Can this be my problem?

FastBird91

Registered User
A couple days ago my friend and i made a bet. He lost the bet so he had to fill up my SC with gas. I gave him the keys and told him "filler up". He drove off in my SC and went to the gas station to fill it up. He put $45 in gas in it and returned. I forgot to tell him he needs to put 91 octane in it. Now it rides rough as expected, and makes a horrible undercarriage sound at about 1000 rpm's when im accelerating. It also makes that noise when im under hard acceleration. I pretty much hear it all the way around. It sounds like my catylictic converter is pinging really bad. I dont think that can be it because i had new performance ones put on about 10,000 miles ago. Can this 87 octane be my problem???
Thanks
 
Detonation

Most likely what you are hearing is detonation due to the low octane fuel. It can get as bad as the sound of a deisel truck at times. When you hear that thats BAD. Too much detonation will blow headgaskets, and even burn holes in pistons. You could pour in some octane booster to bring the octane up a bit. Try at least one bottle and see if it subsides. I would still take it easy on her until the lower octane fuel is burned off.
Good luck!
Bill
 
well i got it down to half a tank and refilled it with "91" octane and its much better. I dont hear any detonation and its running at about 80% instead of 20%. Thanks Bill
Bill
 
If it ever happens again, instead of driving it down to a half a tank, just siphon out a couple of gallons and replace it with unleaded racing fuel. It is expensive stuff, but cheaper than paying for a new motor.

Any octane booster you buy on the shelves is a joke. If you read the bottle it may say, "raises octane by 10 points" what it doesnt tell you is that this doesnt mean you would go from 87 octane to 97.
 
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I used to use the stuff until I was educated about boosters. There are a few that do raise the octaine conciderably but they are rare and usually very expensive. The best way to raise it is to throw a gallon or two of 100 in the mix.
 
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