Adjusting valve clearances (VW Lt 28)

Valve clearances can be adjusted with the head removed. The condition for this is that the head is firmly supported on the table and there is sufficient distance between the table top and the bottom surface of the head, which allows some of the valves to be lifted.

Attention!

• The DV1G and DW1S engines have tappets with a hydraulic valve clearance reset device. These engines are identified by a sticker on the cylinder head cover.
• If piston clearances are adjusted on the head mounted on the engine, do not rotate the crankshaft by pressing hard on the fan blades, as they may break. You should use a screwdriver.

Pushers (with hydraulic clearance adjustment)

Tappets should only be replaced as complete units and cannot be adjusted or repaired. When starting the engine, irregular noise produced by the valves is normal.

Examination

• Maintain the increased speed until the engine reaches operating temperature.
• Increase the rotation speed to 2500 rpm and hold it for approximately 2 minutes. Ensure that the tappets are not the source of the unusual noise. If so, proceed as follows:
• Stop the engine.
• Remove the head cover.
• Turn the crankshaft gear in the direction of engine speed so that the cams working together with the tappet being tested are directed upward.
• Use a wooden or plastic rod to press down on the plunger. If the idle stroke is found to be greater than 0.10 mm, the tappet must be replaced.

Caution! After replacing the tappet, do not start the engine for 30 minutes, as this may cause the piston to hit the valve. Under no circumstances should you attempt to rotate the engine crankshaft using the bolt on the front end of the camshaft, as this may cause damage to the timing belt.

Turn the camshaft (crankshaft if the head is installed on the engine) so that the cams of the cylinder being adjusted are facing upwards. Use a feeler gauge to check the clearance between the tappet adjusting plates and the cams. If the measured clearance is within tolerance, replacement of the tappet adjusting plates is not required.

Valve clearance dimensions

For a warm engine (temperature above 35°C): — inlet valve	0.20-0.30 mm
- exhaust valve	0.40-0.50 mm.
For a cold engine: — inlet valve	0.15-0.25 mm
- exhaust valve	0.35-0.45 mm.

Example:

• If the engine is warm and a 0.25 mm thick feeler gauge can be placed under the intake valve cam, then the clearance is adjusted very well.
• If the thickness of the plate that can be placed under the intake valve cam is within 0.20-0.30 mm, there is no need to replace the tappet adjusting plate.
• For example, if a 0.35 mm thick feeler gauge can be installed, then a 0.10 mm thick adjusting plate should be used. If a max. 0.15 mm, then the adjusting plate should be replaced with a thinner 0.10 mm one.

Caution! If the cylinder head is installed on the engine block, the piston corresponding to the valves whose clearance has been adjusted should not be at TDC. The cams should be facing upward. You need to turn the crankshaft a little to the right and left to close the valves.

Using special tool 2078, press the pusher down and remove the adjusting plate using pliers 12208.



The thickness of the plate is stamped on one of the surfaces. During installation, turn the surface with the marking in the direction of the tappet, i.e. in the opposite direction to the camshaft. The location of the intake and exhaust valves in the head should be determined (figure 2.23), because their working clearances are different.

Attention! After performing head repair (for example, replacing gaskets, camshaft, etc.) be sure to adjust the valve clearance after 1000 km of vehicle mileage.

Table of valve clearance adjustment plates

Thickness (mm)	N details	Thickness (mm)	N details
3,00	056 109 555	3,65	056 109 568
3,05	056 109 556	3,70	056 109 569
3,10	056 109 557	3,75	056 109 570
3,15	056 109 558	3,80	056 109 571
3,20	056 109 559	3,85	056 109 572
3,25	056 109 560	3,90	056 109 573
3,30	056 109 561	3,95	056 109 574
3,35	056 109 562	4,00	056 109 575
3,40	056 109 563	4,05	056 109 576
3,45	056 109 564	4,10	056 109 577
3,50	056 109 565	4,15	056 109 578
3,55	056 109 566	4,20	056 109 579
3,50	056 109 567	4,25	056 109 580