Could it be the problem below:
TSB
08-2-10 4.6L MANUAL TRANSMISSION - SEPARATOR PLATE BUZZ - BUILT BEFORE 12/13/2007
Publication Date: January 22, 2008
FORD: 2005-2008 Mustang
ISSUE:
Some 2005-2008 Mustang vehicles built before 12/13/2007 and equipped with a 4.6L engine and manual transmission, may exhibit an oil-canning or exhaust rattle/buzz around 2000 - 2500 RPM during the first few minutes of driving after a cold start. The sound goes away after the car warms up.
ACTION:
The concern may be caused by the separator plate, between the rear face of the block and the transmission housing, vibrating and/or contacting the flywheel. Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
Remove transmission per Workshop Manual (WSM), Section 308-03B.
Pry separator plate from rear face of block alignment dowels, slide out from between block and flywheel, and replace with new service part.
Install transmission per WSM, Section 308-03B.
NOTE: INSTALL NEW SEPARATOR PLATE TO TRANSMISSION BOLTS IF MISSING OR DAMAGED. (FIGURE 1)
Figure 1 - Article 08-2-10
PART NUMBER PART NAME
8R3Z-7007-A Separator Plate
W500231-S439 Bolt
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
080210A 2005-2008 Mustang Built Before 12/13/2007: Replace Separator Plate, Includes Time To Remove And Install Transmission (Do Not Use With 7003A, 5212B, 4602A) 2.8 Hrs.
DEALER CODING
BASIC PART NO. CONDITION CODE
6A373 07
Attached Thumbnails