T O P I C R E V I E W
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x2kstangx
Member # 1251
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posted
For some reason, my car was knocking pretty bad at low rpm when the weather was hot(90-100 degrees). What could be the cause of this? Knocking never happens during normal weather conditions.
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QwikStang
Member # 2933
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posted
I was getting the same thing. A really loud pinging, especially going uphill. I was thinking that my timing was off.
anyone know why it does this?
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Blown GR40 Mystic
Member # 476
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posted
cheap gas or timing is off. also may need a tune-up
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x2kstangx
Member # 1251
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posted
i heard and felt it going to the car show up that damn hill! could it be anything else that causes this?
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Sean90GT
Member # 33
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posted
It's a combination of the heat we've been having, your timing setting and the grade of gas that you are using.
Your car is pinging, which is also known as detonation. Your car is running hotter than normal because of the weather. Lower grades of gas (87 octane) are more volatile and will ignite at lower temperatures. So, when you are running hotter your gas is pre-igniting and this causes the knock (which is BAD for your motor). Basically the air/gas mixture is combusting before the piston has reached the top of its compression stroke. The combustion is pushing down on the piston while the crank is still trying to push up on the piston. You noticed it on the hill because the motor was under a heavy load lugging up the hill.
In the hotter weather either back your timing off a couple of degrees or run one grade higher fuel. Some people also suggest running a little cooler thermostat but I'm not a fan of that.
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x2kstangx
Member # 1251
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posted
I only run 91 octane so i will bring the timing down a bit. Thanks!
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1 FLy5O
Member # 2425
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posted
a bad ass exhaust leak...i got one right now..goin to rip it apart 2morrow when i get my new gaskets
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x2kstangx
Member # 1251
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posted
i noticed that the inside of my car has been smelling bad lately... and i have tailpipes! shit, i guess i have to go through my whole car with a fine toothed comb.
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