My temperature gauge on my Mazda B2000 only seems to be responding when it is overheated.

After driving a while the temperature gauge doesn't move, then I climb a hill or go under load and when I stop I'm loosing water out the overflow and steam everwhere.

I am leaking oil since I recently rebuilt the top end. It looks like from the heads again. I didn't replace the thermostat.

This weekend I guess I have to strip the engine, but do I need a water pump, or what? The oil is leaking at the front over top the water pump, could I have damaged the seal? Is the water pump lubed with oil? Why am I blowing steam and my temperature guage rising only in extremes?

By the way there is no water in the oil.

When it is warmed up it is starting to miss fire or the rpms are way down and it chugs. (timing was done a couple weeks ago)

Checked the spark plugs they were clean but oil on the housing of 1 and 2. I think the plugs are shorting out from the oil.

when they manufacture the water pumps they have a hole drilled into the pump on the buttom just past the pully, this is to stop water getting to the seal check to see if there is a drip coming from there if not pump is fine. Another way to check while the engine is running remove the radiator cap and watch to see if the water is flowing also rev the engine and watch the water level it should drop this is an indication that the pump is working.Your thermostat sounds like it is stuck open check and replace!

First replace the thermostat. Then run a compression check as you may have a head gasket leak. Are the plugs spotless in 1 & 2? They should have a light coat of deposits on them like the other two cylinders. If not you are probably getting water on them and combustion gases in the water as it warms up. Some of the parts stores sell a test kit for checking for combustion gases in the radiator. If the compression is down in two adjacent cylinders its usually the head gasket. Good luck.