Table of contents: Engines "DR" and "DS" produced… ↓ Engines "DS" produced since… ↓
Engines "DR" and "DS" produced before September
Examination
Warm up the engine to operating temperature (coolant temperature above +35°C, cylinder head warm).
Disconnect the fuel hose, close the holes with plugs. Remove the cylinder head cover.
Turn the crankshaft by the pulley mounting bolt, successively bringing each camshaft cam with the back part to the end of the tappet and measuring the gap between the back of the cam and the adjusting washer on the valve tappet using a set of feeler gauges.
Warning: It is not recommended to turn the camshaft directly by the pulley mounting bolt, so as not to damage the timing belt.
Clearances in the valve drive mechanism
The clearance between the camshaft cams and the adjusting washers on a warm engine should be 0.25±0.05 mm for the intake valves and 0.45±0.05 mm for the exhaust valves, on a cold engine 0.20±0.05 and 0.40±0.05 mm, respectively.
Adjustment
Perform the first valve clearance adjustment after disassembling the mechanism on a cold engine. Adjust the clearances if you find deviations from the permissible values during the check.
Record the clearance values 3i for each valve.
Adjusting clearances in the valve drive mechanism. Checking the clearance between the back of the cam and the adjusting washer on the end of the tappet
Set the valve of one of the cylinders (No. 1, 3, 4 or 2) to the position of maximum clearance between the cam and the adjusting washer, thus relieving the tappets of the opposite cylinder (No. 4, 2, 1, 3), adjust the clearance.
Removing the adjusting washer using the VW 546 tool and the 10 208 puller
Using the VW 546 tool, press the inlet and outlet valve tappets into the cylinder head. Rotate the tappet slot perpendicular to the camshaft axis and use the special puller 10-208 to remove the valve adjusting washer.
Measure the thickness T of the removed washer with a micrometer and calculate the thickness of the new washer using the formula:
Tn=T+Zi-Zn,
where:
Tn - thickness of the new washer;
T — thickness of the removed washer;
Zi - measured gap;
Zn — nominal clearance.
* Select a washer of the required thickness and install it on the pusher with the mark towards the pusher.
Remove tool VW 546.
Adjust the clearances for the remaining valves in the same manner.
Make final adjustments to valve clearances on a warm engine if the initial adjustments were made on a cold engine.
Engines "DS" produced since September 1985 and "NP"
The valve drive mechanism of the DS model engines produced since September 1985 and the NP model uses hydraulic tappets, which provide automatic compensation of valve clearances.
[Information obtained from this resource: AudiManual.ru]