Strange engine light
 

Iv been using Hess for my X and ran perfectly fine with it without any issue. i leave the car off and fuel like ur suppose to. but when i go to Shell my engine light seems to go off after a couple of days after i fuel. and mobile does that to my car too. is it the gas? or maybe my engine light fuse is giving out? just seems so strange, i use 93 octane on all the 3 gas pumps and hess never gives me any engine lights. any thoughts?

You need a new gas cap...Its sensing that its not screwed in all the way..Even if it really is.

:iagree:

once at a gas station since im in NJ some idiot didnt screw the cap on right and my car warned me by saying

"Gas cap off"

..but i think if the car is older it'll just set the service engine light off

i have a 05 3.0L, i have to order a new one? how much is that gonna cost me... funny feeling its gonna be 50bux at the stealership

i have no clue how much that will cost. but thats weird because i have an 04 4.4 and it told me the gas cap was off.

are you still under CPO?

no i dont believe so, but my cuz usualy checks my bmw for free. ill try to jingle the gas cap around though and give it a try. still dosent explain why it only does it at Mobil and shell and not hess though =/

Here is the part number. Filler cap 16116767740 $17.88 on Realome.com So add 25% more for the dealer = $22.35 + TAX...

Well, you might be lucky and it just be the gas cap, but there are many other things that cause the same symptoms. The fuel tank is sealed by the cap, but also by other components that can leak just like the gas cap can. There is an air pump that slightly pressurizes the fuel tank, a sensor that reads that pressure, and so on. They all cause the same symptoms when they fail. Reading the codes is the only way to determine what it actually is, other than randomly replacing components and hoping you hit the problem one.