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Discussion Starter #1
Hey guys... so I've got a 78 mustang ll but it has a 68 v8 302 engine in it. The guy I bought if from said he advanced the timing on it for races... after the first couple of days driving it, I started to hear this really loud knocking sound that got faster and harder as I went faster... I'm scared to drive it. Could it be the timing chain, or maybe worse? What do you guys think? Would really like some feedback. I wanna get my baby on the road as soon as possible. Thanks!
 

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Are you sure it's motor and not drivetrain? Can you replicate the sound in neutral?
 

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Discussion Starter #3
Yes. It knocks while idol. And gets faster and harder as I push on the accelerator pedal.
 

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zodo27 said:
Yes. It knocks while idol. And gets faster and harder as I push on the accelerator pedal.

If you can't identify where it's coming from, have a mechanic look at it.
 

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Sounds like crank bearings my car did the exact thing started out not bad and barely at idle and then when I drove it the more rpm the faster and louder it got. Took motor apart and crank bearings were shot what was left of them anyway. Drain oil and look for soft shavings
 

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Discussion Starter #7
Mxwilly387 said:
Sounds like crank bearings my car did the exact thing started out not bad and barely at idle and then when I drove it the more rpm the faster and louder it got. Took motor apart and crank bearings were shot what was left of them anyway. Drain oil and look for soft shavings
Hmmmm.... I'll get digging in there but is it possible that the timing chain came off? It was advanced and never turned down for daily driving...
 

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zodo27 said:
Hmmmm.... I'll get digging in there but is it possible that the timing chain came off? It was advanced and never turned down for daily driving...
If you still drive it then no way it couldn't have came off, timing off or jump time maybe but that would kill your power somewhere in rpm range and would have rough idle. Atleast from what I know. Maybe pull valve covers off and see if you have busted valve spring, happend on my stepdads car before. I'd check oil first since its simplest but I'm sure someone on this forum will get you in right direction. I'm just telling you off what I know, and personally experienced
 

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Discussion Starter #10 (Edited)
Mxwilly387 said:
If you still drive it then no way it couldn't have came off, timing off or jump time maybe but that would kill your power somewhere in rpm range and would have rough idle. Atleast from what I know. Maybe pull valve covers off and see if you have busted valve spring, happend on my stepdads car before. I'd check oil first since its simplest but I'm sure someone on this forum will get you in right direction. I'm just telling you off what I know, and personally experienced
The car did just die on me while I was driving. I've turned it on but haven't driven it since. Hope its not the crank shaft. I'm 16 and know little about cars. Enough to like change spark plugs, check gaping, and oil but not to take it apart. I also do need to pump the gas when I start it quite a bit. But its not the fuel pump or the oil pump, that's what I thought it was so I just recently had those replaced.
 

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zodo27 said:
The car did just die on me while I was driving. I've turned it on but haven't driven it since. Hope its not the crank shaft. I'm 16 and know little about cars. Enough to like change spark plugs, check gaping, and oil but not to take it apart. I also do need to pump the gas when I start it quite a bit. But its not the fuel pump or the oil pump, that's what I thought it was so I just recently had those replaced.
You ever get a chance to drain oil?
 

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Mine done the same thing, as you step on the accelerator. Do you have headers on it? Mine had a header leak and just tighten your header/manifolds up and see if that might do a difference. Or you can pop the hood and smell and see if you smell exaust fumes from the engine.
 

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zodo27 said:
I'm doing that on monday
Well when you get if figured out even if that isn't the problem post it on here so I could know if I ever come across that problem I will have something else to look for
 

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Discussion Starter #18
mike Franklin said:
But it only took 2 days. Not trying to dash your hopes, just being realistic.
I know I totally understand. How much would it be to get the crankshaft replaced ?
 

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I would drive up to a shop and have them listen. If it needs to be rebuilt the crank can usually be turned. I haven't done it in a long time...I'm too old, but it's worth doing.
 

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Hey, I got my 67 390BB rebuilt last year and 2 months later I heard knocking and I stared freaking out....I go see the engine guy the rebuilt it and I'm ready to go off on him about what this noise was coming out of a 4000$ overhauled engine I paid for. He looks around and takes out a long wrench extension and starts listening to the engine like a doctor would do with a stethoscope. Turns out it was the mechanical fuel pump making all that knocking noise. I would of never guessed. Don't panic until you have answers. Could be something small and not expensive. Good luck.
 
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