BMW E32 valve train ticking and camshafts
Why does the E32 valve train tick or rattle?
In the M30 engine the cause is often lack of lubrication to the camshaft, where worn cams break the rocker arms. The valve train is never completely silent, and adjusting the valves or new parts may only change the sound. Keep the clearances at the manufacturer's values. If the clatter does not go away with adjustment, check the camshaft oil feed pipe, the timing chain and its guides.
Does the E32 M70 V12 engine have hydraulic valve lifters?
Yes, the M70 has hydraulic lifters. Loud ticking points to poor condition of the cams and lifters. You can try to ease the noise of dirty lifters with a flushing oil, but the ticking should not be tolerated for long, because the cams wear and replacing them is expensive.
What should you do when an M30 rocker arm breaks?
Fit a new camshaft and rocker arms, because a worn camshaft or tired valve springs are possible causes. The first rocker arm next to the chain requires removing the cylinder head, because the rocker shaft cannot be moved with the head bolts in place. The adjusting shims must be fitted the right way round, and the clearances are checked after tightening the eccentrics.