how to diagnose the knocking noise in my Cadillac Escalade T1XX (2021-Present)

Symptoms

• Knocking noise that changes with engine RPM
• Noise present during acceleration and deceleration
• Possible loss of power or hesitation during acceleration
• Check engine light may or may not be illuminated
• Vibration felt through the steering wheel or floorboards

Diagnostic Steps

1. Scan for Error Codes: Use an OBD-II scanner to check for any diagnostic trouble codes (DTCs) that may indicate specific issues.
2. Inspect Engine Components: Visually inspect the engine for any loose components, damaged parts, or signs of oil leaks.
3. Check Engine Oil Level and Condition: Ensure the engine oil is at the correct level and assess its condition for contamination.
4. Perform a Sound Test: Use a mechanic’s stethoscope to localize the source of the knocking noise while the engine is running.
5. Inspect Exhaust System: Check for loose or damaged exhaust components that may create knocking sounds.
6. Evaluate Suspension Components: Inspect suspension parts such as bushings, struts, and control arms for wear or damage that could cause noise.

Solution

1. Preparation

• Tools Required: OBD-II scanner, mechanic’s stethoscope, basic hand tools (sockets, wrenches), flashlight, jack and jack stands.
• Park the vehicle on a flat surface and engage the parking brake.

2. Address Engine Component Issues

• Step 1: If any loose components are found, tighten bolts and fasteners to the manufacturer's specifications.
• Step 2: If damaged parts are identified, remove and replace them. For example, if a loose heat shield is the culprit, remove the shield and reattach it securely.
• Step 3: If the engine oil is contaminated, change the engine oil and replace the oil filter with the correct type specified in the owner’s manual.

3. Repair Suspension or Exhaust Components

• Step 1: If suspension components are worn, remove the affected parts and replace them with OEM or high-quality aftermarket parts.
• Step 2: For exhaust issues, replace any damaged gaskets, hangers, or pipes that show signs of wear or damage.