Hey all, need advice from an experienced mechanic.
While tightening my harmonic balancer I tried to stop the crankshaft from spinning by putting my hammer shaft between the Crank & the block. Unfortunately, I put it in too far & when I torqued I broke off a piece of the piston - see picture.
So question is, show stopper? Do I need to replace the piston (beyond my capabilities & don't have the tools)? The broken-off piece is the size of a nickel & weighs next to nothing, don't imagine it will effect balance. Break is nowhere near the lowest ring, so won't allow oil into chamber.
Anybody seen this before; I doubt I'm the first one to do this. What do you guys think?
Attaching pictures of broken piece, broken piston, & good piston.
'88 F150, 4.9L
Thanks!

 

No matter what, your (dynamic) balance is now off. How much difference this little bit of weight will make, I don't know.
But.. .
Is the remainder bent and going to score, damage and ruin your (harder) cylinder wall?
What about the resulting stress and perhaps fractures that might cause your piston to break down at speed and destroy your engine?

Is it worth the money, time and grief that it is going to take to replace this?
How old is the engine and what kind of shape is it and the rest of the vehicle?

You would have to take one head off to replace the piston.
Now replace all of the pistons & rings? Without machining the cylinders?
If so, will the increased compression start blowing oil through your (very?) worn valve guides, stems and seals?
Etc, etc, etc.. .
If you are going this far, is it it Time to put a Short or Long block in it?

Gamble and perhaps throw this vehicle/engine away and whatever results if the engine blows out and seizes while being driven? What about the possible resulting ??!!!!! from this?

Safety first, always and foremost please.

Good luck with it!

 

its not hard to replace a piston and yes its going to hurt alot if you leave it please do not destroy your motor and just replace it you got that far down the motor so u can replace it its just how much money are you willing to pay out

 

your balance will most definitely be off with a broken piston. rotating assemblies are balanced down to a fraction of a OZ from the factory I would go ahead and replace the piston like stated above or if the truck isn't worth much, just run it and see how far you get!

 

Thanks for the replies all.
So if the balance is that critical, should I replace all 6 pistons? Thx!

 

No need to replace all 6 but yes you do need to replace that one + the rings and hone the cylinder. If you have 100k+miles would be a good idea to replace all the rings and at least the rod bearings and seals. As a side note I have gotten away with just buying a used piston from a junker and just pop it in the hole complete with rings and rod and hope it seats but not a real good idea