Vehicle: 2005–2006 Jeep Liberty CRD (2.8L diesel)
Transmission: 545RFE automatic
I’m troubleshooting a persistent torque limitation under load and would appreciate input from anyone experienced with the CRD platform.
---
## Core Symptoms
- Engine starts easily and runs smoothly
- Revs cleanly in Park/Neutral up to ~2500 RPM with normal throttle response
- When shifted into Drive or Reverse, RPM rises only to about ~900 RPM and stops
- The vehicle tries to creep forward strongly, and RPM drops slightly when the transmission engages
- Heavy white/black smoke appears when the ~900 RPM limit is reached
- Returning to Park/Neutral immediately restores normal revving
---
## Fuel System Work / Tests
- Replaced the entire fuel filter head assembly (housing, heater, water sensor, filter)
- Installed clear line between filter head and CP3
- Observed large pulsing bubbles in this line while running
- To isolate the tank system, I ran the engine from an external fuel container
- Supply line from container → filter head
- Return line back into the same container
Results from the external tank test:
- No bubbles in the supply line from the container
- Still saw pulsing bubbles between the filter head and the CP3
- Engine ran ~1 hour at 1500–2000 RPM smoothly
- RPM remained stable
- Return flow to the container was steady
The high-pressure pump is the Bosch CP3.
---
## Sensor / Electrical Tests
- Code previously present: P0107
- MAP sensor replaced and wiring tested
- Unplugging the MAP sensor made no difference
- Unplugging the MAF sensor made no difference
---
## Additional Observations
- Engine holds steady RPM smoothly
- Immediate clean shutdown when the key is turned off
- Engine snaps up to RPM normally in Park
- Intake hose near the manifold shows little pressure change during light rev
- When the ~900 RPM wall occurs in gear, smoke increases significantly
- Vehicle creeps strongly at idle when in gear
The turbocharger is the Garrett GT2056V.
---
## Questions
1. Could a failed vacuum supply to the turbo actuator or stuck vanes on the GT2056V produce a situation where the engine revs normally in neutral but hits a ~900 RPM wall under load with heavy smoke?
2. Has anyone seen pulsing bubbles between the filter head and the CP3 even when the system is supplied from an external fuel container, and if so what was the root cause?
3. Is there any known failure mode on the Liberty CRD where the ECU limits torque in gear but allows normal revving in Park without setting additional fault codes?
4. Are there other common CRD faults that would allow normal neutral revving but severe torque loss in gear?
Any suggestions on where to focus the next diagnostic step would be greatly appreciated before I start replacing more components.
Transmission: 545RFE automatic
I’m troubleshooting a persistent torque limitation under load and would appreciate input from anyone experienced with the CRD platform.
---
## Core Symptoms
- Engine starts easily and runs smoothly
- Revs cleanly in Park/Neutral up to ~2500 RPM with normal throttle response
- When shifted into Drive or Reverse, RPM rises only to about ~900 RPM and stops
- The vehicle tries to creep forward strongly, and RPM drops slightly when the transmission engages
- Heavy white/black smoke appears when the ~900 RPM limit is reached
- Returning to Park/Neutral immediately restores normal revving
---
## Fuel System Work / Tests
- Replaced the entire fuel filter head assembly (housing, heater, water sensor, filter)
- Installed clear line between filter head and CP3
- Observed large pulsing bubbles in this line while running
- To isolate the tank system, I ran the engine from an external fuel container
- Supply line from container → filter head
- Return line back into the same container
Results from the external tank test:
- No bubbles in the supply line from the container
- Still saw pulsing bubbles between the filter head and the CP3
- Engine ran ~1 hour at 1500–2000 RPM smoothly
- RPM remained stable
- Return flow to the container was steady
The high-pressure pump is the Bosch CP3.
---
## Sensor / Electrical Tests
- Code previously present: P0107
- MAP sensor replaced and wiring tested
- Unplugging the MAP sensor made no difference
- Unplugging the MAF sensor made no difference
---
## Additional Observations
- Engine holds steady RPM smoothly
- Immediate clean shutdown when the key is turned off
- Engine snaps up to RPM normally in Park
- Intake hose near the manifold shows little pressure change during light rev
- When the ~900 RPM wall occurs in gear, smoke increases significantly
- Vehicle creeps strongly at idle when in gear
The turbocharger is the Garrett GT2056V.
---
## Questions
1. Could a failed vacuum supply to the turbo actuator or stuck vanes on the GT2056V produce a situation where the engine revs normally in neutral but hits a ~900 RPM wall under load with heavy smoke?
2. Has anyone seen pulsing bubbles between the filter head and the CP3 even when the system is supplied from an external fuel container, and if so what was the root cause?
3. Is there any known failure mode on the Liberty CRD where the ECU limits torque in gear but allows normal revving in Park without setting additional fault codes?
4. Are there other common CRD faults that would allow normal neutral revving but severe torque loss in gear?
Any suggestions on where to focus the next diagnostic step would be greatly appreciated before I start replacing more components.
