P1247 Code: Complete DIY Repair Guide

The P1247 trouble code indicates a problem with the turbocharger boost pressure being lower than expected. This diagnostic code is typically set when the engine control module (ECM) detects that the actual boost pressure is significantly below the commanded boost pressure for a specified period of time.

Boost Pressure Leak

Symptoms:

• Reduced engine power
• Poor acceleration
• Whistling or hissing noise from the engine bay
• Intermittent P1247 code activation

A boost pressure leak is one of the most common causes of the P1247 code. Leaks can occur in various components of the turbocharger system, reducing the amount of pressurized air reaching the engine.

Diagnosis:

1. Visually inspect all boost hoses and connections for signs of damage or looseness.
2. Check the intercooler for cracks or damage.
3. Use a smoke machine to pressurize the system and locate any leaks.
4. Listen for any unusual whistling sounds while the engine is running.

Solution:

• Replace damaged hoses or clamps
• Repair or replace the intercooler if damaged
• Tighten any loose connections

Cost estimate: $50-$500, depending on the extent of the leak and parts needed.

Warning: Always allow the engine to cool before working on turbocharger components, as they can become extremely hot during operation.

Wastegate Failure

Symptoms:

• Inconsistent boost pressure
• Overboost or underboost conditions
• Engine power fluctuations
• Rattling noise from the turbocharger area

The wastegate regulates boost pressure by controlling exhaust gas flow to the turbine. A stuck or malfunctioning wastegate can cause boost pressure issues.

Diagnosis:

1. Inspect the wastegate actuator for proper movement.
2. Check the wastegate valve for carbon buildup or damage.
3. Verify the wastegate control solenoid functionality using a multimeter.
4. Test the wastegate spring tension.

Solution:

• Clean the wastegate valve if carbon buildup is present
• Replace the wastegate actuator if faulty
• Repair or replace the turbocharger if internal damage is found

Cost estimate: $200-$1500, depending on whether a repair or full turbocharger replacement is needed.

Boost Pressure Sensor Malfunction

Symptoms:

• Erratic boost readings
• Engine performance issues
• Check Engine Light illumination
• Intermittent P1247 code setting

The boost pressure sensor, also known as the MAP (Manifold Absolute Pressure) sensor, measures the pressure in the intake manifold. A faulty sensor can cause incorrect readings, leading to boost control issues.

Diagnosis:

1. Check the sensor’s wiring harness for damage or corrosion.
2. Test the sensor’s output voltage using a multimeter.
3. Compare the sensor readings with a known good sensor.
4. Inspect the vacuum line connected to the sensor for leaks or blockages.

Solution:

• Clean the sensor and its connections if dirty
• Replace the boost pressure sensor if faulty
• Repair any damaged wiring or vacuum lines

Cost estimate: $50-$200, primarily for the cost of a new sensor if needed.

Turbocharger Mechanical Problems

Symptoms:

• Blue or gray exhaust smoke
• Excessive oil consumption
• Whistling or whining noise from the turbocharger
• Significant loss of engine power

Internal turbocharger issues, such as worn bearings or damaged compressor/turbine wheels, can lead to reduced boost pressure and trigger the P1247 code.

Diagnosis:

1. Check for excessive play in the turbocharger shaft.
2. Inspect the compressor and turbine wheels for damage.
3. Look for oil leaks around the turbocharger.
4. Perform a boost leak test to rule out other issues.

Solution:

• Rebuild the turbocharger if internal components are worn
• Replace the entire turbocharger assembly if severely damaged
• Address any oil leaks or lubrication issues

Cost estimate: $500-$2500, depending on whether a rebuild or full replacement is necessary.

Note: Turbocharger replacement often requires specialized tools and expertise. Consider seeking professional help for this repair.

Intercooler Clogging or Restriction

Symptoms:

• Reduced engine performance
• Higher than normal exhaust gas temperatures
• Poor fuel economy
• Intermittent boost pressure issues

A clogged or restricted intercooler can reduce the efficiency of the turbocharging system, leading to lower boost pressure and potential P1247 code activation.

Diagnosis:

1. Visually inspect the intercooler for external damage or debris.
2. Check the intercooler fins for bent or damaged areas.
3. Perform a pressure drop test across the intercooler.
4. Inspect intercooler hoses for collapse or internal obstruction.

Solution:

• Clean the intercooler using appropriate cleaning methods
• Repair or straighten damaged intercooler fins
• Replace the intercooler if severely damaged or clogged
• Replace any collapsed or damaged intercooler hoses

Cost estimate: $100-$800, depending on whether cleaning or replacement is required.

Closing Thoughts

The P1247 code, indicating low turbocharger boost pressure, can stem from various issues within the turbocharging system. While some causes like boost leaks or sensor malfunctions can be addressed by DIY mechanics, others may require professional intervention. Always prioritize safety and consult a certified technician if you’re unsure about any aspect of the diagnosis or repair process.

Regular maintenance of your vehicle’s turbocharging system, including timely oil changes and air filter replacements, can help prevent many of the issues that lead to the P1247 code. By addressing this code promptly and thoroughly, you can ensure optimal performance and longevity of your turbocharged engine.

Frequently Asked Questions About P1247

• Can I drive my vehicle with the P1247 code active?
  While the vehicle may still run, it’s not recommended to drive for extended periods with this code active. Reduced boost pressure can lead to poor performance and potential engine damage if left unaddressed.
• How often should I service my turbocharger to prevent P1247 issues?
  Follow your vehicle manufacturer’s recommended maintenance schedule, typically every 30,000 to 50,000 miles. Regular oil changes and air filter replacements are crucial for turbocharger health.
• Will a P1247 code clear itself?
  The code may clear if the issue resolves temporarily, but it will likely return if the underlying problem isn’t fixed. It’s best to diagnose and repair the cause rather than relying on self-clearing.
• Can a clogged air filter cause a P1247 code?
  Yes, a severely clogged air filter can restrict airflow to the turbocharger, potentially causing low boost pressure and triggering the P1247 code. Regular air filter replacement is important for turbo health.
• Is it normal for boost pressure to fluctuate slightly?
  Some variation in boost pressure is normal, especially during different driving conditions. However, significant or sudden changes may indicate a problem that could lead to a P1247 code.
• Can using the wrong type of oil cause turbocharger issues and P1247 codes?
  Yes, using oil that doesn’t meet the manufacturer’s specifications can lead to inadequate lubrication and potential turbocharger damage. Always use the recommended oil type and viscosity for your turbocharged engine.
• How long does it typically take to diagnose and repair a P1247 code issue?
  Diagnosis can take 1-3 hours, while repair time varies greatly depending on the cause. Simple fixes like replacing a sensor might take an hour, while turbocharger replacement could require 4-8 hours of labor.
• Can aftermarket performance modifications trigger a P1247 code?
  Yes, modifications that alter boost pressure or air intake can potentially trigger a P1247 code if they’re not properly calibrated or if they cause the ECM to detect unexpected boost levels. Ensure all modifications are compatible with your vehicle’s systems.