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Discussion Starter #1
Yesterday I changed the IAC valve to get rid of the fog horn noise and when removing the old one I lost a hold of one of the bolts and didn't see where it went. At worst I figured it went into the hole into the intake. I fished around inside the intake through the throttle body with a magnet on a wire and through the hole for the IAC and no luck. When I fished under the intake manifold and around the back of the engine I found two 7mm wrenches, three intake 8mm bolts, and one 7mm bolt. I though I got the pesky bolt and was pretty sure that one of the ones I found was the one I dropped and after starting the car it ran fine even for a pretty tough 45 min. test drive. Today I can here a tapping when I gas it hard but idling and driving slow and even reving high slowly you never hear the noise, but when you give it a jolt of gas sometimes it does it and other times it sounds fine no noise at all. Do you think this could be caused by the bolt being inside the intake? If it made it all the way into the head would the damage be more severe? Would it go all the way though the head and ruin the short block too? What kind of damage am I looking at if I am truly am clumsy idiot? PS I stopped driving it today and plan on taking off the intake manifold and checking out the intake ports on the heads. Are the intake manifold gaskets reuseable? Also, could clogged cats or EGR problems cause this tap? Also, the car backfired twice today when I reved it and it was tapping today, this engine normally has never backfired, could this all be related? Sorry about the lenth of the post, any help is greatly appreciated.
 

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I hope I'm just paranoid. But if it already went into the head would the severe damage be noticeable constantly when then engine is running and not just a light tap/knock that is not consistent and only under a hard pump of the throttle? I know I'm not imagining the noise I'm hearing so I might have head problems anyway and I got the spare set of heads to swap too but do you think it could destroy the lower half of the engine? Does anybody know if one of the 8mm bolts off the intake manifold is small enough to get into or maybe even go through the head?
 

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You could score the hell out of the cyl walls. You guys remember the guy who lost a tin of BB's down his intake. LOL.

Even if it doesnt get into the combustion chamber it could get stuck by a valve. At this point your best bet would be to take you intake off and try to have a look around. Check to make sure intake valves dont have anything stuck by them. While doing my SC install I lost a head bolt down a runner by accident. Lucky for me it was to large to make it around the bend and I could fish it out with a long tweezers. You could also try to look into the spark plug holes...If you do see something....but I doubt you will.

Wow. I dont know what to tell you. You should do what you can and hope you get lucky.

Good Luck.
 

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:eek: YOU FOUND A BUNCH OF SCREWS IN THE ENGINE COMPARTMENT.............Where did they come from??????????? You should not have loose screws hanging around in the enige bay!!!!!!!!!!!!
 

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you need a magantic parts tray!
 

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If anything of any size gets on top of a piston you WILL know. It isn't just a slight tap tap. I lost a checkvalve bb inside a carb once (young kid-stupid, didn't know it had such a thing) and it went all the way and slammed the piston so as the rings were frozen in their grooves. Funny thing is the car arn for some months after removing the now flat bb pretty well. Had real high compression in that cylinder but so what.

If the bolt has seated on a valve that could be a tap tap but it should be at all times. The backfiring could be an open valve.

The only sure thing to do is pull the heads. I learned many a lesson pulling those 289 heads over and over. Sure did love those Victor gaskets.
 

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Kind of unrelated to the 4.6, but I had this happen to an old car I had with a 351W. The stud for my aircleaner worked its way out of the carb and fell through. I ended up pulling the intake to find the stud lodged in the intake valve of the #8 cylinder. Unfortunately it bent the valve which f***ed up the valve guide. I had to pull the head and have a new valve guide pressed in and a new valve installed. What sucks about that story is that the erngine was a freash rebuild with only 2000 miles on it. :mad:
 

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Everyone keep in mind the path the bolt would have to take within the 4.6L intake to get to the head. It would have to go straight up for about 10" and then make the "U" turn and head down toward the head.

That’s a lot of distance for the air to carry the bolt. Bolts aren't very aerodynamic and once the intake valve is closed, there’s no (or very little) airflow in that individual runner. :D

It might get sucked in, but I’m not sure it would.

And if it did, you would know it: Bad, very bad sound. :D

Good luck. :thumbsup:
 
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