Renault Espace DF311 & DF308 & DF569 DPF & Boost Faults

Renault Espace DF311 & DF308 & DF569: Fixing DPF and Boost Pressure Faults.

Starting the Vehicle Scan and Spotting Common Faults

* Number of regeneration failures exceeded
* Boost pressure circuit incoherence
* Particle filter blocked
* Engine deceleration too high

Some faults linked to injection multiplex signals were ignored since the battery was known to be weak, having been on charge recently.

What the Customer Told Us

The customer had driven 4 hours to get the vehicle checked. They’d recently had the DPF cleaned, but it clogged again quickly. The battery was known to be faulty but hadn’t been replaced yet. The main concern was the repeated DPF issues.

How Boost Pressure Affects DPF Regeneration

A blocked DPF often results from problems with boost pressure. If the engine doesn’t get the right amount of boost air, it can’t burn off the soot properly during regeneration. So, fixing boost faults is crucial before doing any DPF cleaning.

Checking the Boost Pressure Sensors

Using the diagnostic tool, we checked sensors for manifold pressure, boost pressure and atmospheric pressure. The readings were around 1,000 millibars, close to atmospheric pressure, showing the sensors themselves were working fine. This meant the problem wasn’t a faulty sensor.

Finding Boost Leaks with Smoke Testing

Next, we used the Launch UK Smoke 2 machine to spot any boost leaks. Smoke testing is very effective in these cases:

1. Connect the smoke machine to the boost pipe system.
2. Produce smoke and shine a torch along the pipes.
3. Wiggle the pipes to stress any weak spots.
4. Watch carefully for smoke escaping from cracks or holes.

In this Renault Espace, smoke came from a specific boost pipe. Moving the pipe made the leak bigger, showing a clear crack in the plastic pipe.

Temporary Fix for the Boost Pipe

The boost pipe is a Renault-specific part and not easy to get quickly. Since the customer was 4 hours away, a full replacement wasn’t possible on the spot. We glued the cracked section temporarily using a strong adhesive and activator. The customer ordered the new pipe from a Renault dealer and will replace it after the drive home.

It’s important to understand this fix is only temporary. Driving too far without a proper repair could cause the DPF to block again, wasting time and money.

Did Previous Repairs Cause the Problem?

The customer asked if their newly fitted EGR valve might have damaged the boost pipe. Since the pipe is old and brittle, handling it when working on the EGR can cause cracks. While it may have made things worse, the pipe simply needed replacing due to wear.

Confirming the Temporary Seal

After the glue dried, we repeated the smoke test. No smoke escaped this time, confirming that the pipe was sealed well enough to drive home safely.

Cleaning the DPF

The cleaning involved these steps:

1. Disconnect the DPF pressure sensor.
2. Attach a cleaning gun connected to an air compressor (8-9 bar).
3. Spray the cleaning fluid slowly into the DPF with the engine off to avoid fluid reaching the turbo.
4. Finish spraying with the engine running to aid fluid circulation.

Using a specialised cleaning fluid helped clear soot and debris inside the filter.

Checking Post-Cleaning Pressure and Fault Codes

Pressure readings after cleaning dropped to about 4-5 millibars.. However, the fault codes wouldn’t clear easily. This meant a DPF reset was necessary.

Struggling to Reset Fault Codes

Resetting the fault codes needed several scan tools: Launch, Autel, and Xtool. Some tools lacked the right menu or functions, and it took a few attempts with switching ignition on and off, plus a forced regeneration, before the Autel tool successfully cleared the codes.

This shows why it’s handy to have access to different diagnostic equipment for certain cars.

Final Checks and Road Test

With the fault codes cleared, soot levels reset to zero and differential pressure down to around 3 millibars, the Espace was ready for a road test. The glued boost pipe held up well. The customer was advised to get the genuine replacement pipe installed as soon as possible.

Quick Tips for DPF and Boost Faults on Renault Espace

* Always check for boost leaks before cleaning or replacing the DPF
* Smoke testing saves time by quickly showing leaks
* Be patient and try more than one diagnostic tool if you can’t clear fault codes
* Temporary fixes are just that — plan to replace parts properly.

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