Valve guide bushings (BMW X5 E53)

The valve guides are made of a special brass alloy based on bronze and are pressed into the cylinder head. The parameters of the inlet and outlet valve guides are the same. The valve guides are cooled with liquid nitrogen to a temperature of minus 150°C and are pressed into the cylinder head, which has a temperature of 30-50°C.

The clearance check should be carried out using a device (Fig. 3.7). The maximum permissible clearance during operation between the valve stem and the guide bushing is measured by the maximum displacement of the valve head, when the valve stem is flush with the upper edge of the guide, and should be no more than 0.5 mm.



Checking the wear of valve guide bushings is especially important for engines with a long service life (mileage).

• Total sleeve length 43.5 mm;
• Inner diameter of the bushing, mm:
• nominal 6.0;
• 1st rem. size 6.1;
• 2nd belt size 6.2;
• Tolerance from 0.0 to + 0.015.