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Discussion Starter #1
ok i think the motors gone

it makes a deep knock when warmed up a 900-1500 rpm range when in gear driving only!!

like if im going down hill 30-50 ish put it in 4th or 5th to coast and at 1000-1500 it will go knock knock knock not in any kind of order but usually 1-3 seconds im between and will immediately go away if i push the clutch in. rarely happens at idle can be heard thru tailpipes also

when in the drivers seat the sound comes from the flywheel/lower intake/clutch area.
i have excellent oil pressure cold and warm never below half on the gauge.
drives pretty good with a missfire now and then idles great slightly a little more sluggish than before but not much
drives alittle warm just alittle but i think thats because no fan shroud

i run 91 octane timing at 10

the motor is tfs heads cam and intake full exhaust and full bolt on

any hopes left for this motor or is it dead?


btw then knock does not speed up it i give it gas it gos away if i give any throttle
 

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Do you have adjustable rockers? Mine did the same thing and i readjusted the rockers and its went away.
 

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It could be a clutch spring or an input shaft with a worn bearing. If it only does it with the clutch out I would go for the clutch first before motor. Maybe check the motor and trans mounts also. Make sure things aren't just moving around.
 

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Does the noise happen when you push in your clutch or when you are driving in gear.

If I'm understanding you, You're saying it only makes a noise when the motor is under a load.

If I was you, first thing I'd do is simple, check your firing order, just to be on the safe side, and then retime it. Since you're running 91 octane, I'd bump it up to 12 or 14 degrees.
 

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Discussion Starter #8
Does the noise happen when you push in your clutch or when you are driving in gear.

If I'm understanding you, You're saying it only makes a noise when the motor is under a load.

If I was you, first thing I'd do is simple, check your firing order, just to be on the safe side, and then retime it. Since you're running 91 octane, I'd bump it up to 12 or 14 degrees.
yea only in gear if i press the clutch it immediately goes away

ill try 14 timing today

and i put some injector cleaner in
 

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Discussion Starter #9
i just took it for a drive still at 10 timing and u can hear it knocking at idle

it sounds like the pistons are hitting the heads thump thump thump

its definitely has less power

its missfiring too i though i got rid of that
 

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Discussion Starter #10
It could be a clutch spring or an input shaft with a worn bearing. If it only does it with the clutch out I would go for the clutch first before motor. Maybe check the motor and trans mounts also. Make sure things aren't just moving around.
i just heard it knock at idle with the clutch in

so its got to bee the motor
 

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Discussion Starter #11
Do you have adjustable rockers? Mine did the same thing and i readjusted the rockers and its went away.

did it actually sound like a deep knock/thump?


or tapping

cause mines definitely a knock
 

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Discussion Starter #12
i put the timing to zero 0 and it knocked less



but i think my problem is just a bad missfire on like 2 cylinders i think

i dont think its knocking


when idling you can see the motor shake weird not in any pattern
 

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Discussion Starter #13
ok timing is at 12 and tryed a different distributor cap and no more missfires so far!!

alot more power like 95% power but i can live with that for now


it still knocks but a little less

it only knocks when going down a hill and i put it in like 5th gear to coast at 1200-1500 rpm and it will knock/shake alittle bit
 

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Discussion Starter #14
ran the codes got

11
10
114 act sensor im going to change that tonight

balance test
90 pass
 

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id pull the oil pan off and check the rod bearings if its a deep knock like your saying.
 

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Discussion Starter #16
it dosent knock if i raise the rpms tho like a rod knock would
 

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i know this is gonna sound off the wall, but check youre Ujoints. and where you yoke goes in the tranny. Always good to get the easy things outta the way.:kooky:

If it aint that, then do a tune up. and keep your car outta low rpms, mine does it too, not bad tho. Hot Rod magazine, I Think it was hot rod, did an article on the 93 cobra and the 93 z28, and they called that 'forward thrust'. Just a common think with the foxes apparently.
 
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