2
Remove and shake the PCV valve.
Does the PCV valve rattle?
Yes
Inspect for the following:
z
Damaged valve guide, stems or
valve seals
z
Blocked oil drain passage in
cylinder head
z
Piston ring is not seated, seized or
worn.
z
Damaged cylinder bore
If other driveability symptoms are
present, return to diagnostic index to
service any additional symptoms.
No
Replace the PCV valve.
3
Does the cooling system hold
pressure?
Yes
Inspect for the following:
z
Cylinder head gasket leakage
z
Intake manifold gasket leakage
z
Cracked or porous engine block
If other driveability symptoms are
present, return to diagnostic index to
service any additional symptoms.
No
Inspect for cause.
4
Inspect for the following:
z
Air cleaner restriction
z
Collapsed or restricted intake-
air system
z
Restricted fuel return line
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 4.
5
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON
position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
DTC is displayed:
Go to the appropriate DTC inspection.
(see
DTC TABLE [MZI-3.5]
.)
No
No DTC is displayed:
Go to the next step.
6
Install the fuel pressure gauge
between the fuel pipe and the fuel
distributor.
Start the engine and idle it.
Yes
Go to the next step.
No
Low:
Inspect the fuel line for clogging.
If there is no malfunction, replace the
2007 Mazda CX-9 Grand Touring
2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
Microsoft
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