Engine Pressure Loss, Check
Bring engine to operating temperature: oil temperature > 80° C/176 °F.
Disconnect battery ground cable.
Remove spark plug connector.
Remove spark plugs.
Remove oil dipstick.
Unscrew oil filler cover and cover from coolant compensation tank.
Remove distributor cap.
| Position piston of 1st cylinder at TDC. Distributor rotor arm must align with notched mark on edge of ignition distributor housing. | |||
|---|---|---|---|
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Connect pressure loss tester to available compressed air system (pressure 400 to 1600 kPa, 4 to 16 bar, 58 to 232 psi) and connect checking nozzle (1).
Bring pointer to "cal" marking by turning knurled bolt (2).
| Disconnect checking nozzle. | |||
|---|---|---|---|
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Screw connection hose to ignition plug bore of cylinder 1 and connect to compression loss tester.
Important:
When doing this, the crankshaft must not rotate.
If the crankshaft has rotated, disconnect connection pipe from tester, correct crankshaft position and reconnect connection hose.
Read compression loss in percent from tester.
Check by listening whether air is escaping through intake manifold, exhaust, crankcase or oil intake connections.
Check for bubble formation in coolant compensation tank.
The total compression loss per cylinder should not exceed 25%.
| The difference between the individual cylinders should not exceed 10%. | |||
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Checking of the remaining cylinders occurs analogously.
Turn crankshaft until next piston is at TDC.
Ignition sequence: 1 5 3 6 2 4
| Make marks on distributor housing for assistance. | |||
|---|---|---|---|
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Remove pressure loss tester.
Install spark plugs - torque 40 Nm/29.5 lbf. ft.
Connect spark plug connection and route ignition cable free of tension.
Attach distributor cap, oil dipstick, oil filler cover and cover for coolant
compensation tank.
Connect battery.
Check ground connection for good condition and firm seat.