Hello! I’ve encountered a mystery I’m hoping someone can help solve. Bought a non-running 2012 f150 with the 3.5 and found one of the intake valves jammed slightly open by what turned out to be a small piece of black plastic. I managed to fish it out through the intake, leak down tested the valve and scoped all intakes and cylinders and all seems in good order now but I can’t figure out where this piece of plastic came from and I don’t want to fire it up until I know there aren’t more pieces about to get sucked into the intake. Checked the air box and intake manifold and there are no signs of breakage. Anyone have a theory where a black plastic part might be breaking up in the turbo system?

 

How big was the piece? Got any pics of it? Welcome to the forum. Let's see the truck mang.

 

Most likely not from the engine itself.
I'm sure Ford is very careful about things like that or it would happen more often.

Could have been introduced by someone working on it with intake system opened or it was put in there on purpose.

A long time ago I worked on a used car lot. My boss bought 2 non running 3rd gen Trans Ams at the auction. One had engine issues, would only turn so far and jam going either direction.

Pulled the heads off and found something copper, either part of a penny or piece of copper house wire partially embeded into the top of one of the pistons. No way it was native to the car.

 

Here is the offending bit of plastic. Going to put it on the keychain as a good luck charm!
I scoped all the turbo lines and the intercooler and didn’t see anything out of order so I went ahead and put it all together and now I’ve got a sweet new truck for three grand and a little elbow grease! Truck has a brand new k&n intake, but I don’t see how this thing could have got in that way because it still would have had to get through the turbo and intercooler which doesn’t seem possible. I’m thinking sabotage? Who knows, but either way I’m stoked! Thanks for the replies!

 

Awesome find, better then picking up a penny !

> I’m thinking sabotage

Agreed, it was a few years ago, but, I fixed a Chevy truck for someone that was sabotaged by the towing company for the airport. Told my customer to tell their friend (who said it ran well before being towed - late coming back from a trip), forget the tow out or the offer to fix, and to just limp it back home. The harness for a few injectors had been disconnected.

Then I noticed the sunroof was taped shut. I solved the 10 year old Chevy mystery why the sunroofs would lose track of where it was and require a $1200 dealer fix and posted the free fix to a Chevy truck board.

No fix though for the leaking intake manifold with no coolant tank ...

Working on a Chevrolet generally makes me glad I drive Fords.