Important: Before diagnosing the symptom, check service bulletins for updates.

DEFINITION: Fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.

1

Were the Preliminary Checks performed?

Go to Step 2

Go to Symptoms - Engine Controls

1. Inspect for crossed or crossfiring ignition wires.
2. Measure the ignition system output voltage for all cylinders using a spark tester.
3. Inspect the spark plugs for excessive wear, burned electrodes, improper gap, or heavy deposits.

Is a repair necessary?

Go to Step 3

Go to Step 4

Repair or replace any ignition system components as needed.

Did you complete the repair?

System OK

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1. Inspect the fuel system operation.
2. Inspect the fuel injectors by performing an injector diagnosis.

Is a repair necessary?

Go to Step 5

Go to Step 6

Repair or replace any fuel system components as needed.

Did you complete the repair?

System OK

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1. Inspect the exhaust gas recirculation (EGR) gasket for a leak or a loose fit.
2. Inspect the EGR valve for proper operation.
3. Inspect the intake manifold and the exhaust manifold for a casting flash.

Is a repair necessary?

Go to Step 7

Go to Step 8

Repair or replace any components as needed.

Did you complete the repair?

System OK

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1. Inspect the timing belt for proper installation and tension.
2. Inspect the engine compression.
3. Inspect the intake manifold gasket and the exhaust manifold gasket for leaks.
4. Inspect for sticking or leaking valves.
5. Repair or replace any components as needed.

Did you find and correct the condition?

System OK

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