Blows out plenty of hot air when moving, but cools off very fast at idle speeds. The radiator is hot enough to burn you at the top hose and the right side, but cold cold on the left and at the bottom side. Both of the heater hoses are hot, too. Could this be an air pocket trapped somewhere? Maybe in the engine block? The truck is not overheating at all. I know the heater core is good, I flushed it out and you can blow thru it. I have replaced the water pump, the thermostat, and the radiator. Still having the same problem. Could the thermostat be installed backwards? How could I tell?
2006-12-16 07:26:47 · 6 answers · asked by kritter0101 2 in Cars & Transportation ➔ Maintenance & Repairs
It started all at once, after the antifreeze overflow jug on the side of the radiator got empty. Could it have sucked in too much air? I refilled it, and now it gets barely warm at an idle, but the heater is really hot while driving. I have probably put 2 - 2 1/2 gallons new antifreeze and water in it since I replaced the parts.
2006-12-16 10:10:24 · update #1
I doubt the heater core is the culprit in this case. I say that because the radiator itself is hot on one side, but cold on the other side and the bottom.
With given information, I would say definitely a flow problem. The thermostat should be installed with the longer side with the spring towards the engine, the short side towards the radiator. You can also put it in a pot of water along with a thermostat and see what temperature it opens at to see if it is working as it should (should be around 185 or 190 degrees).
Possibilities could also include bad water pump, or bad radiator (even though they're new, they do on rare ocassion come out of the box bad), collapsed hose (can be collapsed inside while still looking round on the outside).
Did this problem start after you replaced something due to a failure or did you replace the parts trying to fix this problem?
2006-12-16 08:15:52 · answer #1 · answered by Mark B 6 · 0⤊ 0⤋
You might have a partially blocked heater core. You would be able to blow through it but not all of the surface area could be getting warm. While you are not moving, the radiator may be cooling it enough. If the thermostat was in backwards you would be overheating because it would never open. It sounds like the heater core is the last thing you haven't changed. Check there. Good luck
2006-12-16 15:33:47 · answer #2 · answered by Josh P 3 · 0⤊ 0⤋
i would get it in somewhere, just sounds like the thermostat is not working right, or the new water pump is not working correct as well. Have you checked your heater core?
2006-12-16 15:32:40 · answer #3 · answered by bryan_w74 2 · 0⤊ 0⤋
Vacuum not strong enough to pull on heater control diaphragm at idle. Its design to always be shut unless vacuum is applied.
2006-12-16 15:29:54 · answer #4 · answered by Anonymous · 1⤊ 0⤋
Suspect the heater blower motor has quit.
2006-12-16 15:28:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋
My guess...low coolant level.
Check it when it's cooled down.
2006-12-16 15:30:38 · answer #6 · answered by Mr. KnowItAll 7 · 0⤊ 0⤋