A/C - Abnormal Heater Performance at Idle
TSB: 07-001/062006 MX-5
ABNORMAL HEATER PERFORMANCE AT IDLE
APPLICABLE MODEL(S)/VINS
2006 MX-5 vehicles with VINs lower than JM1 NC**** 60 111258 (produced before December 22, 2005)
DESCRIPTION
Some customers that park their vehicle on a decline or brake hard during cold engine conditions may experience abnormal heater performance at idle. This condition can be the result of air moving up from the radiator sub-tank through the thermostat housing and becoming trapped in the heater core and/or its supply lines.
To prevent this condition from occurring, the shape of the hose between the radiator sub-tank and the thermostat has been changed. Customers having this concern should have their vehicle repaired using the following repair procedure.
REPAIR PROCEDURE
WARNING:
If the engine is very hot and the water hose is compressed, be careful when removing the cooling system cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes before proceeding with any repair.
1. Verify customer concern.
2. Remove the water hose.
3. Align each mark and fit a modified water hose.
4. Using a clip, secure the modified water hose, heater hose and power steering hose together.
5. Refill the coolant into the coolant reserve tank up to the F mark on the tank.
6. Install the cooling system cap.
CAUTION:
^ During the bleeding procedures, if the water temperature gauge rises too high, stop the engine and decrease the water temperature to prevent overheating. Then, verify the malfunctioning part and repair or replace it.
^ During the bleeding procedures, if the engine coolant level in the coolant reserve tank is below the L mark during engine coolant air bleeding operation, stop the engine, and after the engine coolant temperature decreases, add engine coolant. Then, resume the engine coolant air bleeding operation.
7. Perform the bleeding procedure as follows to ensure all trapped air is bled from the cooling system.
A. Start the engine and warm up the engine by idling.ne by idling.
B. After the engine warms up, perform the following steps. At this time, be careful of the coolant temperature to prevent overheating.
a. Run the engine at approx. 2,500 RPM for 5 minutes.
b. Run the engine at approx. 3,000 RPM for 5 seconds, then at idle for 5 seconds.
c. Repeat step (b) 4-5 times.
C. Stop the engine, and inspect the coolant level after the coolant temperature decreases. If it is low, repeat steps 4-10.
8. Verify repair.
PART(S) INFORMATION
WARRANTY INFORMATION
NOTE:
^ This warranty information applies only to verified customer complaints on vehicles eligible for warranty repair. Refer to the Warranty Wizard for warranty term information.
^ Additional diagnostic time cannot be claimed for this repair.
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