Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

Other materials:

Mazda 6 Service Manual: Thermostat
THERMOSTAT REMOVAL/INSTALLATION 1. Remove the plug hole plate. 2. Disconnect the negative battery cable. 3. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS.) 4. Remove the drive belt. (See DRIVE BELT REPLACEMENT.) 5. Remove the washer tank. 6. Remove the P/S oil pump. Note ...

Mazda 6 Service Manual: Automatic transaxle fluid (atf) inspection
Automatic Transaxle Fluid (ATF) Condition Inspection One way of determining whether the transaxle should be disassembled is by noting: If the ATF is muddy or varnished. If the ATF smells strange or unusual. ATF Condition Automatic Transaxle Fluid (ATF) Level Inspection Caution Th ...