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Discussion Starter #1
I know I’ve been all over the place lately but trying to make some progress on this bad boy. If you may recall, I could not get it to start. Well, I walk out, turn the key and it tries to start. Try again, fires up. Still not a clue and still need to track that down.

Anyway, while she was running I let her warm up after being idle for 5 or 6 months. Blipped the throttle and she’s making the noise in the video. Didn’t make it before. Sure sounds likesomething knocking on the valve cover to me. Just wanted to get expert opinion. Only thing I’ve touched on the motor since parking it is an oil change and plug wires.

Hope the video works....
 

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All I can suggest is to rule out any external noises first. Radiator fan, alternator fan, power steering pump, ac compressor, etc. Two of the three blips of the throttle show a delayed knock, the other was pretty spot on. One route would be to systematically take the belts off and try it again.

If you think it is valve covers, I suspect you would be able to feel that from outside the cover. Blip the throttle at the carb and put a hand on the valve covers (may need a helping hand for the passenger side). Also, a long wood dowel or even small-bore PVC pipe works good as a stethoscope.

Sounds good when it's not knocking.
 

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Discussion Starter #3
All I can suggest is to rule out any external noises first. Radiator fan, alternator fan, power steering pump, ac compressor, etc. Two of the three blips of the throttle show a delayed knock, the other was pretty spot on. One route would be to systematically take the belts off and try it again.

If you think it is valve covers, I suspect you would be able to feel that from outside the cover. Blip the throttle at the carb and put a hand on the valve covers (may need a helping hand for the passenger side). Also, a long wood dowel or even small-bore PVC pipe works good as a stethoscope.

Sounds good when it's not knocking.
Copy that, I'll do a little more investigation later this week and see if that's indeed where it's coming from. Thanks! And it does sound pretty good!
 

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Yeah that noise sounds like a fan hitting something more than valve noise. It's too high pitched, fast, and light sounding imho. But check with a mechanic's stethoscope, they're dirt cheap. If it's a valvetrain issue the sound will be louder the closer you poke to it.
 

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1996 EB w/5.8 TOO much lift, 44" Mudders & 5:43-5:38's
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Since its been sitting awhile might want to make sure a varmint hasn't built a nest in there, I know it sounds weird but I live on a farm and you wouldn't beleave what can get in your vehicle or under the hood!
 

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Discussion Starter #7
Since its been sitting awhile might want to make sure a varmint hasn't built a nest in there, I know it sounds weird but I live on a farm and you wouldn't beleave what can get in your vehicle or under the hood!
Down here in MS, it might just be a big cockroach!
 

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Discussion Starter #8
Yeah that noise sounds like a fan hitting something more than valve noise. It's too high pitched, fast, and light sounding imho. But check with a mechanic's stethoscope, they're dirt cheap. If it's a valvetrain issue the sound will be louder the closer you poke to it.
I will definitely check!
 

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It is just too out of phase with the engine to be a lifter IMHO. It does sound like the fan is hitting something. Do you have a flex fan on the engine?
 

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whats been done to the engine? dose it have roller rockers? aftermarekt cam? anythnig special with valvetrain?

taking the belt off to make sure its internal engien first is best check. next i would take off the valve cover and inspect for issues.
 

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1984 Bronco, 4.9L, C6, 8.8, 44 TTB, 3.54 Gears
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My old inline 6 was sitting on garbage motor mounts and transmission mount. The fan was ever so slightly rubbing the shroud. New mounts and she’s back to normal.

If it is the fan, take a look at all your mounts.
 

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I agree with all of the above.
It doesn't sound like a rod knock or lifter tick. It sounds like something plastic is being hit really fast, like the old trick of putting playing cards in the spokes of a bicycle.
An engine knock/tick would escalate with the throttle, and wouldn't just come in like that.

Take all of the belts off and repeat the test.
 
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Discussion Starter #13
Thx all! Could definitely be the shroud and I should have looked closer while it was running. It just sounded really tinny to me. I’ll report back soon.
 

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We can close out this thread. PO cut the fan shroud in half vertically and ziptied it together at the top and bottom to get it to fit. A bolt worked loose and shroud was knocking on the fan. Sorry y'all.
Mine currently zip tied too. Guess I should be on the lookout!
 
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