Experiencing a P0016 code on your 2016 Mercedes can be frustrating, especially when accompanied by prolonged cranking. This article details a step-by-step troubleshooting journey, offering insights for fellow DIY mechanics facing similar issues. We’ll explore the diagnostic process, parts replacements, and dealer interactions, all in pursuit of resolving this persistent engine code.
Initial Diagnostic Steps for a 2016 Mercedes P0016 Error
The journey began with a P0016 code and the symptom of extended cranking times specifically when the check engine light was illuminated. Clearing the code temporarily resolved the long crank issue, allowing for immediate starts, but the code would reappear after a brief period of engine operation.
To start, the camshaft sensors were tested thoroughly and found to be within specification. Despite these positive tests, a proactive approach was taken by replacing one camshaft sensor with a new OEM part. Sensor banks were swapped during this process, and the P0016 code was cleared each time to monitor if the issue shifted, but unfortunately, the problem persisted.
Next, attention was turned to the magnets. These components were also meticulously tested and confirmed to be functioning within their specified parameters. Power input to both the magnets and camshaft sensors was verified and passed inspection, ruling out electrical supply issues to these components.
Timing Chain Component Replacement and Continued P0016 Code
To address potential timing-related concerns, brand new camshaft sprocket adjusters, a timing chain, chain guides, and a tensioner were ordered. Due to time constraints, a local mechanic was entrusted with the task of replacing these components. Using the appropriate tools, the mechanic replaced all the parts. However, even after this extensive replacement, the engine continued to throw the same P0016 code.
Suspecting a sensor issue elsewhere, a brand new crankshaft sensor was purchased and installed. Initially, this seemed promising as the issue appeared to be resolved for about half an hour of intermittent engine running. Regrettably, the P0016 code returned.
The mechanic then re-examined the engine timing by disassembling it again. All timing marks were confirmed to be correctly aligned, eliminating the possibility of a jumped timing chain or misaligned timing. It’s important to reiterate that the engine ran exceptionally well once started, with the only issues being the check engine light and the prolonged cranking specifically when the light was on. Clearing the code resulted in immediate starts, but the extended cranking and code reappearance always returned.
Dealer Involvement and Questionable Diagnosis
Facing a dead end, the 2016 Mercedes was taken to a dealership for in-depth troubleshooting. The dealer’s diagnosis pointed towards an incorrectly installed tensioner. This diagnosis was met with skepticism, considering the mechanic’s experience and the perceived simplicity of tensioner installation. When questioned, the dealer admitted to primarily using computer diagnostics and not physically inspecting the chain case, raising further doubts about the accuracy and thoroughness of their assessment, especially given the cost incurred.
Shifting Focus to the Crankshaft and Seeking Further Advice
Having exhausted common solutions and questioned the dealer’s findings, the focus shifted towards a less conventional possibility: a crankshaft issue. The hypothesis is that the crankshaft itself might be bent or have a weld failure causing slight movement in the timing marks, as seen in some online videos related to similar issues in other car brands. The mechanic confirmed having encountered such crankshaft problems in Chevy and Subaru vehicles, lending some credence to this theory for Mercedes as well.
As the next step, the plan is to remove and inspect the crankshaft for these potential issues. Before proceeding with this, the decision was made to revert the engine assembly back to the original clamp tool method, as an earlier attempt to adjust timing by skipping a tooth resulted in rough engine running alongside the P0016 code.
Currently seeking further advice, the possibility of replacing the camshaft control valves is being considered, despite the significant cost. Any insights or recommendations from fellow Mercedes mechanics or enthusiasts regarding this 2016 Mercedes P0016 troubleshooting journey would be greatly appreciated.
