Coolant System

I HAVE A 1998 PONTIAC GRAND AM AND I AM HAVING PROBLEMS WITH THE COOLANT SYSTEM IT IS NOT BUILDING UP PRESSURE CAN RELEASE CAP AND NOTHING HAPPENS EVEN WHEN IT IS HOT AND DOES NOT ALLOW RESOVOR IN PLASTIC TANK TO FILL, HAVE CHANGED RADIATOR CAP AND WAS WANTING TO KNOW IF THE THERMOSTAT OR WATER PUMP COULD BE THE CAUSE OF THIS? WOULD APPRECIATE ANY HELP YOU CAN BE, CONSIDERING WHERE THE WATER PUMP IS LOCATED WOULD BE A MAJOR JOB TO CHANGE. JUST WANTED TO GET SOME OPPINIONS FIRST. I ASK FRIENDS AND NONE OF THEM TELL ME THE SAME THING. THANKS FOR YOU HELP :banghead:

Welcome to AF, first what exactly is the problem, overheating, loss of coolant, no heat in car? Also always post the engine type/size.

Welcome to AF, first what exactly is the problem, overheating, loss of coolant, no heat in car? Also always post the engine type/size.

Thank you for replying to my post. Guess it would be helpful if I gave engine size haha, its a 4 cylinder 2.4 and its not over heating, a friend of mine changed the heater core,since then I have this problem, ( I have the plastic resevoir it does not hold fluid now) where it shows to fill to there is no fluid in there the overflow is full but not fluid in resovoir for radiator. And was told by another friend that it is not building pressure. Has not over heated but runs hotter than normal not much but some.

Ok so you are loosing coolant, you fill the jar and it disappears, is this what is happening?

Ok so you are loosing coolant, you fill the jar and it disappears, is this what is happening?


Yes that is exactly what happens.

System should be pressure tested for external leaks, if none visible, possible head gasket problem which can be checked with a coolant test kit designed for testing for hd gasket leaks.