Is your 2005 Mercedes-Benz SLK350 with the M272 engine showing signs of potential balance shaft wear? With 48,000 miles on the clock, concerns about the balance shaft issue are understandable for SLK350 owners. One owner recently checked their cam timing marks, noting that the marks align at 301 degrees engine indexing but are slightly off at 305 degrees. This raises the question: does this cam timing observation indicate a balance shaft problem in their 2005 SLK350?
To understand this better, let’s delve into the balance shaft issue prevalent in some Mercedes-Benz M272 engines, particularly those around the 2005 model year. The balance shaft, crucial for engine smoothness, could experience premature gear wear. This wear can lead to timing chain stretch and misalignment of camshaft timing.
Checking the cam timing marks is a good initial step. Ideally, when the engine is indexed at the correct position, the timing marks on both camshafts should be perfectly aligned. Slight deviations, especially when indexing changes by a few degrees (like from 301 to 305 degrees), might suggest timing chain elongation or balance shaft gear wear. If the balance shaft gear is significantly worn, it would be less likely to achieve proper cam timing alignment at any engine indexing point.
However, it’s important to note that minor discrepancies in cam timing can sometimes occur due to normal engine tolerances or slight chain stretch over time, even without significant balance shaft wear. Mercedes-Benz service might downplay the issue if the symptoms are not severe, as early stages of wear might not trigger immediate engine performance problems.
For a 2005 Mercedes-Benz SLK350 owner observing these timing mark variations, further investigation is advisable. A diagnostic scan using Mercedes-Benz diagnostic tools like XENTRY can provide fault codes related to camshaft timing or crankshaft-camshaft correlation. Additionally, physically inspecting the timing chain tensioner extension can offer insights into chain stretch. In more severe cases, valve cover removal allows for a direct inspection of the balance shaft gear teeth for wear.
While perfectly centered cam timing marks are reassuring, any deviation, especially in conjunction with engine noises or performance concerns, warrants a thorough check. Don’t solely rely on the initial cam timing mark observation. Combine it with diagnostic scans and potentially a physical inspection to accurately assess the condition of the balance shaft in your 2005 Mercedes-Benz SLK350. This comprehensive approach will provide a clearer picture beyond just the timing marks and address your concerns effectively.
