100 unleaded gas Knock Retard is gone. Good or Bad?
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From: I spun my muffler bearing
100 unleaded gas Knock Retard is gone. Good or Bad?
After I used seafoam my car is getting up to 9.5 degrees of knock @ WOT on my scanmaster. I replaced my plugs,wires,oil,fuel filter and still had knock. Today I went to the gas station to put in some 100 octane gas in. @ first I still had knock, after driving the car for a couple miles the knock retard went away. Is that good or bad? Yes I have an LT4 KM,no cats
Last edited by 818camaro95; Nov 29, 2003 at 11:01 PM.
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From: PA
IMO thats bad because it means it was real knock, not false engine noise knock. In theory old engines have carbon deposits which create hotspots and contribute to knock. Seafoam *should* help that.
It's possible that you disrupted the deposits in the engine and the seafoam actually made it worse. I don't have any real experience with this but: I would try the seafoam again, your kind of committed to it now. Hopefully the knock is just because the seafoam knocked some stuff loose and it hasn't been flushed out yet, so maybe another dose of seafoam is the answer to finish up the cleaning job you started ??? Maybe someone else has run into this problem after seafoaming.
-brent
It's possible that you disrupted the deposits in the engine and the seafoam actually made it worse. I don't have any real experience with this but: I would try the seafoam again, your kind of committed to it now. Hopefully the knock is just because the seafoam knocked some stuff loose and it hasn't been flushed out yet, so maybe another dose of seafoam is the answer to finish up the cleaning job you started ??? Maybe someone else has run into this problem after seafoaming.
-brent
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From: I spun my muffler bearing
Update....I used all the 100 octane gas. I always use Chevron,this time I put in Shell gas I didn't get any knock while driving. Do you think the Chevron gas was causing the knock?
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From: Inverness, FL
Originally posted by 818camaro95
Update....I used all the 100 octane gas. I always use Chevron,this time I put in Shell gas I didn't get any knock while driving. Do you think the Chevron gas was causing the knock?
Update....I used all the 100 octane gas. I always use Chevron,this time I put in Shell gas I didn't get any knock while driving. Do you think the Chevron gas was causing the knock?
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Joined: Mar 2003
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From: Fairfield, ca
No i don't think bad o2's will cause knock. But your car will run bad. I'm pretty sure you just got a bad batch of gas. I usually use chevron or 76 gasoline. But i went to a cheap little independent gas station one time and i was seeing 3* of knock because of it.
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From: Jacksonville
Yeah, probably bad gas... pardon. 
Anyway, you probably got gas at a station where they receintly filled the tanks. When they drop a load (of gas), they mix up what's in the tank (water at the bottom, fuel on the top) and water gets into the gas until it settles back down. If you see a tanker filling a station, skip it and go to the next one.
Bad O2's usually make a car run rich. Since the computer can't get a reading it will go into limp mode which runs off a richer table.
Anyway, you probably got gas at a station where they receintly filled the tanks. When they drop a load (of gas), they mix up what's in the tank (water at the bottom, fuel on the top) and water gets into the gas until it settles back down. If you see a tanker filling a station, skip it and go to the next one. Bad O2's usually make a car run rich. Since the computer can't get a reading it will go into limp mode which runs off a richer table.
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