F150 Bent spark plug

[larryo]

Mechanic found a bent spark plug checking out what sounded like a valve tap on my Yama F150 . Engine has 160 hours on it . He hasn't gotten any further . Any input would be appreciated . Thanks , Larry

 

[lowkee]

Re: F150 Bent spark plug

I would suggest you start looking further

A bent plug would indicate something solid got into the combustion area and got smushed between the piston and plug. Maybe a valve seat? Sounds pretty scary either way to me. Nothing that bends a plug can be promising. Pulling the head will reveal a lot more. Even shining a light into the plug hole may <ahem> shed some light into the situation.

 

[Bifflefan]

Re: F150 Bent spark plug

The are only 3 ways i can think of for the ground to get bent,

1 something went through the motor and hit it.

2 the piston came up and hit it, bad bearing causing the piston to travel farther then normal.

3 its was dropped before it was installed.

 

[robert graham]

Re: F150 Bent spark plug

Just maybe a chunk of carbon broke off inside combustion chamber, maybe a petal broke off a reed valve, maybe a small screw or part from a carburetor. On my VW rail buggy a small brass tube that squirts gas into carb throat from carb pump came loose and entered engine and bent plug electrode, then on out the motor through the exhaust, I guess. Good Luck!

 

[BaileysBoat]

Re: F150 Bent spark plug

Hold the fort good buddy. Very low hours

So, the F150 ran well, but had a noise? Like bifflefan stated maybe the mechanic dropped the plug at removal. Or carbon?

Can you define "bent"? If the engine wasn't misfiring I would replace the plug and do some more checking.

The noise might have been the fuel pump:

http://forums.iboats.com/showthread.php?t=362692

Can you post a pic of the plug?.

 

[rodbolt]

Re: F150 Bent spark plug

at our shop I would do a leakdown test then break out my snap-on BK6000 bore scope and have a look.
bore scope is rather pricey but worth it.
takes still pics,video and audio and has a USB interface with the computer.

 

[Les Robb]

Re: F150 Bent spark plug

Could be a defective plug. The tick and the bend would indicate some contact with piston. I would examine real close for overall length of threads and how about the washer?

 

[Home Cookin']

Re: F150 Bent spark plug

Incorrect plug?
I'm curious--is the tolerance so low that if you forget the washer (on a correct plug) it can get hit? Scary in my imperfect world! Every time they make something foolproof, they make better fools.