Chevy S-10 Truck Coolant Temperature Low

1992 Chevy S10 4.3L. Repairs: Replaced Thermostat, back flush heater core, drained radiator and added new antifreeze. Question = The engine will not heat up past 140-degrees.

Answer:
If the coolant level is fine, it is possible that the thermostat and/or flush fixed your problem, but you have an air pocket it the system and was not bled properly. This would give the same condition, so you would think it is not fixed. A way to tell is listen for a water rushing sound in the dash as you do a few hard accelerations. The noise is air rushing through the heater core.

If the engine will no heat up, and i assume the correct temperature thermostat is installed, then your truck could have a possible internal engine problem or just a bad coolant temperature sensor.

You did not say if you are getting good heat out of the vents or not. If you are, then the gauge reading is incorrect. It could just be a bad sensor or a wiring problem at the connector. A plugged radiator would give the opposite condition- engine would overheat.

Since you flushed the heater core, i guess you are not getting good heat. If that is the case, then the sensor is fine and the engine actually is not heating up. A cause for this could be a blown head gasket. This would cause compression to be pumped into the cooling system. Air pockets in the coolant would get into the core and around the temperature sensor and cause your condition. The sensor cannot read air, and the core cannot transfer heat from air- only from a liquid. With the engine running see if there are a lot of bubbles in the coolant.

Question:
Can't get truck to go in gear. Lost clutch won't. Change gear wile running. But got clutch pressure slave cylinder pushes the fork on trans forward what do. U think is wrong can some one help.

Answer:
If the fork is moving, then you must have an internal problem in the transmission. Possibly a broken shaft or synchronizer. You are going to have the remove the transmission and take it apart to look for the failure. There is nothing external that can cause the problem you are having in your S-10 truck.