Test compression pressure

AR01.00-P-1200V

Test compression pressure

8.3.10

 

Remove/install

Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near the engine as it is running

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

AS00.00-Z-0005-01A

1

Bring engine to operating temperature (approx. 80°C)

 Only test compression pressure when engine is at normal operating temperature.

2

Remove air filter housing

All except model 203.065/265, 170.466: 

Detach the air filter housing from the rubber retainers at the cylinder head covers vertically upward.

 Model 211, 220, 230.475: Unclip engine front end cover.

 Installation: Rub the rubber retainers on the cylinder head covers and sealing ring of the hot film air mass sensor in the air filter housing with lubricant.

Model 230.474, 203.065/265, 170.466

AR09.10-P-1150SVK

Lubricant paste

*BR00.45-Z-1002-06A

3

Remove spark plugs

 Remove only one spark plug per cylinder:



Model 463.209 /232 /233 /244 /245 /250 with engine 112.945

Model 463.206 /240 /241 /247 /248 /249 /254 with engine 113.962

Model 463.243 /246 with engine 113.982

AP15.10-P-1580GA



Model 211, 220, 230.474/475

AP15.10-P-1580AB



Model 210, 208, 203, 202, 170, 129

AP15.10-P-1580A

4.1

Remove key from electronic ignition switch (EIS)

Model 211, 230.474/475

 Vehicles with code (889) Keyless Go: Press the start/stop button repeatedly until the ignition is switched off.

5

Crank engine with starter

 Do not crank engine at steering lock but use contact switch of the compression recorder.

 In order to remove the combustion residue from the cylinders, crank the engine for about 5 seconds with the starter.

All except model 203

AR01.10-P-0110V

Model 203

AR01.10-P-0110PV



Checking

6

Insert compression recorder into spark plug bore

Compression recorder

*001589762100

7

Open throttle valve

Except model 211, 230.474/475

8

Crank engine with starter

 Do not crank engine at steering lock but use contact switch of the compression recorder.

All except model 203

AR01.10-P-0110V

Model 203

AR01.10-P-0110PV

9

Carry out test procedure at remaining cylinders in the same way

10

Compare measurements obtained with the specified pressures

Compression installation tolerance or new value

*BE01.00-P-1001-01D

Compression pressure wear limit or limit value

*BE01.00-P-1002-01D

Compression pressure permissible difference between individual cylinders

*BE01.00-P-1003-01D

If pressure is below the minimum compression pressure or if permissible difference between individual cylinders is exceeded: 

Check cylinders for leaks

AR01.00-P-1300HV

11

Install in the reverse order

Number

Designation

Engine
112.910/
911/912/920/
921/923/940/
941/942/943/
960,
113.940/942/
943/961/963
low compression

Engine
112.910/
911/920/921/
922/923/940/
941/942/943/
944/945/946/947, 113.940/941/942/
943/960/961/962/
963/965/968/969
normal compression

Engine
113.944
Standard compression

BE01.00-P-1001-01D

Compression installation tolerance or new value

bar

10...12

12...14

11...13

BE01.00-P-1002-01D

Compression pressure wear limit or limit value

bar

8.0

9.0

10.0

BE01.00-P-1003-01D

Compression pressure permissible difference between individual cylinders

bar

1.5

1.5

1.5

Number

Designation

Engine
113.980/
981/982/984
Standard compression

Engine 113.987/988/
990/991/993

Engine
113.992/995

BE01.00-P-1001-01D

Compression installation tolerance or new value

bar

11...13

9...12

11...13

BE01.00-P-1002-01D

Compression pressure wear limit or limit value

bar

10.0

8.0

8.0

BE01.00-P-1003-01D

Compression pressure permissible difference between individual cylinders

bar

1.5

1.5

1.5

Number

Designation

Order number

BR00.45-Z-1002-06A

Lubricating paste, rubber parts 2.5 kg, DB supply specification 6867.00

A 000 989 01 60