Just finished installing a new water pump, thermostat and bypass hose on my 1996 Dodge RAM 1500. The actual culprit of the leak was that the bypass hose swelled to the point that the clamp cut into it, on the engine connection side (almost did not pull it, good thing that I did!!) Since I had to remove it all I might as well replace what might need replacing
During the process I snapped off the terminal for the coolant temp sending unit so I had to replace it
I decided to run the Prestone Cleaner through the system to give it a good clean out, so just that and water, no leaks! Yeah!
But now my temp guage spikes to the last zero in 200 (so 230 degrees) on the guage and just sits there. Ran the truck for about 2 hours and it never went down or up. I even squeezed the upper radiator hose thinking I had a trapped air bubble and still it will not go down.
Before the leak, the temp guage went through the normal operating range of up to 220, thermo would open and it would drop to 190 or so.
Is it possible that the new coolant sending unit is bad?
I did notice that the upper radiator hose does get hot as normal but the lower hose barely gets warm. Is that normal? Does it mean that it is cooling properly?