the car warms up, i turn the heat on or i start driving and get onto expressway going like 60-70 mph and the temp. gauge starts dropping to cold..? is the engine actually dropping in temp. or is my gauge messed up?

 

sounds like your thermostat is broken. Does your car take a while to warm up?

The heater unit uses radiator fluid. When you turn it on, you allow the fluid to flow through the unit, which allows for additional heat transfer.

Same thing with the expressway, you are moving more air over the radiator, which allows for more heat transfer.

I say your thermostate is broken because it has failed, and is now in the full open position all the time. When it is working properly, it will close itself, restricting the flow of fluid within the block, and allowing from proper engine temperatures.

 

its a 92 Integra LS, it takes about 10-15minutes to warm up, 15 min. to warm up all the way, you def. right i figured that was it, now that pc is located in front of the block but towards the left right? like kinda near the trannie?

 

id say the thermostat.

 

where is the thermostat located on my 92 integra LS?

 

its on the rear of the engine...where the lower radiator hose goes.