Poor heater performance

ROGERE53

MEMBER
1999 FORD EXPEDITION
5.7L
V8
AWD
AUTOMATIC
187,000 MILES

My SUV listed above has had a problem for two years now with barely luke warm heat in the winter. This is occurring at the front, middle, and rear heat vents. I replaced the blend door two years ago (which was broken) but I still barely get any heat. According to the temperature gauge, my engine temperature is running consistently, but the heater hoses are hardly warm to the touch. The engine was replaced with a slightly newer one last summer so I do not think it is a water pump issue (but maybe I have had two worn out pumps?). I have read some blogs which say that there is a heater control valve, but other blogs say they no longer exist. If there is a heater control valve, where is it located?

3 Replies

HMAC300

MECHANIC
48,601 POSTS

Check thermostat it should be a 195 temperature in it not anything lower. Then check radiator for cold spots or loose fins. If hoses are not getting hot then it may be a thermostat problem more than likely. Ford used to use water valves but like everyone else has gone to actuators.

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Monday, December 12th, 2016 AT 3:54 PM

ROGERE53

MEMBER
2 POSTS

The thermostat is a 195 degree unit and appears to be working fine. The hoses to and from the radiator get but the hoses in and out of the heater core only get warm.

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Monday, December 12th, 2016 AT 4:25 PM

HMAC300

MECHANIC
48,601 POSTS

Check for a bad radiator cap then when it is found to be good get engine warm have coolant full then rev to about 2500 rpm for a couple of minutes then return to idle and recheck coolant bottle when cool if low add fluid. DO NOT REMOVE RADIATOR CAP WHEN HOT. If that fails then try jacking up truck or if you have air bleeds in engine/cooling system try bleeding air through bleeds.

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Monday, December 12th, 2016 AT 4:45 PM