I have a 1996 Ford Mustang GT with the 4.6L V8. My car's engine had the
famous junky intake manifold that leaked coolant. About 2 years ago I
bought an aftermarket intake with the improved design and installed it
myself. The intake fit perfectly and worked perfectly...with NO leaks
anywhere. I was VERY satisfied.

But 2 weeks ago, my Mustang developed severe hesitation under hard
acceleration. The car basically acted like it was running out of gas
and kept misfiring.

My "Check Engine" light finally came on and my code reader indicated a
misfire in the #8 cylinder.

This morning, when I pulled the #8 spark plug boot off, I saw that the
plug was SOAKING WET with coolant! The hole for the spark plug was so
full that coolant ran out of it when I inserted the spark plug wrench!

So, I am assuming that there has been a massive failure somewhere.

I checked the torque on all of the intake bolts...they were perfectly
within specifications (20 foot-pounds).

BUT WHAT DO YOU THINK HAPPENED?  Could the manifold be OK and the block
be cracked? Or is this a case of yet another intake failure? I have
NEVER allowed my engine to overheat. Temp has ALWAYS read on the cool
side of the normal range.

I did NOT use Permatex on the intake manifold, per the
instructions...should I re-think that? Or should I assume that the
intake is cracked or warped? Either way, it looks like I will have to
pull the intake and see.

I am SO sick and tired of this 4.6L engine leaking coolant every time I
turn around!!!