'95 Dodge Spirit, started overheating 2-years ago. Verified gauge with IR scan thermocouple, runnning 225F+, never did before. Went through electric fan troubleshooting, replaced radiator, cap, upper and lower radiator hose, the radiator, the belts, the tensioner, the water pump, the works. Did not have benefit of PRESSURE TESTER PUMP which would have saved my butt down here.
The beneath the V6 manifold lower radiator hose transfer tube had a leak. Very small. It would force coolant out. Maybe a cup or so but no more than that in hot weather. Doesn't sound like much does it? The termperature gauge though differently. It would swing over to near "H". The coolant recovery system DOES NOT WORK if there is the tiniest leak in the system. I guess the vacuum is satisfied easier leaking backward through a small pinhole than it is by working against a radiator cap spring.
One LOUSY cup of water, that's all it took. It must have cavitated the pump's ability to suck water. When my aluminum engine heat gauge goes to near "H" it bothers me, a lot.
To top it off, not even genuine Alumaseal® helped the leak issue. It was tiny. it was more than tiny.
But never again am I going to get sucked into wasting many hours and a lot of money trying to outsmart a radiator pressure test gauge. I'm not foolish - the nearest one is maybe a thousand mile round trip and you can bet your burro I've got a Stant Pressure Tester on order, a twelve hundred mile round trip. The eystem will get tested to 15 lbs. If it loses pressure, if I see dampness then I'll get to work.
I've NEVER seen a motor vehicle with that level of sensitivity to a missing cup of water. Before you fume, read, what I have replaced. There are no "missing links". Until that pinprick size hole in the tube was brazed up the temperature acted as nuts as Norman Bates.
Maybe this bitter lesson can help someone else with a K car with 3.0 V6 engine.