Chevrolet Repair: 1984 chevy blazer 2.8, chevy blazer, coolant level

Question
temperature gauge has a tendency to go almost redline and then drops to normal every time I drive it. I have since changed the thermostat and the water pump. any help is very useful?

Answer
The coolant system has to pressure up to about 30 psi to open the thermostat. I think if your thermostat is new and the water pump is new the most common problem is the intake gaskets may be leaking. Is your coolant level low about every week because that would tell me you have a leak somewhere. If the gaskets are good and your not leaking anywhere you temperature sending unit may be bad. If none of these are the case then it may be as bad as a head gasket.