Heater Problems
raabooj
10-17-2009, 03:56 PM
I have a 1987 Chevrolet Silverado with a 468 BB. The upper radiator hose is hot, but the lower one is cold. The heater hoses are also cold. I put a new thermostat in it and also flushed out the system with a garden hose and there are no restrictions. Any solutions to this problem?
777stickman
10-17-2009, 05:41 PM
Welcome to AF.
Please tell us what indications you had to ask this question. Is it overheating? What have you replaced prior to this issue?
All the info you can give us will help us help you.
Please tell us what indications you had to ask this question. Is it overheating? What have you replaced prior to this issue?
All the info you can give us will help us help you.
jyount
10-25-2009, 10:48 PM
I have a 1987 Chevrolet Silverado with a 468 BB. The upper radiator hose is hot, but the lower one is cold. The heater hoses are also cold. I put a new thermostat in it and also flushed out the system with a garden hose and there are no restrictions. Any solutions to this problem?
If the upper is hot, ie thermostat is open, and the lower hose is cold, that can only mean one thing, the radiator is stopped up.
If the upper is hot, ie thermostat is open, and the lower hose is cold, that can only mean one thing, the radiator is stopped up.
j cAT
10-26-2009, 08:21 AM
If the upper is hot, ie thermostat is open, and the lower hose is cold, that can only mean one thing, the radiator is stopped up.
this problem can be caused by other failures...air/exhaust gases traped inthe coolant system, water pump corroded, fan belt missing.
I would with the engine cold remove the radiator cap and continue to run engine heater set to max heat..as the engine warms you must see flow inside the radiator,,if not you must find out why...start by removing the thermostat then recheck for flow...if the coolant bubbles as its warming up then you got the head gasket/head cracked etc...
this problem can be caused by other failures...air/exhaust gases traped inthe coolant system, water pump corroded, fan belt missing.
I would with the engine cold remove the radiator cap and continue to run engine heater set to max heat..as the engine warms you must see flow inside the radiator,,if not you must find out why...start by removing the thermostat then recheck for flow...if the coolant bubbles as its warming up then you got the head gasket/head cracked etc...
kahjdh
10-26-2009, 11:27 AM
Seems like a cirulation issue, If you flushed everything and there is no heat to the heater hoses I would look at the water pump. Those hoses should heat up as the engine heats up.
Tdragone
10-26-2009, 08:57 PM
I'm with Jcat on an issue..
In MY experience this is because there is a huge air bubble in the heater core.
Try his recommendation of cold engine... remove radiator cap and start engine. Let it idle and get warm and hopefully with an unpressurized system the heater core will 'burp' itself.
If this doesn't work.. with a cold engine remove thermostat then use vice grips to pinch off the the inlet/outlet hoses for the heater core. un-fasten whichever end of the outlet heater core return hose is higher.. then undo the intake vice grip allowing water pressure IN TO the heater core. Lastly remove the vice grip on the outlet side and the air should begin to evacuate slowly.
Good Luck.
In MY experience this is because there is a huge air bubble in the heater core.
Try his recommendation of cold engine... remove radiator cap and start engine. Let it idle and get warm and hopefully with an unpressurized system the heater core will 'burp' itself.
If this doesn't work.. with a cold engine remove thermostat then use vice grips to pinch off the the inlet/outlet hoses for the heater core. un-fasten whichever end of the outlet heater core return hose is higher.. then undo the intake vice grip allowing water pressure IN TO the heater core. Lastly remove the vice grip on the outlet side and the air should begin to evacuate slowly.
Good Luck.
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