Mazda 6 Service Manual: No.7 slow return to idle

No.6 cranks normally but will not start

No.8 engine runs rough/rolling idle

Other materials:

Mazda 6 Service Manual: Engine coolant
ENGINE COOLANT LEVEL INSPECTION Verify that the coolant level in the coolant reservoir is between the F and L marks. If the engine coolant level is below L, remove the radiator cap and add coolant. (See COOLING SYSTEM SERVICE WARNINGS.) ENGINE COOLANT REPLACEMENT Warning Drain the ...

Mazda 6 Service Manual: Engine Exhaust (Carbon monoxide)
WARNING Do not drive your vehicle if you smell exhaust gas inside the vehicle: Engine exhaust gas is dangerous. This gas contains carbon monoxide (CO), which is colorless, odorless, and poisonous. When inhaled, it can cause loss of consciousness and death. If you smell exhaust gas inside the ...