Audi A8 3.0TDI after 30K and 6 years, noisy engine ?We carried out inspection for warranty company

Summary

In this video, the mechanic investigates a 2017 Audi A8 with a 3.0 TDI engine exhibiting a mysterious tapping noise. After performing a diagnostic check, the mechanic identifies potential issues with the timing chain, sprockets, and carbon buildup. Despite the car's low mileage of 30,000 miles, the engine shows signs of wear, particularly in the camshaft and sprockets. A detailed inspection is conducted, leading to the conclusion that major components like the camshafts, sprockets, and timing chain may need replacement. The mechanic also prepares a report for the warranty company, with a comprehensive repair quotation following the findings.

Takeaways

• 😀 The video focuses on diagnosing and repairing an Audi A8 3.0 TDI with a mysterious tapping mechanical noise despite having only 30,000 miles.
• 😀 The mechanic discusses the car's clean engine, with no visible oil or coolant leaks, and highlights the presence of high-frequency tapping noise from cylinder bank one (cylinders 1-3).
• 😀 The mechanic uses a diagnostic tool to check injector values and confirms the noise is not coming from the injectors, indicating it's a mechanical issue.
• 😀 Visual inspection reveals damage on the sprockets, including metal flaking, and a possible misalignment of the timing chain sprockets.
• 😀 The mechanic suspects the noise may be related to an issue with the timing chain tensioner, possibly causing engine knock when combined with the sprocket damage.
• 😀 Despite the low mileage of the vehicle, carbon buildup is evident, although not as severe as expected for the mileage.
• 😀 The mechanic suspects the issue could be related to a failing camshaft, timing chain, or tensioner and recommends further inspection of the engine components.
• 😀 A technical report and quotation are prepared for the warranty company, detailing labor hours, parts, and the repair cost, with the most expensive items being the camshaft and timing chain replacement.
• 😀 The mechanic acknowledges that timing chain issues are common in Audi's TDI engines, especially in models manufactured after 2014, and expresses concern over the cost of repairs for such a relatively new vehicle.
• 😀 The video ends with the mechanic discussing the warranty claim process, including challenges with part availability and the time needed for repair, and invites viewers to follow along for updates.

Q & A

What is the issue with the Audi A8 engine in the video?

The Audi A8 engine is producing a mysterious high-frequency tapping noise coming from bank one, cylinders one to three, despite having low mileage (30,000 miles). The noise seems mechanical, and the cause needs further inspection.

Why is the bonnet release handle positioned on the wrong side of the Audi A8?

The bonnet release handle is located on the wrong side because the manufacturer, Audi, opted to place it there, despite the high cost of the vehicle. This decision was criticized as being inconvenient.

What diagnostic steps were taken to identify the cause of the noise?

The diagnostic steps included connecting the car to the diagnostic tool, checking the injectors, and running the engine while disconnecting the injectors to eliminate them as the source of the noise. The noise persisted, suggesting a mechanical issue.

What was the condition of the engine's carbon buildup?

The engine had minimal carbon buildup after 30,000 miles, which was less severe than expected. The video suggests that a chemical carbon cleaning might have helped prevent further buildup.

What mechanical issues were observed in the timing chain and sprockets?

There were issues with metal flaking on the sprockets and misalignment in the timing chain. The timing chain showed play between the two cylinder heads, suggesting that the tensioner was failing, potentially causing the noise and a knock from the cylinder head.

What were the potential causes of the mechanical noise in the engine?

The mechanical noise is likely caused by issues with the timing chain tensioner, sprockets, and possibly the camshaft. The tensioner is suspected of failing, which could lead to a misalignment of the sprockets and a knock sound from the engine.

What steps were suggested to address the engine issues?

The suggested steps included stripping down the engine to inspect the camshaft and timing chain system, replacing the timing chain, tensioners, and possibly the camshaft if damaged. A technical report and quotation were also prepared for the warranty company.

What is the proposed solution for the engine's timing chain and sprocket issues?

The proposed solution involves replacing the camshafts, sprockets, and potentially the timing chain kit. However, the focus would be on replacing the tensioners rather than the entire chain, to reduce costs.

How much did the repair quotation amount to?

The repair quotation was £8,700, which included £6,200 for the timing chain kit, sprockets, camshafts, and 24 hours of labor. An additional three hours of labor and extra parts were charged for cleaning the intake manifold due to carbon buildup.

What challenges did the mechanic face in acquiring the necessary parts for repair?

The mechanic faced delays in obtaining the camshafts, as they were on backorder. The parts could take anywhere from 10 days to 4 weeks to arrive, depending on availability.