VR6 cylinder head disassembly
♦ Remove all accessible parts of the Volkswagen Transporter T4 if not already done. Secure the block head in a vice to the bracket attached to the exhaust manifold studs. Now you can start disassembling the cylinder head.
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146 Fastening parts for camshafts and ignition distributor 1 - bearing cap, 2 - nut, 20 Nm, 3 - camshaft, 4 - drive sprockets, 5 - bolt, 100 Nm, 6 - distributor drive, 7 - ignition distributor, 8 - screw, 10 Nm, 9 - distributor sealing ring
♦ Then remove the camshafts.
♦ Rotate the crankshaft to TDC on the first cylinder.
It is necessary to turn out the spark plug of the first cylinder in order to accurately determine the TDC position. ♦ When disassembling the cylinder head.
Remove the ignition distributor. ♦ Remove the valve cover if you have not removed the engine from the vehicle.
♦ Remove the camshaft drive gear cover.
♦ After securing the camshaft against rotation with a 2 mm open-end wrench on the hexagon (see Fig. 147), unscrew the bolt securing the corresponding sprocket.
♦ Remove the chain tensioner (6, see fig. 143) from the side of the cylinder head. Remove the drive sprockets from the camshafts. If the drive chains have not yet been removed, then before dismantling it is necessary to mark the direction of movement of the double-row chain with paint, as shown in fig. 148 to return it to its original position during assembly. If the chain remains on the crankshaft sprocket, then it must be tied so that it cannot slip off. First, it is recommended to remove the camshaft of cylinders 1,3 and 5. To do this, loosen and then completely unscrew the nuts of the covers (see Fig. 149), remove the covers of the end supports 1 and 7. To gradually weaken the tension of the valve springs, alternately and crosswise, you should Loosen the nuts of the bearing caps 3 and 5 until the nuts can be unscrewed by hand. Remove the camshaft from the supports.
Rice. 147 Hexagons on the camshafts, with which you can fix the shafts from turning
Rice. 148 Paint the direction of the chain to facilitate disassembly of the block head
Rice. 149 Numbering of camshaft bearing caps. Each cover is marked with an arrow pointing towards the drive chain
Remove the camshaft of cylinders 2,4 and 6 in the same way.
♦ Remove the tappets. Mark them in place. It is best to mark the pushers with dashes, i.e., the first pusher - one dash, the second pusher - two, etc. (see Fig. 150). Number 1 is located on the drive chain side of the motor. Do not lay the pushers on their side, they must be installed with the working surface down. Pushrods are hydraulic non-return valves and must be handled with reasonable care. To compress the valve springs (to dry out the valves) at VW branded service stations, tool 2036 is used (see Fig. 151).
Rice. 150 Method of marking hydraulic pushers
Rice. Fig. 151 Removing the valves with the VW special tool
♦ The tool plunger must match the inside diameter of the upper valve spring seat.
Compress the spring until the valve cotters can be removed. ♦ To remove the valves, you can use a pipe of the appropriate diameter, which is installed on the upper spring plate.
On the other hand, a bar must be installed under the valve head. Tap the pipe with a hammer to pop out the valve cotters. These crackers remain inside the pipe. Keep the pipe pressed against the spring plate so as not to lose crackers. You can also put a rag under the pipe. ♦ When disassembling the cylinder head, remove the top plate and both springs. Remove the valve stem seals, these caps must be replaced at each disassembly. On fig. 152 shows the valve drive device.
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152 Block head valve actuator 1 - hydraulic tappet, 2 - valve cotters, 3 - upper plate of valve springs, 4 - springs, 5 - valve stem seal, 6 - guide, 7 - block head, 8 - valves
If the vehicle has a high mileage and a head repair is needed, it is very important to measure dimension "a" before assembling the cylinder block. We will dwell on this work in more detail.
Conveyor - oil pressure. Description of the VR6 engine .