Is there a cooling purge/bleeding procedure for my new to me 1997 Blazer with V6 4.3?
The truck had poor heat, was only getting warm and the temp gauge didn’t work. So I replaced the thermostat and temperature switch. The truck now has great heat and temp gauge reads, but when driving it now the temp gauge goes up to about 260 degrees (check gauges light comes on) for a moment and then drops back to about 215. At an idle temp will stay about 215 it only goes up to 260 when driving it for the first ½ mile. I was hoping it was just an air pocket in the cooling system.

 

Raise the front end, right side slightly higher. With radiator cap off, run to operating temp adding coolant as necessary. Let it cool down, repeat the procedure. Replace the cap with a 16# Stant lever valve cap. Let us know if the problem continues.

 

Takes a bit of time, but I have always had good success with this method.

1. Jack up the front end holding the passenger side slightly higher (one notch on a jack stand) than the driver side.
2. With the radiator cap off, run the engine until it reaches normal operating temperature.
3. Allow the engine to cool off.
4. Repeat 3 or 4 times
   

Throughout all of this, you need to keep the radiator full. As the coolant heats up and expands, you may spill some coolant out.

When you are all said and done, make sure that the radiator cap is good (replace it if you have never done so recently), the overflow tube will flow coolant freely, and fill the overflow up to just above the cold level when the engine is cold or just above the hot level when the engine is hot.

I get a phone call and get undercut! LOL

 

The early bird gets the worm, but the second mouse gets the cheese.

 

Thanks I'll give it a shot