Coolant loss from overflow tank

[Jay57nj]

Hi All:

My '98 Mounty 5.0 is loosing coolant at the rate of one quart a week in about 250 miles. Truck just turned 160K, and my good friend who is an ASE Tech and Technical School instructor has done alot of work on it lately.

It had a coolant leak which he diagnosed as a bad thermostat housing which was replaced, along with the thermostat and bypass hose, and upper and lower radiatior hoses. No leaks for about 2 weeks, but now have the coolant smell again, along with diminished coolant level in the overflow.

Any suggestions on where to start the search? It was recently tuned as well with new plugs and wires and a serp belt. Oil level is good with no apparent mixing.

Thanks in advance for any advice.

 

[Xplorer82]

have him (or you) check the weep hole on the back of the water pump. that was my culprit. other things to check is intake gaskets, heater core and i believe the heater control valves on the explorers tend to leak.