hi temperature up to working

My 96 blazer periodically, when I first run it in the morning, goes all the way up to about 230-240 degrees, the check gauges lights come on (on the verge of overheating??) then the thermostate finally opens up (aftert a bit of anxious moments by myself) and goes back to normal operating temperature of about 180..

Ironically, it does not do this everytime..and has not done it since the cooler days of last spring..just starting again after the summer months... takes about four miles at 30mph less to get to the high temperature...usually does not do it on the way home, even after the balzer has been a lot all day long..

I had the thermostate replaced last January, and again in March thinking we had a bogus thermostat...

Thank you for your help..

R

I had the same problem with my old 96 blazer, however, mine did not go high enough to make the "check gages" light come on.

Like you my mechanic changed the thermostat but it did not help. We could not see any other problem so a month later at my urging, he replaced the thermostat AGAIN with a genuime GM stat.

The problem went away.

Also make sure the system is clean and that the stat is not upside-down (no offense)