Questions and Answers

1987 BMW M3 Valve Adjustment Q. I own a 1987 BMW M3 (E30). My car idles smoothly from cold start, when it reaches at operating temperature, the idling gets rough. What could be the problem?

A. As discussed, here is the procedure for adjusting those valves. I'm sorry for the poor quality of the pictures, but it was the best I could do.

ADJUSTING VALVE CLEARANCE:

• Remove cylinder head cover.

• Crank engine with Special Tool 11 3 020.

• Measure valve clearance of cams facing up.

• Compare measured valve clearance with the specified valve clearance. Nominal values:

0.26 to 0.35 mm (0.010 to 0.014") - cold.
0.31 to 0.40 mm (0.012 to 0.016") - warm.

• If the valve clearance is not within specified tolerances, turn openings of tappets as shown.

• Guide in Special Tool 11 3 170 according to camshaft "A" (exhaust) or "E" (intake) and press tappets down.

• Blow out valve shim with compressed air.

• Measure thickness of removed valve shim.

• Install shim of required thickness with the lettering facing down.