Experiencing car trouble can be frustrating, especially when it involves intermittent issues and multiple repairs. For owners of a 2006 VW Passat 3.6, encountering OBD2 codes alongside problems like high idle can be particularly perplexing. This article delves into a real-world scenario involving a 2006 VW Passat 3.6, the OBD2 codes it presented, and the steps taken to diagnose and address a persistent high idle problem.
The journey began with a dead battery, a common enough issue. However, upon jump-starting the vehicle, a new problem arose: the car wouldn’t start. Seeking professional help, an independent shop diagnosed a faulty fuel pressure regulator as the culprit, preventing the car from starting and running. The repair involved replacing the high-pressure fuel pump (HPFP) and, potentially, the cam follower. While the car was operational again, an intermittent high idle issue surfaced, ranging between 900-1250 RPM.
Despite the initial repair, the high idle persisted. A visit to a VW dealer became necessary due to the ongoing issue and the presence of a Malfunction Indicator Lamp (MIL). The OBD2 codes read at this point were crucial for further diagnosis. While the exact codes aren’t recalled with complete certainty, the user believes they included P2293, P0087, and indications of intermittent misfires. The VW dealer’s diagnosis pointed towards a faulty timing chain. This led to a significant repair involving the replacement of tensioners, chains, and potentially the camshaft, although the work order details are not entirely clear on the camshaft replacement.
Following the timing chain and related component replacement, the MIL was resolved, and initially, the high idle seemed to disappear. Unfortunately, the high idle issue returned. The owner, using an OBD2 Bluetooth adapter and the Torque app, observed a correlation between the high idle and an increase in fuel rail pressure. Fuel pressure readings appeared to jump from around 1000 at a normal idle of 650-700 RPM to 3000-4000 at the high idle range of 900-1300 RPM.
Interestingly, a temporary workaround was discovered. When the idle was slightly elevated around 900 RPM, tapping the accelerator pedal would cause the RPM to drop back down to a normal level of approximately 650 RPM. However, this “accelerator fix” was not a permanent solution and proved ineffective when the idle exceeded 1000 RPM.
The owner suspects that the persistent high idle issue might be linked to the cam follower, which was initially replaced along with the HPFP. The theory is that if the cam follower was installed onto a damaged camshaft during the first repair, it could have become damaged itself and is now contributing to the high idle and fuel pressure fluctuations. The vehicle is planned to be taken back for warranty service, as the initial high idle issue was never fully resolved, and the subsequent work was performed under a third-party extended warranty.
This case highlights the complexities of diagnosing car problems, particularly intermittent issues and potential cascading effects from initial component failures. For 2006 VW Passat 3.6 owners experiencing high idle and potentially related OBD2 codes like P2293 or P0087, this real-world example underscores the importance of thorough diagnostics and addressing the root cause of the problem to avoid repeated repairs and persistent issues. Further investigation, particularly focusing on the condition of the cam follower and its interaction with the camshaft, may be crucial in finally resolving the high idle problem in this 2006 VW Passat 3.6.
