A/C - Thumping From Dash On Heat With Blower On High
TSB 08-5-903/17/08
THUMPING/LOUD FLUTTER - BEHIND DASH IN
DEFROST MODE - LACK OF AIRFLOW TO FLOOR -
MANUAL A/C ONLY
FORD:
2006-2008 Explorer
2007-2008 Explorer Sport Trac
MERCURY:
2006-2008 Mountaineer
This article supersedes TSB 07-8-2 and 06-7-9 to update the vehicle model years, Issue and Service Procedure.
ISSUE
Some 2006-2008 Explorer 4dr and Mountaineer and 2007-2008 Explorer Sport Trac vehicles equipped with manual A/C may exhibit a thumping or loud flutter behind dash when in floor mode with full heat selected and on high blower setting. This condition tends to occur in colder ambient temperatures and the vehicle at operating temperature. This concern is caused by high blower air pressure coming over the blend door.
ACTION
Follow the Service Procedure steps to correct the condition by replacing the blend door.
SERVICE PROCEDURE
NOTE
EVACUATION OF A/C AND COOLING SYSTEMS ARE NOT REQUIRED.
1. Start the vehicle and set the climate controls to floor position, full heat, and max fan speed positions.
2. While driving down the road, open the passenger side window a 1/4".
a. If a flutter/slap noise is heard, go to Step 3.
b. If not, do not continue with the TSB and perform normal diagnostics.
3. Move the A/C setting to full cold before turning off the engine.
4. Remove the instrument panel, refer to Workshop Manual (WSM), Section 501-12.
5. Remove seven (7) screws from plenum in order. (Figure 1)
6. Separate case slightly. (Figure 2 - Side View)
NOTE
THERE WILL BE VERY LITTLE SEPARATION.
7. Remove right side of blend door from the boss in the case. (Figure 2 - Top View)
8. On 2006 Explorer and Mountaineer only, inspect the blend door spring. If the spring is an old style spring replace it with the new J hook spring. (Figure 3)
NOTE
ON ALL OTHER APPLICATIONS, THE SPRING DOES NOT NEED TO BE REPLACED.
9. Drill five (5)1/2" (13 mm) hole as shown into the blend door. Make sure that the holes edges are smooth with no burrs after drilling. (Figure 4)
10. Place the door back into the housing. Put the left hand side in first. You may have to apply a modest amount of pressure to get the right side of the door to seat. (Figure 5)
11. Set the other end of the spring into the housing (Figure 6)
12. Replace seven (7) screws in the plenum in same order. (Figure 1)
13. On 2006 Explorer and Mountaineer which require the new spring, takes two (2) pieces of the sectioned mastic and stack them next to the spring boss. (Figure 7)
14. Function the door vigorously by hand and recheck the door movement.
15. Install instrument panel, refer to WSM, Section 501-12.
Parts Block
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATION DESCRIPTION TIME
080509A 2006-2008 3.0 Hrs.
Explorer/Mountaineer,
2007-2008 Explorer Sport
Trac With Manual
Temperature Control: Drill
5 Holes In The Blend
Door, Includes Time To
Remove And Install
Instrument Panel,
Transfer/Replace Spring If
Necessary And, Road Test
To Verify Concern (Do Not
Use With 04320A,
0432AZR, 04320B,
04320BZR, 18476A,
19616A, 19616B, 19616C,
19616D, 19700A,
19700A13, 19700A15,
19700D, 19700D4,
19700D5, 19700D6,
19700D7)
DEALER CODING
CONDITION
BASIC PART NO. CODE
18A361 34
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