CONTENTS
SOUNDS
UNDERHOOD
RHYTHMIC

SHARP, METALLIC, RAPPING NOISE

CONDITION(S)

• SHARP, METALLIC, RAPPING NOISE WITH ENGINE SPEED HELD CONSTANT
• NOISE IS LOUDEST AFTER ENGINE IS WARMED UP AND QUIETEST ON COLD ENGINE
• NOISE DIMINISHES WHEN COASTING OR OUT OF GEAR

POTENTIAL CAUSE(S)

CHECK THESE FIRST:

1. LOW OIL LEVEL
Add oil if necessary.

2. THIN OR DILUTED (CONTAMINATED) OIL
Change oil and filter; use correct grade of oil.
Alter driving habits.

3. DEFECTIVE OIL PUMP
Have oil pump professionally replaced.

4. LOW OIL PRESSURE
Have cause of low oil pressure professionally corrected.

CHECK THESE NEXT:

5. WORN OR DIRTY CONNECTING ROD BEARINGS
Have connecting rod bearings professionally replaced.

6. OUT-OF-ROUND CONNECTING ROD BEARING JOURNALS ON CRANKSHAFT
Have crankshaft professionally replaced.

CHECK THESE LAST:

7. BENT OR INCORRECTLY ALIGNED CONNECTING RODS
Have connecting rods professionally serviced.

8. DEFECTIVE FUEL PUMP
Have fuel pump professionally replaced.

9. LOOSE OR CRACKED FLYWHEEL OR TORQUE CONVERTER
Have flywheel or torque converter professionally serviced.

CONTENTS
NOISY PISTON RINGS
ENGINE BACKFIRES