99 F250 4x4 truck running rough. 220K miles.
plugs replaced earlier.
Mechanic found antifreeze in the two cylinders.
cylinders was cleaned out. running ok for while, but starting to get rough again. seems to get worse after truck sets awhile.

wanted to know if others experienced similar problem.

 

That sounds like a blown head gasket...

 

i was thinking same.
problem not real severe.
any idea whether a fuel additive will displace the antifreeze?

 

Which two cylinders? And is it IN the cylinders, or down the plug holes?

 

Before you crack a piston I would have the heads off. Been there with a 99.

 

Okay, I'm probably going to get fried for this, but we're talking about a '99 250, so its about 12 years old with 220K on it. I threw a can of StopLeak in an old buick and got an extra 5 years out of it. An extra 5 years would make the truck 17 years old. Why incur the expense of rebuilding anything if its just a leaking gasket?

 

can't remember which cylinders.
antifreeze was down in the cylinders.
definitely not interested in putting mucho dollars in at this point.
looking for cheap (effective?) solutions first.

 

But on the flip side, one could also argue that using such an additive could also end up plugging up some very small, important coolant passages that could also accelerate its demise.