What causes a knock at higher temps?
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What causes a knock at higher temps?
I have a '90 coupe, 6speed. All stock except some small free mods and some mufflers. When my temps get up in the 220-230 range i notice a decrease in performance, and a low end rpm ping or knock. Never occurs when temps are lower. I'm running 89 octane right now, car has 180k on it, engine has 80k.
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I will with the next tank. I had been running the 91 stuff, but then read that i can get a bit better gas mileage with the 89. Havent really noticed any diff. But the knock is new. i haven't thrown any codes.
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Joined: Jul 2004
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From: Hartford WI
Originally Posted by Ronstrap01
I will with the next tank. I had been running the 91 stuff, but then read that i can get a bit better gas mileage with the 89. Havent really noticed any diff. But the knock is new. i haven't thrown any codes.
Lets say I blindfold you and place you in front of me and randomly punch at you. 3 different scenarios. Tell me which hurts more.
1. You are 2 feet away and you have to stand still and not move.
2. You are 2 feet away and when you feel me hit you, you duck a little. If you get hit again, you duck a little more and so on till you don't feel yourself getting hit.
3. You are 10 feet away.
#1 is like the cars of old without a KS. #2 is relying on the KS to retard timing. #3 is like using premium gas.
My vette tells me to use premium gas so your vette motor should need it too. BTW, it is 10.3:1 compression.
