So i have an 02 mazda b2300, 5 speed, 2wd. I am curious about a wierd issue the truck has. It stays at normal operating temps most of the time (i normally shift between 2500 to 3k rpms) but if it take it over 3500 rpms the temp gauge starts to read the engine cooling all the way to stone cold but then quickly rises back to reading normal when i let off. I do have a slight coolant leak ( still trying to find that bastard) that seems to go down the drivers side of the engine near the oil filter ( dont know if that helps solve the titled problem p.s not coolant in oil). Its just super strange tk me and wanna get insight.

 

Can you reproduce this when just parked?
Obviously the engine coolant is not actually cooling down so there must be something electrical going on. With someone helping you try the wiggle test. As it's running start to wiggle the wires to the temp sender and see if the gauge moves.

 

@Rock304 While parked itll do it just more at 4200 rpm while driving it starts at 3500 ill check the temp sensor wires Thursday when im off from my 2nd job

 

Do you have a mechanical fan cooling fan or electric fan?

If mechanical could be fan clutch is locked full time

If electric could be its running more than it should