warriorp

Just picked up my new to me 05 C6 this weekend and it keeps saying check gas cap...so i do a search and have read and tried the different theories on tightning (2 clicks while pulling, 4 clicks while pushing, etc)...didnt work...so i bought a new cap from my local dealer...same story different verse...ive tightned every way mentioned and has been 5 or 6 ignition cycles since the new cap...really PO'ed just got my new toy home and it says stupid crap...any help or suggestions would be greatly appriciated

AirBusPilot

I had a bmw that required, IIRC, 20 ignition cycles to reset the gas cap.

RicK T

You may have seen this already but......

If your cap is new it can take up to 10 ignition cycles before the error will clear. The gas tanks are part of a sealed system and the pressure is monitored as part of the evaporative emissions. Depending upon the severity of the leak it can cause a check engine light or a message on the DIC stating to "check gas cap".

You may have a defective gas cap. This was a problem with the 2005 cars and they are covered under an extended emissions warranty campaign.

When you put the cap on don't press down on the cap and seal, just turn the cap and make sure it clicks at least 3 times. Once that is done make sure that you can just lift it off as that was the defect with the cap, it would never quite make a seal.

warriorp

IIRC???...what is that?...but i will try more ignition cycles...just annoying that popping up on the dic every 5 minutes...thanks!

RicK T

If I Recall Correctly

c6 batmobile

Disconnect your battery for 30 mins and let the system reset its self. That will get rid of the message. If the cap is still bad it will come back though.

warriorp

lol..sorry new one on me

will try that next...will i have to reprogram the windows?

Mez

30 minutes? Is it that long??

foremaw

You may need a new cap, that is not uncommon. Also, I would recommend you do not push or pull the cap. Put it on, turn it until it clicks and that's it.

warriorp

I already bought a new one from GM...What are the odds of it being a defect?

Elite275

I had the same issue recently with my 05. I got a new cap and then cleared the code with a predator after putting the new cap on and not problems since. If you don't have a computer to clear the code, just take a trip to Autozone or some place like that and they'll happily clear the code for you. If it the code comes back then you got another defective cap.

BSSN

My WS6 did this. It would take a tank or so of gas to re-set it. Dunno how many cranks this was.

I smeared vaseline around the caps little rubber gasket that seals/presses against the lip of the fill-neck. Solved it without buying a new cap.

Wayne O

Year's ago I got a check gas cap warning in my 2005. I bought a new gas cap but before I put it on someone suggested I try screwing the existing gas cap on as 'loosely' as possible. The gas cap is still 'on' but I don't attempt to screw it down tight like I might with gas caps on other vehicles. It worked....I never saw another check gas cap warning (and I still have the new gas cap I bought).

c6 batmobile

Its probably less but I normally wait about 30 minutes. A lot of times Ill leave it disconnected over night just cause I dont wanna deal with it right away.

Streetk14

It is possible that there is a leak somewhere else in the evap system. There is much more to it than just the cap. There are the ventilation lines, purge valve, charcoal canister and leak diagnostic pump. The system is designed to allow the fuel tank to vent without causing pollution by allowing fuel vapors into the atmosphere. The system runs a self-test every few drive cycles to make sure there are no leaks in the system.

Keep in mind also that the evaporative emissions self-test only happens after certain conditions are met. It really has nothing to do with ignition cycles. A longer drive is usually required (20+ minutes) before a test is allowed. I'd just clear any fault codes and see how it goes from there.

Andy

warriorp

Thanks for all the input. I'll go clear the codes tomorrow and see how that works.

Thanks!

jsilvz

Had same problem. Cleared codes, no problem. Kinda crazy

foremaw

Not much probably. However, if you have been pushing down hard on your new cap it may also have developed a problem. As Wayne said, they feel like a loose fit but that's how they're designed. Its not like the old days where you need to compress the heavy spring.

warriorp

havent been pressing on the new one...clearing it this afternoon...hopefully that fixes it

Justasheet

There's a recall on 2005 gas caps. Your dealer will replace it for free. Mine did. It's a 10 year replacement item.
Jeff