I have a 1998 Chevy k1500 with the 5.7l. I have had no heat whatsoever and my coolant only getting to about 140°f... I have already replaced the thermostat, radiator, water pump, and heater core, I have practically brand new hoses, I buy premixed 50/50 coolant, and no leaks.. anyone have a solution??? I'm stumped

 

Replace to thermostat again. Install a 190 deg. Because it's new dosen't mean it is good

 

Feel your heater hose lines to make sure they are hot as well. Maybe air in the system needs to be purged?

 

There is a 195 degree thermostat in there currently, and both upper, and lower hoses are the same temp down to a few degrees

 

did you change the rad cap? The system needs to hold pressure to reach proper temperature.

Also no heat can be related to cabin problems rather than cooling system, like a stuck temperature door.

 

The system has plenty of pressure, but what problems are cabin related?

 

If your blend door actuator is stuck or bad it will not change from cold air to hot air or anything in between. The blend door may also be broken.

 

Would that affect it not getting up to temp. It won't go past 140 degrees after 45 ish minutes of driving, and I tried blocking the radiator off.

 

No that should not not affect it getting to temp. Are you sure your gauge is correct?

 

Yes I'm sure the gauge is correct, I took a laser temperature gun and got about 140 at the thermostat housing