Hi, I have a 2000 b3000 it has 124,000 miles. Anyways I will explain my problem. while im driving under normal conditions , I experience flucuation of the water temp gauge it will normally read right in the middle, but occasionally it drops completly off to dead cold on the gauge. along with this issue , heater temp varies erraticly. Over flow tank also overflows from time to time. Water temp gauge never goes above 3/4 .
any help appreciated THX , JOHN


I have replaced:
thermostat 3 times
Radiator cap
P.S I had water system flushed prior to symptoms

 

Does the radiator fan ever stop or is it always on? It should stop blowing when the temperature drops below a set point.

Coolant flow could be affected by internally deteriorating coolant hoses.