720 got hot ,oil in coolant ,is the head gasket blown?

[ex viking]

Hello All.  Driving home My pickups temp started to rise past normal slowly. I made it home with out it getting to top of the temp gauge only about 3/4 up. I opened the hood coolant was coming out of the water pump gasket by the timing mark. I pulled the water pump and found oil in the coolant, no coolant in the oil. Is the head gasket is blown?

[datzenmike]

The Z24 has a tendency to blow the head gasket every 100K miles. The preventative 'cure' is to loosen each head bolt one at a time and right away torque to 60 ft. lbs. You can do them in any order just don't loosen more than one at a time. Do this on a dead cold engine. It's recommended by Nissan, to do this every tune up but once a year is plenty.

 

 

I doubt it's your head gasket but re-torquing is very cheap insurance.

 

While the coolant is out, replace the thermostat. Get a $12 one not a $3 one from WallMart. Your thermostat is 30 years old and if there is ever an unexplained overheating just replace it. This never hurts and can save you a jug of new antifreeze and a tow next week. 

 

Take a look on the under side of the water pump just behind the pulley. There is a weeping hole to release water if the internal seal has failed. Only if there is wetness or signs of leaking should you place the pump. The stock pump is far better than the crappy rebuilt ones on the market so replace at your own risk. Replace the pump gasket. Refill with good quality coolant/anti freeze (if yours isn't) and road test.