Removal and installation the camshaft — model 525tds (BMW 5 Series E39)

Note: This describes the removal and installation of the camshaft for the M51S engine (model 525tds). Instructions for the M47 engine (model 520d) are given at the end of the chapter.

Since special BMW tools are required to perform the work, it is recommended that this work be performed at a BMW service station. The camshaft can be removed either with the cylinder head removed or installed. Below is a description of how to remove the camshafts with the cylinder head removed. This also applies to the installed cylinder head, but in this case, preliminary work must be performed before loosening the bolts securing it, in accordance with the instructions in the chapter "Removing and installing the cylinder head".

If necessary, measure the clearances before removing the camshaft. The prescribed value of the axial clearance: 0.15-0.33 mm; radial clearance: 0.04-0.081 mm.

Removal

Remove the cylinder head, see page 16.



To remove the camshaft, you will need the BMW 11 3 330 tool. The tool is designed to hold all the camshaft bearings in the mounting position when the cover fasteners are released. Install the tool and screw it on with the cylinder head cover fastening bolts, see the figure.



Press the bearing caps by turning the eccentric shaft of the device.

Loosen all bearing caps.

Loosen the device and remove it.

Remove the bearing caps and camshaft. The bearing caps on the outlet side are marked 1 through 7.



If required (for example, when it is necessary to remove valves), then remove the valve tappets. At the BMW service station, suction cups are used to remove the tappets, which are placed on top of the tappets. The tappets, if they were removed from the block, must be installed in their original places.

Caution: Removed valve tappets must not be kept upside down for more than 10 minutes, as this will cause the engine oil to slowly leak out of them and the automatic compensation of the valve drive clearance will stop.

Installation

Caution: If the camshaft has been removed, the following must be observed. The hydraulic tappets expand without load from the camshaft and require some time to contract again after installation. Therefore, the valves may open for a longer time than determined by the valve timing adjustment and collide with the piston. Therefore, it is necessary to ensure that a certain time is maintained between installation of the camshaft and installation of the cylinder head: at +20°C (room temperature) — 4 minutes, at +10°C — 11 minutes. After installing the cylinder head, wait another 30 minutes before turning the engine crankshaft.

If the camshaft was removed from the cylinder head installed on the engine, turn the engine crankshaft approximately 30° past TDC in the direction of its rotation (to the right, behind the hexagon on the belt pulley). This will ensure that no piston is at TDC and the valves cannot touch the pistons. Install the camshaft and wait the time specified above. Only then return the crankshaft to the TDC position and install the camshaft drive chain, see the chapter "Removing and installing the cylinder head".

Check the valve tappets for wear and scratches, replace if necessary. Install each tappet in the same place it was before removal.

Lubricate the camshaft bearings with engine oil and insert the camshaft so that the tops of the cams for the intake and exhaust valves of the first cylinder are facing upward equally.

Install the bearing caps in accordance with the existing markings. The caps must be installed in the same places they were before removal.

Install the fixture and tighten the bearing caps.

Using ½ turn steps, tighten the camshaft bearing caps evenly in a crosswise manner in the sequence "from the outside to the inside" to a torque of 15 Nm.

Loosen the device and remove it.

Install the cylinder head.