Note: A new or reconditioned head can be purchased from service stations and specialists. Since special tools and equipment are required to disassemble and inspect the head and its components, and since repairs may also require individual new parts that may not always be available, it may be more practical and cost-effective for the home mechanic to purchase a reconditioned head than to disassemble, inspect, and repair the old one. A spring compressor is required to perform the operation.
Four cylinder petrol engines
1. Remove the cylinder head as described in part A of this Chapter.
2. Remove the intake and exhaust manifolds as described in Chapter 4.
3. Remove the camshaft gear, valve lifters and camshaft as described in part A of this Chapter.
4. If desired, remove the spark plugs from the cylinder head.
5. Where required, unscrew the thermostat housing from the cylinder head.
6. Using a valve spring compressor, compress the valve spring and release the crackers. Release the spring and remove the spring retainer and spring (see Fig. 8.6, a-g).
Fig. 8.6, a. Compress the valve spring...
Fig. 8.6, b. And remove the crackers
Fig. 8.6, c....then the spring plate...
Fig. 8.6, g...and spring
7. Carefully remove the oil deflector caps from the guide bushings with pliers, then the spring plates (see Fig. 8.7, a, b).
Fig. 8.7, a. Remove the oil deflector cap
Fig. 8.7, b....and the spring plate
8. Remove the valve through the combustion chamber (see fig. 8.8).
Fig. 8.8. Remove the valve through the combustion chamber
9. The valve, spring and seats are a set and must not be separated during assembly. In addition, the valves must be stored in the sequence in which they were installed, unless the valve is replaced with a new one. If the valves are to be used further, it is recommended that each valve and its associated parts be stored in a separate polyethylene bag or similar container with a label (see fig. 8.9).
Fig. 8.9 Store each valve and related parts in a labeled plastic bag
Six-cylinder petrol engines
10. Remove the cylinder head as described in Part B of this Chapter.
Information copied from the website [mercedesman.ru]
11. Remove the intake and exhaust manifolds as described in Chapter 4.
12. Remove the camshaft gear, valve lifters and camshaft as described in part B of this Chapter.
13. Perform the actions described in paragraphs 5-9.
Diesel engines
14. Remove the cylinder head as described in parts of this Chapter.
15. Remove the intake and exhaust manifolds as described in Chapter 4.
16. If desired, remove the spark plugs as described in Chapter 5.
17. Perform the actions described in paragraphs 5-9.