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Discussion Starter · #1 ·
All,

Good afternoon everyone. First time on the forum.

I would greatly appreciate any advice anyone can give me in the steps of troubleshooting my 460 knock.

I have a 70s 460---REBUILT 8K miles-- in my 1955 Ford F-100, its always ran great, hardly any troubles....

In the past couple of years Ive noticed some ANTI-FREEZE in the BOTTOM of the oil pan. AF and Oil isnt mixed, maybe 1 cup of AF accumulates after a while of sitting there. I pressure tested the radiator and noticed some small drips coming out of my intake manifold on the front drivers side.

I changed the intake manifold gasket the FIRST time, had a small oil weep/leak out of the rear china wall. Dang!

I changed the intake manifold gasket the 2nd time, gasket held great, no leaks.....BUT now I swear I hear a knock in the engine and Im really in need of helping to determine where its coming from. I was very careful when I was scrapping off the gasket and cleaning everything up. Had paper towels in all the holes. Vacuumed out all the debris. Could be a coincidence its knocking, but maybe it isnt.

I initially thought it might be my timing and having some spark plug knock, but I timed it again and it seems correct.

I kinda hear the knocking really while its idling if I put my head down by the engine, but when I give it some gas I can hear something knocking around in there.......

WHAT STEPS CAN I TAKE TO TROUBLESHOOT? Remove the spark plugs one at a time and see if the knock goes away, etc, etc???

Thank you so much!!!

Patrick

Eng: D1VE-6015-A2B
Head: D3VE-A2A
Edelbrock Performer Intake 2166
Edelbrock 750 CFM
 

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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Can you feel it like it's a hard thumping or more of a ticking if you put you hand on the valve cover? More on one side or the other?
 

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Discussion Starter · #6 ·
Ok.....I THINK I can feel a little more knocking/ticking on the passenger sides valve cover.....

I picked up a mechanic's stethoscope from HF....I can definitely hear more of a ticking/knocking from cylinder 4.

I did have to remove the valve cover when I changed out my intake manifold gasket, but didnt see anything wrong in there.
 

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Discussion Starter · #7 ·
Total shot in the dark....I changed my passenger side valve cover gasket from a cork gasket to a rubber one.

Could the rubber gasket be just slightly less thick than the cork one causing the rockers or something to ping on the valve cover?
 

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At this point I'm thinking possibly a rod bearing?? They'll spin and not drop oil pressure like you would if it spun a main bearing. Since it's localized I think it's spun a rod bearing. I'd really like for someone else to chime in here with a second opinion, maybe someone else has more input they can give on this before you start tearing stuff apart.... I'm not having a complete brain [email protected] and missing something like an exhaust leak since its next to the back of the exhaust manifold am I?
 

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Discussion Starter · #11 ·
Well, call me crazy, but after farting around with it for a while...I put the stethoscope on it again and I hear it better over on the Drivers side, position 8.....

Took the valve cover off. It appears the 7th rocker back, counting at number 1 at the front Drivers side appears fairly "wiggley"...Way more wiggley than the others...Spun the engine around and it does tighten up, but not as firm as the others......

o_O
 

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Turn the engine over till the 8th rocker back starts to open up, then loosen up the 7th one and torque it back down to 17-20 ft pounds... If it's still loose then you may have found your ticker....
 

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Discussion Starter · #15 ·
Great info. Ill try to look at the 8th rocker tomorrow and re-torque the 7th one.

Never had any milkshake/AF/OIL mix. It was always pure antifreeze that poured out first, then the oil.

The truck is something I rarely drive, so I suspect I got lucky and it never mixed up that much if at all since it sits so much. Kids take up most of my time anymore.
 

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If you really think it's a rod bearing you can always go old, old school and put the front bumper on something that will not move, then load the engine. If it's a rod bearing, it will shut up when loaded.

Nothing like dropping the pan and looking, but it's a lot easier.
 

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Discussion Starter · #19 ·
Well. I wish I could report that re-torquing that rocker fixed my tick/knock....But it didnt. Its till knocking. Not sure what Ill do, take it somewhere and they can tell my what it is, unless anyone has anymore ideas?
 

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Why not remove your oil filter, cut it apart and inspect for metal piece's in the filter.
I would do that before pulling the engine. Since you are not sure if it is really knocking or not.
The knock may not be coming from the engine but somewhere else in the drivetrain. Harmonic's are hard to find because something can be making noise in the rear end and it will sound like it is in the engine.
I have chased these before and they are hard to find and will make you pull your hair out.
Greg
 
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