I have a 98 F150 4.6, last week I was getting a misfire, my truck has 160km on it. I changed the plugs and noticed cylinders 5 and 6 (front Drivers side) had coolant in the top of the plugs. I believe this was my problem causing the misfire. The truck ran good again after I changed the plugs and cleared the moisture, but after a week its back again. I don't beleive the coolant is coming from a leaking hose. After doing a little reseaech on here it looks like it maybe a leaking intake gasket. I am wondering if anyone else has come across this, and if anyone has changed the intake gasket, Is it a big Job?

 

I have the same problem. Is the LIM gaskets a problem on the 4.6's? I was just looking at a new engine thinking it was a headgasket, if it's the LIM that's a piece of cake compared to a top end job or installing a new motor.

 

the coolant is just getting above the sparkplug no into the cylinders, not sure where else it could come from.