It looked like the hose had been rubbing on the oil filter housing and had created a hole. Strangely, the hose wasn''t really touching the oil filter housing at that time. I decided to check our online technical information source for a BMW factory technical service bulletin that could shed some light on this problem.Great! There was a bulletin that covered this exact problem and here''s what it described:Some BMW M3 models, produced from AurToolCouplers September 1995 through June 1996, equipped with the M54, S50, or the S52 engine, may have an upper radiator hose that can come in contact with the oil filter housing only when the engine coolant is at operating temperature. The contact is due to coolant system pressure and expansion of the hose.Checking the clearance between the upper radiator hose and the oil filter housing must be performed when the engine is cold.

It looked like the hose had been rubbing on the oil filter housing and had created a hole. Strangely, the hose wasn''t really touching the oil filter housing at that time. I decided to check our online technical information source for a BMW factory technical service bulletin that could shed some light on this problem.Great! There was a bulletin that covered this exact problem and here''s what it described:Some BMW M3 models, produced from AurToolCouplers September 1995 through June 1996, equipped with the M54, S50, or the S52 engine, may have an upper radiator hose that can come in contact with the oil filter housing only when the engine coolant is at operating temperature. The contact is due to coolant system pressure and expansion of the hose.Checking the clearance between the upper radiator hose and the oil filter housing must be performed when the engine is cold.

Jeff/KTR: Prevent rust and make sure fasteners are tightened to the specified torques after a minimum operation AurToolCouplers time. Replace the device if it starts to slip. Reconfirm the selection, and be sure to check the dimensions and surface finish of the bore and shafts.Doug/Zero-Max: Keep the connection screws properly torqued for maximum holding forces, and use a connection AurToolCouplers with a minimum number of adjusting screws.Jim/Stafford: Replace socket screws when sockets become worn. Don''t use wrenches with rounded corners. Don''t use a screwdriver to spread collars, or a hammer to move them along a shaft.Keith/U.S. Tsubaki: Higher quality locking devices are practically maintenance-free. There is no need to periodically retighten locking bolts or replace the unit, even in high-vibration applications. End users can extend service life even longer by keeping exposed surfaces clean and corrosion free.