Hello everybody,

My 2001 blazer has developed a few quirks. First of all, the temperature gage reads all over the place, especially in traffic. It will go up high enough for the check gauges light to come on and then fall below normal running temp seconds later. The other thing that I have noticed is sometimes the heat doesn't work. This seems more random but does tend to happen more at speeds below 45. I have done some reading and I heard similar conditions can be caused by air in the coolant system. Does this seem right or is it something worst?

Thank you,

Kyle

 

First things first, have you checked the coolant level both in the reservoir and the radiator?

 

Coolant level, thermostat, water pump, lower intake manifold gasket are all common reasons that cause the problem you identified. Air in the system is not. If you are getting close to overheating you need to be very careful, a radiator pressure test may be the best tool to direct you to the source of the problem if you can't identify it visually.

 

As GunsOfNavarone stated:all are possible-but start with the pressure test-but this may not be the solution either as some symptoms don't present themselves unless expansion & contraction take place (hot & cold cycling)