I may have had a lean condition also at cold start idle. I had alot of symptoms at cold start idle of a air intake leak. When I removed the intake manifolds it appears to have been confirmed looks like it was sucking oil out of those center oil ports on the heads,and the gaskets were all wet.No water leaks heads are straight manifold also straight. Looks like it only did this cold. When the engine warmed up it was fine. (expansion)
Today I am going to see if the air flows thru both cyl heads for the air injection system.
Really not bad for 260k

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88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg