Check cylinders for leaks

AR01.00-P-1300MRK

Check cylinders for leaks

24.02.2020

Engine

264, 274 in model 167

Shown on engine 264

1

Pressure loss tester

 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

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

 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

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A



Remove

 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

1

Warm up engine to normal operating temperature and switch it off.

 Only check cylinder leakage when the engine is at normal operating temperature.

2

Switch off ignition and store transmitter key outside of transmitter range (min. 2 m).

3

Remove spark plugs.



Engine 264 in model 167

AP15.10-P-1580MCU



Engine 274 in model 167

AP15.10-P-1580CWF

 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

4

Slowly open cap of coolant expansion reservoir, release overpressure and unscrew.

5

Unscrew oil filler cap.

6.1

Remove right charge air line and charge air cooler, attach with connected lines on vehicle so that free of tension and secure against falling down.

Engine 264 in model 167

AR09.41-P-6817MRK


Do not crush or kink or subject lines to tension.
This would lead to damage to the lines and can impair their function.

6.2

Remove engine air intake duct upstream of air filter.

Engine 274 in model 167

7

Attach TDC detection device to the cylinder to be checked.

 Commercially available devices/tools
The TDC detection device

8

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

 The piston of the cylinder to be checked must be at ignition TDC.

 Socket wrench bit

*001589650900

9

Remove TDC detection device from cylinder to be checked.

10

Connect pressure loss tester(1) at cylinder to be checked.

AR01.00-P-1300-01VA

 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

 Pressure loss tester

*450589172100

If the crankshaft rotates:



Install retaining lock for crankshaft.

AR03.30-P-5001MRK



Install

12

Remove retaining lock.

For an installed retaining lock.

AR03.30-P-5001MRK

13

Disconnect pressure loss tester(1).

14.1

Install charge air cooler and right charge air line.

Engine 264 in model 167

AR09.41-P-6817MRK

14.2

Install engine air intake duct upstream of air filter.

Engine 274 in model 167

15

Screw on oil filler cap.

16

Screw on cap of coolant expansion reservoir.

17

Install spark plugs.



Engine 264 in model 167

AP15.10-P-1580MCU



Engine 274 in model 167

AP15.10-P-1580CWF

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