Recent Topics
cstoremotoroil.com
by AirgunSavant
Today at 09:37 AM
What's good/bad about a 2006 Mazda 5?
by 55Test
Today at 09:30 AM
My 1st air impact - go with 3/8" or 1/2" drive ?
by Cressida
Today at 08:55 AM
Silly me
by jay929
Today at 08:41 AM
15K oil & filter
by marine65
Today at 08:36 AM
Battery or starter
by Dallas69
Today at 07:56 AM
Napa Syn 15w50 to replace BradPenn 20w50 in 454bbc
by FlyNavyP3
Today at 07:51 AM
Real Main Seal Leak ? ? ?
by larryinnewyork
Today at 07:35 AM
Gov't wants to lower speed limits for trucks
by JetStar
Today at 07:11 AM
GM 55560202 longlife cut open - 10782km
by turboseize
Today at 04:54 AM
Coolant Question.
by Farmer
Today at 04:20 AM
Stocking up for the Eco
by buck91
Today at 12:25 AM
Newest Members
therhett17, glldprimr, krankshaft, Tony_Rhed, greasemonkey1
58935 Registered Users
Who's Online
60 registered (AKA, AnthemBassMan, AirgunSavant, 1JZ_E46, 97f150, 2004tdigls, 5 invisible), 1665 Guests and 35 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
58935 Members
66 Forums
253619 Topics
4163438 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Topic Options
#2767398 - 10/09/12 09:26 AM Symptoms of a bad gas cap?
wolf_06 Offline


Registered: 06/11/12
Posts: 461
Loc: Atlantic, Canada
Any of you experience a bad gas cap? If this can affect engine performance, fuel trim or fuel pressure? fuel economy?

Thanks!
_________________________
2011 Chevy Cruze 1.8L 6AT
AC Delco Dexos 5w30 - OEM filter

Top
#2767401 - 10/09/12 09:30 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
Quest Offline


Registered: 12/19/04
Posts: 7355
Loc: beaver land EH?
on OBD-II cars: a bad (not sealing properly) gas cap will throw you a code.

Q.
_________________________
"Internet discussion boards act as echo chambers for conspiracy dittoheads" A.Allen

Top
#2767404 - 10/09/12 09:32 AM Re: Symptoms of a bad gas cap? [Re: Quest]
Charlie1935 Offline


Registered: 05/18/08
Posts: 611
Loc: DuQuoin, Illinois
It will give a code for evaporation system leak usually.
_________________________
Charlie

Top
#2767417 - 10/09/12 09:53 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
440Magnum Offline


Registered: 02/01/09
Posts: 8304
Loc: Texas
Electric fuel pumps for EFI generate pressures on the order of 50 psi, the gas cap holds a pressure of 2-3 pounds. So at most its going to make a few percent difference in fuel pressure, and most likely not even that since the fuel pressure is usually regulated. So I'd say you'd never see a difference in performance at all, just the code for an evaporative emissions fault.
_________________________
'66 Dodge Polara & '69 Dodge Coronet R/T both 440/727
'08 Ram 1500 4.7/545RFE
'12 Challenger SRT8 392/6-speed
'99 Cherokee 4.0, '11 Grand Cherokee 3.6

Top
#2767479 - 10/09/12 11:19 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
WishIhadatruck Offline


Registered: 05/09/06
Posts: 1323
Loc: Grand Rapids, MI
The only thing I've ever noticed is that my check engine light comes on. I've never noticed a change in how the vehicle performs.
_________________________
1996 Buick Roadmaster Wagon
2014 Cruze Eco Manual
2003 2500 Suburban, 8.1L

Top
#2767495 - 10/09/12 11:39 AM Re: Symptoms of a bad gas cap? [Re: wolf_06]
Donald Offline


Registered: 03/21/04
Posts: 17179
Loc: Upstate NY
I drove for a few miles with the gas cap held neatly in the gas flap. No code or anything.
_________________________
2015 Subaru Forester 2.5 engine/CVT
2015 Ford F250 w/Powerstroke
2001 Jeep Grand Cherokee Laredo 4.0- sold
1999 Dodge Ram 2500 w/Cummins- 4-sale


Top
#2767501 - 10/09/12 11:43 AM Re: Symptoms of a bad gas cap? [Re: Donald]
Trav Offline


Registered: 11/20/06
Posts: 14206
Loc: MA, Mittelfranken.de
It wont until the system runs an EVAP test.
_________________________
ASE L1, Master. Deutsch Meisterbrief.

Top