95 Caravan Heater

Recently I have been having problems with my heater. It gets kinda warm (not hot like usual) then goes cold about 30 seconds later. This continues the entire time the car is running. My dad told me to check my coolant, I did and it was a bit low so I added what was needed.

This morning my check guage light came on (around 60 mph) and the guage showed the van was running hot, the van sort of jerked and then the guage dropped down to normal again. It was only showing hot for like 5 seconds. This happened only after being driven about 5 min after being parked at work all night (temp was about 3 above zero).

I have not overheated as of yet. I really don't know anything about cars. I did notice that when the car is turned off it seems to gurgle a bit, not sure if it has done that before or if its normal.

Any ideas?

you don't say how many miles or yr of veh, however look at thermostat or inline valve in one of the heater hoses, valve opens and closes as heater is turned off/on from inside veh....may not be on this particular veh

Its a 1995 and it has a little over 100000 miles on it.