M30 valve adjustment & banjo bolts
I have adjusted the valves on my 535iA. I set them to .0012" (12 thou) cold.
This equates to .0014" hot. The original clearances were pretty close. None were tight or loose by more than a thou or so so. While I was at it I checked the camshaft oil feeder pipe banjo bolts. The rear was slightly loose (spanner loose not finger loose if you get my point) All the cam lobes looked in good condition with no signs of unusual or excessive wear. However I have decided to remove the bolts and replace both along with the aluminium crush washers. I will loctite and wire the new ones in! As you can see from the picture this design fault was an engineering hiccup to say the least. If the bolt is overtightened it will crush the oil pipe and prevent any oil from reaching the cam & rockers. If too loose the oil leaks off around the banjo bolts and... ditto!!
Pretty clean here... a sign of regular oil changes!
Close up of banjo bolt (center)... I wonder if they sacked the guy who designed this bit! The oil pipe flattens where it is held by the bolt. Torque is specified at no more than 8-10 ft/lbs. Any more and you risk pinching off the pipe and restricting the oil flow. Loctite and lockwire seems the only way to solve this problem. Crush washers cannot be reused as they are designed to deform when the bolt is torqued and seal against oil leakage - provided the bolt doesn't come loose of course.
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