So I have been having this sneaky suspicion that my thermostat is stuck open. What peaked my interest was that the truck has been having a hard time heating up at idle when outside temps are under 35 F or so. What happens is I will start the truck up on an icy morning and let it idle for 20 minutes or so. When I check my scan tool the coolant is only at 160 F. Now I never thought this was a problem because after I get it out and start driving the coolant temp reaches about 200-204 F and is stable.
Over the past few days I have noticed when I downshift to 3rd and pass the temp drops pretty far. And tonight I went to idle it again and it did the same thing...never got up above 160 F or so.
But here is what I think is the damning evidence. After idling the truck tonight I waited till the temp got to 160 F again on my scan tool. Then I took the radiator cap off and took a temp reading using a probe thermometer. It read 150 F! What the heck? I think this means only one thing. The coolant in the radiator and engine are one complete circuit and the thermostat is open. Correct? Shouldn't the coolant stay cool until the thermostat opens at about 180F? Or is this normal for our vehicles. It would seem that the thermostat is not closing all the way yet opens enough to keep the engine cool and not go over 210 F.
Edit: Screw it. Just got new upper and lower radiator hoses, radiator cap, and ACDelco 15-11006 Thermostat for a total of $80. Im gonna fix this thing for good.
Over the past few days I have noticed when I downshift to 3rd and pass the temp drops pretty far. And tonight I went to idle it again and it did the same thing...never got up above 160 F or so.
But here is what I think is the damning evidence. After idling the truck tonight I waited till the temp got to 160 F again on my scan tool. Then I took the radiator cap off and took a temp reading using a probe thermometer. It read 150 F! What the heck? I think this means only one thing. The coolant in the radiator and engine are one complete circuit and the thermostat is open. Correct? Shouldn't the coolant stay cool until the thermostat opens at about 180F? Or is this normal for our vehicles. It would seem that the thermostat is not closing all the way yet opens enough to keep the engine cool and not go over 210 F.
Edit: Screw it. Just got new upper and lower radiator hoses, radiator cap, and ACDelco 15-11006 Thermostat for a total of $80. Im gonna fix this thing for good.