We purchased this Ford Explorer in May of 2008. The owner stated that the intake manifold gasket was bad. He had to fill the radiator after every 15 miles of driving. He told us that he had someone look at it.
It was obvious that water was mixing with the oil, and when we filled the radiator with water and started the SUV, it was blowing water out the tailpipe and dripping from below the engine.
After getting the vehicle back to the garage, we removed the heads, and found that the passenger side head had been severely cracked.