Check cylinders for leaks

AR01.00-P-1300MNL

Check cylinders for leaks

24.10.2017

Engine

176, 177 in model 217, 222

Shown on engine 176 in model 222

1

Pressure loss tester

 Warning

Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.

Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers.
Wear protective gloves, protective clothing and safety glasses.

AS20.00-Z-0001-01A

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

 Caution

Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil

Wear protective gloves, protective clothing and safety glasses.
Do not fill engine oil into beverage containers.

AS18.00-Z-0001-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A



Remove

1

Warm up engine to normal operating temperature

2

Switch off ignition and store transmitter key outside of transmission range (at least 2 m)

3

Remove corresponding spark plug



AP15.10-P-1580C

4

Remove screw cap of coolant expansion reservoir

5

Take off oil filler cap

6

Attach TDC detection device to the cylinder to be checked

 Commercially available devices/tools
The TDC detection device

7

Remove front and center lower engine compartment paneling

AR61.20-P-1105LF

8

Rotate engine at crankshaft center bolt in direction of engine rotation until piston of cylinder to be checked is at top dead center (ignition TDC)

 Ring wrench

*177589000300

9

Attach TDC detection device to the cylinder to be checked

 Commercially available devices/tools
The TDC detection device

10

Attach pressure loss tester (1) to cylinder to be checked

AR01.00-P-1300-01MNL

 Pressure loss tester

*450589172100

 Screw-in fitting

*270589019100



Check

11

Apply compressed air to cylinder to be checked and read pressure loss from pressure loss tester (1)

Cylinder leakage: permissible loss total indication

*BE01.00-P-1001-02Z

Cylinder leaktightness: Permissible losses at valves and cylinder head gasket

*BE01.00-P-1002-02Z

Cylinder leaktightness: Permissible losses at pistons and piston rings

*BE01.00-P-1003-02Z

If the crankshaft rotates.



Install retaining lock for crankshaft / starter ring gear.

Engine 177 in model 217, 222

AR03.30-P-5001MNM

Engine 176 in model 217, 222

AR03.30-P-5001MNL

12

Check other cylinders in firing order of engine

AR01.00-P-1300-03MM



Install

13

Remove retaining lock

For an installed retaining lock.

Engine 177 in model 217, 222

AR03.30-P-5001MNM

Engine 176 in model 217, 222

AR03.30-P-5001MNL

14

Disconnect pressure loss tester (1)

 Pressure loss tester

*450589172100

15

Remove thread adapter

 Screw-in fitting

*270589019100

16

Install front and center engine compartment paneling

AR61.20-P-1105LF

17

Attach oil filler cap

18

Attach screw cap of coolant expansion reservoir

19

Install spark plugs



AP15.10-P-1580C

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1001-02Z

Cylinder leakage: permissible loss total indication

%

 25

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1002-02Z

Cylinder leaktightness: Permissible losses at valves and cylinder head gasket

%

 10

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1003-02Z

Cylinder leaktightness: Permissible losses at pistons and piston rings

%

 20