Help Please 1996 S-10 Blazer Low Engine Heat

My Blazer has had a problem for the last couple of years with a lack of heat. Last fall I power flushed my cooling system and replaced the thermostat with a new 195 degree t-stat. This took care of most of the in truck heat problem. It still is not what I would call great heat but it is liveable here in Milwaukee. I am only able to get about 140 degrees on the gauge anytime of the year unless I am pulling my boat. Those times it get up to about 170 degrees. Otherwise, the heat sucks.

Any ideas as to what I should start looking at?
Should I try flushing the system a couple of times and replaceing the thermostat with a GM stat???

Help

Thanks in advance.
Greg

you might want to recheck your thermostat there might be a piece of crap stuck in the thermostat holding it open and not slowing the flow of coolant and not letting the engine heat up. I would not flush the system if it is staying cool that means there is no blockage in the system. Also does it heat up to peak temp fast or slow, fast would say a possible guage problem also, and slow would be a good sign of a thermostat problem.

It takes about 10-12 minutes to heat up if I let it idle. I am going to try another thermostat to see if it helps.

Gregg

I dont think the thermostat is going to help, I have had that issue on two engines now. My last one blew up and always ran at about 160 under a thermal gun. It just would not get hotter, I went through 3 thermostats of various brands and it didnt help. I now have a new setup, new engine with new radiator, original heater core though, same thing, it runs at about 160-170. I have no idea how or why it defies normal rules. Just wanted to let you know, your not the only one in the world with this issue on their mind.

I had purchased my blazer recently and had the same problem. First thing I did was remove all the dex cool from the system and flush it out about 5 times to make sure it was all gone then I put in regular green antifreeze. I changed my thermostat and I started to get heat again. I flushed it out again about a month later to make sure it was not jelling up on me.