Autodata Technical Issue 54 – Engine oil leak from front of engine in 2011 BMW Z4
Each month the Autodata team answers a common technical question and provides a printable document with technical diagrams to download and keep, exclusively for IGA members.
Q.We have a 2011 BMW Z4 2,0 petrol in the workshop with an engine oil leak from the front part of the cylinder head cover. We replaced the cylinder head cover gasket at the last service but there seems to be engine oil in a similar area as before. Are you aware of anything that could be causing this engine oil leak?
A. We are aware of an engine oil leak in the area you describe which affects several models in the BMW range with N20 engine code built 01/03/11-01/10/11. The oil leak is due to an unsatisfactory design of the timing chain tensioner sealing washer. You may also experience excessive timing chain noise. Check the valve timing and adjust if necessary. Remove the timing chain tensioner and inspect sealing washer (fig. 1).
Fit modified timing chain tensioner sealing washer. Refit the timing chain tensioner and tighten to the correct torque setting. Thoroughly clean the affected area. Carry out road test to confirm the fault has been rectified.
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