Removing and installing valves

All engines Removal

Caution: if valve train parts are reused, they must be reinstalled in exactly the same position.

To avoid mix-ups, it is recommended to make a suitable parts tray. Always replace the valve stem seals.

• Remove the cylinder head and place it on two wooden blocks.

• 1.4 L / 1.8 L / 1.9 L engine: remove the camshaft, see page 50.

• 1.6 L engine: unbolt the camshaft housing from the cylinder head, see page 37.

• All except 1.4 L engine: mark the tappets and remove them.

  If necessary, use a rubber suction cup to pull them out. The illustration shows the diesel engine, whose tappets have adjusting shims.

• Remove the valve springs. Workshops use a special tool for this. The valve cone halves - and thus the valves including the valve springs - can also be removed using a commercially available valve spring compressor.

1. 1

   Lower valve spring seat

2. 2

   Valve stem seal

3. 3

   Valve spring

4. 4

   Upper valve spring retainer

5. 5

   Valve cotters.

• Compress the valve springs and remove the valve cotters. Remove the upper valve spring retainer and valve springs. Pull out the valve. Depending on the engine, there may be 2 valve springs per valve.

• Pull off the valve stem seal - 2 - with special pliers - 1 -.

  The Hazet valve stem seal pliers 791-5, for example, are suitable for this.

• Pull the valve out of the cylinder head toward the combustion chamber side.

• Remove the next valve.

Installation

• Lightly oil the valve stem and install each valve in the same position as before removal. Lightly lap new valves into their seats with lapping compound, see page 54.

• Clean all parts thoroughly and lubricate moving parts with engine oil.

• To avoid damaging the valve stem seals - 1 -, cover the valve stem - 2 - at the contact surfaces of the valve cotters with smooth adhesive tape before installation. Remove the adhesive tape after installation.

• Lightly oil the valve stem seal and press it on with a suitable drift until it bottoms out.

• Lightly oil the valve stem and valve guide with engine oil, and insert the valve from below.

• Install the valve springs and upper valve spring retainers.

Caution: on engines with high mileage (over 100,000 km), it is recommended to replace the valve springs, as they weaken over time.

• Compress the valve spring with a spring compressor and install the valve cotters. Slowly release the valve spring while checking that the cotters are seated correctly.

• Then install the next valve. Do not mix up the intake and exhaust valves.

• After installing the valves, insert all bucket tappets into the cylinder head according to their markings. On diesel engines, place the associated shims in position, see upper arrow in figure R-10243. Coat the tappet bore in the cylinder head, the inside and outside of the tappets, and the shims on both sides with clean engine oil.

• 1.4/1.8/1.9 L engine: install the camshaft(s), see page 50.

• 1.6 L engine: screw the camshaft housing onto the cylinder head with a new gasket, see page 37.

• Install the cylinder head, see page 37.

• Diesel engine: adjust valve clearance, see page 55.