I dont have a ms6... but Im going to guess vvt pin problem
... still in warranty?
MULTI-MODEL - VARIABLE VALVE TIMING NOISE WHEN STARTING ENGINE
2007 Mazdaspeed3 vehicles
with VINs lower than JM1BK******742222 (produced before April 1, 2007)
2006-2007 Mazdaspeed6 vehicles with VINs lower than JM1 GG******109660 (produced before April 1, 2007)
2007 Mazda CX-7
vehicles with VINs lower than JM3ER******166945 (produced before April 1, 2007)
When the engine is started, some vehicles may exhibit a loud ticking noise from the variable valve timing actuator at first start for a couple of seconds. This is caused by the lock pin of the variable valve timing actuator not fully engaging. Heat treatment has now been added around the hole of the variable valve timing rotor lock pin to prevent this from happening.
Customers having this concern should have their vehicle
repaired using the following repair procedure.
1. Verify customer concern.
2. Replace the variable valve timing actuator after the engine cools down. Refer to Workshop Manual section 01-10.
3. Do an engine flush and replace the oil filter with a new one to remove dust and metal particles from the engine.
4. Verify repair.
Part Number: L3K9-12-4X0B
Description: Variable Valve Timing Actuator
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.
Warranty Type: A
Symptom Code: 82
Damage Code: 9C
Part Number Main Cause: L3K9-12-4X0B
Operation Number / Labor Hours::XXC0YXRX / 3.2 Hrs. (CX-7), 3.3 Hrs. (Mazdaspeed3), 3.6 Hrs. (Mazdaspeed6)
Copyright © Mazda North American Operations
If you're under any type of warranty, take her in asap, with TSB literature in hand.
If you're not under warranty, I have seen dealer quotes ranging from $700-$1200 to repair this issue.