8's. If I remember correctly, there should also be a TSB on it.

 

As I said, mine seems to be loose, but with no CEL. And it's NOT in the range of cars mentioned in the TSB. I guess a "normal" RX-8 fuel cap takes almost no effort to open.

 

my gas cap takes a bit of pressure to open. it screws on tightly.

btw, thanks for the 3 clicks = tight tip. i always did 1 click.

 

My original cap was like that. Going on, it felt snug like any of today's "make sure it clicks thrice" caps. I'm in the MSP-13 VIN range (even got a P0455 once), and the dealer replaced it at my last visit. The new one goes on the same. Coming off, it rotates against a spring for about a quarter of a turn, then there's resistance about like you'd expect for a cap that was actually capping.

Ken