While I was taking apart a 2003 3.8L Ford Mustang that I recently bought, one of the many small acorn shells I found on the engine fell into a cylinder through the intake port (red arrow in the photo). If I were to start the engine without taking out that small acorn shell, will there be problems? Is it necessary for me to also take off the cylinder head and take out the acorn to avoid any possible damage?

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    I've seen engines run with a whole lot worse inside. Generally that should be totally risk free. If it were something metal, totally different answer. That should crush, and burn up pretty neatly. I guess it could create a bit of ash that could clog up your catalytic converter, but nah, that little bit is negligible.
    – zipzit
    Commented Jan 17, 2017 at 3:41
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    A few brief questions. 1) you said small acorn shells. By that I expect you mean a shell (and not a complete acorn), something a squirrel would leave after a meal. Something that when flattened is the size of a US dime or smaller. 2) you said fell into one of the cylinders. I take that to mean it fell in an open spark plug hole, and was actually in the cylinder and NOT a fall into an open intake manifold. Is that correct?
    – zipzit
    Commented Jan 17, 2017 at 4:11
  • sorry i didnt specify where exactly it fell in from...hope the picture helps.
    – Miguel M.
    Commented Jan 17, 2017 at 4:37
  • That looks like an intake port, bet you can blow it out with air if you have a compressor available.
    – dlu
    Commented Jan 17, 2017 at 4:51
  • will definitely try it out. Thanks! I hope it works
    – Miguel M.
    Commented Jan 17, 2017 at 5:38

2 Answers 2


You might get away with it, but I sure wouldn't recommend trying. The risks just seem too high.

Instead try either blowing air into the cylinder with a small tube (to leave room for the shell to come out), or sucking it out with a vacuum connected to a small hose. You may have better luck if you turn the engine over by hand to bring the piston up near the bottom of the intake port.

If both of those techniques fail, the next thing I'd try is getting a small USB borescope and using it to find the shell and then decide how to go after it. You may want to look for a borescope with a bendable "gooseneck" for the last few inches so that you can have some control over where it points. USB borescopes are relatively inexpensive (far less than what it will cost you to pull a head) and you'll probably find lots of uses for it.

If all else fails, pull the head – or try running it if you're the gambling type.

  • Good answer, but I personally would not take the risk - the air or vacuum solution would be what i would try. If not, then take the head off as the possibility that the shell could hold the valve open and then contact between the valve and piston would be very expensive.
    – Solar Mike
    Commented Jan 17, 2017 at 10:09

i chose not to risk it and took that sucker out by stabbing it with the tip of a coax cable and pulled it out. Took about a half hour and a lot of frustration but I got it

  • Did you try blowing or sucking it out?
    – dlu
    Commented Jan 19, 2017 at 0:20
  • I was attempting the blowing...didnt really want to get my mother's dyson vacuum (Im 17 by the way) outside onto the mud.. but I did try the blowing only for about 5 seconds until I realized that the blowing would not only accomplish the task, but it would also shoot more gunk around the exposed camshaft and lifters area. So I stopped once I decided not to make more tedious work for myself. However, I am grateful for the suggestions; each one most likely wouldve worked.
    – Miguel M.
    Commented Jan 19, 2017 at 5:32
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    A wise man, never disrespect your mother's tools. Glad to hear you got it out.
    – dlu
    Commented Jan 19, 2017 at 5:34

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