Engine Light Concerns
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 44
Likes: 0
Engine Light Concerns
I have an 07 and the engine light went on about a week ago. I tightened the gas cap and the light went out after a few blocks of driving. Two days later I got a message on my DIC to check gas cap, upon doing so it was loose and I again tightened such which solved the problem. Two days ago while busy talking-I ACCIDENTALLY used 87 octane while fueling the car. Yesterday, my engine light went on again but has stayed on now. For all those with some knowledge do you think I have a gas cap problem which is causing the engine light to trigger or do you think that one tank of 87 octane may have caused the engine light to trigger and stay on. I know the owners manual states you can use 87 but I have always used 91 or higher. Any input would be appreciated before I make an appointment for a diagnostic check.
Racer
Joined: Dec 2006
Posts: 372
Likes: 1
From: HI
I hope I'm not volunteering his knowledge inappropriately, but Talon 90 is probably the best guy to ask this question to.
If he doesn't know, I betcha he'll find someone who does.
Good luck, and let us know how it turns out- I've got an 07 as well
If he doesn't know, I betcha he'll find someone who does.
Good luck, and let us know how it turns out- I've got an 07 as well
Pro
Joined: Jan 2005
Posts: 667
Likes: 9
From: Melbourne FL
I don't think it's a problem with the 87 octane as the computer will compensate for it. There was a definite problem with the gas cap and many people on this forum have replaced the cap under an SB. Every once in a while my gas cap is difficult to get back on so I'm just going to purchase another one instead of the hassle of bringing it to the dealer.
Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
87 will not cause the check engine light to come on. There are many forum members that only use 87 and they report no problems or lights. You will get many post about how you should only use 91 or higher but I'm sure nobody will say 87 will cause a light unless it's bad fuel of which higher octane would be a problem also.
PHOTOSHOP SPECIALIST
Joined: Aug 2007
Posts: 16,433
Likes: 40
St. Jude Donor '07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I don't think it's a problem with the 87 octane as the computer will compensate for it. There was a definite problem with the gas cap and many people on this forum have replaced the cap under an SB. Every once in a while my gas cap is difficult to get back on so I'm just going to purchase another one instead of the hassle of bringing it to the dealer.
You can either have your gas cap replaced under warranty or purchase a gas cap from Gene Culley (GMPartsHouse.com) at these links:2005 C6 Models:
http://www.trademotion.com/partlocat...layCatalogid=0
2006-2008 C6 Models:
http://www.trademotion.com/partlocat...layCatalogid=0
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 44
Likes: 0
Thanks for the reply guys. I didnt think it was the gas but it just seemed too coincidental that the light went on shortly after filling up with the lower octane. I guess I will make an appointment and go the diagnostic route. I,m sure its the gas cap but why take the chance-AND I should not have to buy a gas cap on a new corvette, I'll let them take care of that!
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
while octane may not be reason enough for a CEL, the brand of fuel can make a difference. was the 87 octane a top-tier fuel? if so, issue is likely just the cap. if you have On-Star, they can tell you what codes have been triggered or you can go to an auto parts store for same help. if you get a running lean code for both banks, reset the codes and try running only a top tier fuel. study done back in early '08showed some correlation between CEL's and fuels used so this issue is not new.
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Intermediate
Joined: Jan 2012
Posts: 48
Likes: 5
From: Gloucester City NJ
I added 87 by mistake
I made the same mistake when I pulled away from the gas station and so I just burned it down to an eighth of a gallon left in the tank and my engine light came on. I know it’s normal that hear knocking and pinging but why would the engine light come on?
does the engine light come on when the low range shows up?
Thanks to all who reply!
does the engine light come on when the low range shows up?
Thanks to all who reply!
Last edited by bsmurf1; Jan 19, 2025 at 08:38 AM. Reason: I got my answer when I submitted
Safety Car
Joined: Feb 2016
Posts: 4,404
Likes: 1,374
From: SC
I made the same mistake when I pulled away from the gas station and so I just burned it down to an eighth of a gallon left in the tank and my engine light came on. I know it’s normal that hear knocking and pinging but why would the engine light come on?
does the engine light come on when the low range shows up?
Thanks to all who reply!
does the engine light come on when the low range shows up?
Thanks to all who reply!
How on earth did you determine you were down to an eighth of a gallon? That's 16 ounces, one pint of fuel. I would expect the fuel pump to be sucking air and the engine running very rough so maybe it would turn on a CEL.
Did you mean 1/8 TANK? That should not cause any problems or CEL.
What is normal about hearing knocking and pinging? The ECU should pull timing to compensate for low octane leading to a slight loss of power, not knocking. Low fuel level does NOT trigger a CEL.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,412
Likes: 3,964
From: Cape Coral, Florida
I made the same mistake when I pulled away from the gas station and so I just burned it down to an eighth of a gallon left in the tank and my engine light came on. I know it’s normal that hear knocking and pinging but why would the engine light come on?
does the engine light come on when the low range shows up?
Thanks to all who reply!
does the engine light come on when the low range shows up?
Thanks to all who reply!
The MIL illuminates whenever something that affects the emissions of the car occurs and the reasons are many…if it’s illuminated head over to your favorite auto parts store and they will tell you what code or codes are present.
Intermediate
Joined: Jan 2012
Posts: 48
Likes: 5
From: Gloucester City NJ
The codes I understand it’s the “Range Low” does that cause a Engine light to come on as I feel 1/8 of tank (haha,)fuel doesn’t seem to warrant a warning in my opinion maybe when it close to fuel indicator RED Zone I should see warnings
Last edited by bsmurf1; Jan 21, 2025 at 12:02 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,412
Likes: 3,964
From: Cape Coral, Florida
Nothing in the fuel quantity in the tanks will cause the MIL to illuminate…get your codes read !!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,412
Likes: 3,964
From: Cape Coral, Florida
Safety Car
Joined: Aug 2013
Posts: 4,424
Likes: 603
From: Minneapolis Mn
This brings up an interesting question. If someone fills up with 87 octane fuel, would adding a bottle of octane booster to the fuel take care of it? Just curious as I've never used octane booster before.