Heating issue ?!
Have you scanned your engine computer? If your thermostat is stuck open, it will set Diagnostic Trouble Code (DTC) P0125 or P0128 These codes indicate that the Engine Coolant Temperature (ECT) sensor or the Cylinder Head Temperature (CHT) sensor did not reach operating temperature within a calibrated amount of time after engine start-up. These monitors have to fail on two CONSECUTIVE engine start-ups before they will turn the check engine light on. So if you start it cold, then shut it off and start it when it is still partially warmed up the next time, it would never turn the light on because the monitor does not run on a partially warm engine. However, they will store a fault code in continuous memory on the FIRST failure. So, your check engine light may or may not be on if these codes are set. If one or both of these codes are set, then your thermostat is the most likely suspect.
Other than this, the best way to verify proper cooling system operation is with an infrared thermometer. These can be purchaced at most parts outlets for around $65 or less. (AutoZone has one listed on their web site for $54.99 Part Number: MSC52224ASP )
This is a lot less than one hour's worth of diagnostic time in most shops....And you can use the thing for many other purposes.
You can point it at your thermostat housing and while doing this, feel the upper radiator hose with your hand. The upper radiator hose should not begin to feel warm until the thermostat housing gets up to around 190 Deg. F. At 195 Deg, F, the upper radiator hose should feel VERY hot. You can also point the infrared at the radiator tank near where the upper hose connects to verify this. If the hose (or the radiator tank) gets warm too soon, the thermostat is stuck open.
Nov 16, 2011 |
2003 Ford Escape