SsangYong: Engine Euro 4. Manual - part 38

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

3

1990

SWITCHABLE ENGINE MOUNT

D27DTP/D27DT (EU4)  SM - 2006.08

D27DTP/D27DT (EU4)

ENGINE

FUEL

I

N

T

AKE

EXHAUST

PRE-HEA

TING

LUB

COOLING

SWITCHABLE

ECU

DIAGNOSIS

4. OPERATING CONDITION

Vacuum blocked 

→ OFF mode

Engine rpm < 1,000 rpm, vehicle speed < 5 km/h

Vacuum connected 

→ ON mode

Engine rpm > 1,200 rpm, vehicle speed > 10 km/h

2. FUNCTIONS

The switchable engine mount not only supports the engine on the vehicle body, but also has the following
functions:

1. It insulates the vibration during engine running and minimizes the noise and vibration of the en-

gine transferred to the vehicle.

2. It controls the displacement during shifting, sudden acceleration, abrupt braking or cornering to

keep the engine stable.

3. CHARACTERISTICS AND PERFORMANCE

1. The engine mounting can be set to the soft mode to minimize the noise and vibration of engine transferred to

the vehicle when the engine is at idle or low speed while driving.

2. The engine mounting can be set to the hard mode to keep the engine stable from the displacement occurred

by poor road condition, shifting, acceleration and braking under normal driving conditions.

3. The common engine mounting cannot satisfy both of the above characteristics. Therefore, it is set to compro-

mise both characteristics and its performance is decreased. However, the electrically controlled switchable
engine mounting can switch the operating mode of the engine mounting between soft and hard mode accord-
ing to the vehicle speed and engine rpm so that both characteristics are satisfied.

4. The engine mounting is switched between the soft mode and the hard mode to change the damping condition

and spring characteristics.

The orifice is opened to apply the atmospheric pressure so that the shoft rubber
mounting’s characteristic is performed for lowering the damping and spring
characteristics.

The orifice is closed to block the atmospheric pressure and generate the vacuum
state so that the shoft rubber mounting is damped greatly. In this mode, the
rattling of the engine is minimized so that the vehicle’s stability is ensured during
driving, cornering and braking.

Soft  Mode:

Hard Mode:

Soft Mode:

Hard Mode:

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

4

1990

SWITCHABLE ENGINE MOUNT

D27DTP/D27DT (EU4)  SM - 2006.08

D27DTP/D27DT (EU4)

Notes: Description for Engine Mounting System

• The engine mounting fixes the engine on the vehicle body. It minimizes the noise and vibration

of the engine transferred to the vehicle and keep the engine stable during shifting, sudden
acceleration, abrupt braking or cornering.

• When the vehicle is rolling, the engine and the vehicle body may be rattled separately and the

vehicle's stability and handling get poor.

• The engine mounting can be designed as a hard structure to prevent this, but it may cause the

noise and vibration because it cannot insulate its vibration.

• When the vibration with large amplitude is transferred to the vehicle body due to the road

conditions (ex: driving on rough road), the vibration from the vehicle is transferred to the engine.

• This phenomenon is similiar to the case when you run carrying a back pack on your shoulder. If

the back pack is sticked to your back, your running gets stable. However, if the back pack moves
from side to side, your running gets unstable.

• The suspension system uses the spring and shock absorber. If the spring is soft, the vehicle is

stable, but the vibration from the road surface is directly transferred to the vehicle's occupants.
If there is no shock absorber, the vehicle continues to rattle once the vehicle crosses over a
bump on the road. With the shock absorber, the vehicle returns to its stable condition after the
impact from the road surface. These are why the spring and shock absorber are used.

• The hydraulic engine mounting is designed based on these principles. When the vibration with

small amplitude is occurred to the engine, it insulates the vibration smoothly. When the vibra-
tion with large amplitude is occurred, it holds the engine to keep it stable.

• Simply, the small vibration should be insulated softly and the large vibration should be insu-

lated hardly for the optimal performance. The rubber mounting has its own limit, but the hydrau-
lic mounting can satisfy both conditions. To separate these distinct conditions, the modes should
be switched depending on the situation.

• The switchable engine mounting system can be switched between two modes by the engine

ECU depending on the situation to cope with both conditions.

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

5

1990

SWITCHABLE ENGINE MOUNT

D27DTP/D27DT (EU4)  SM - 2006.08

D27DTP/D27DT (EU4)

ENGINE

FUEL

I

N

T

AKE

EXHAUST

PRE-HEA

TING

LUB

COOLING

SWITCHABLE

ECU

DIAGNOSIS

Rubber plate

Switchable engine
mounting assembly

Vacuum port

Fluid filler

5. REMOVAL AND INSTALLATION OF SWITCHABLE ENGINE MOUNT

Structure of Switchable Engine Mount

Removal and Installation of Switchable Engine Mount

For the vehicle equipped with the D27DTP (POWER UP) engine, the installation/removal procedures
of the switchable engine mount are different.

Location

RH

LH

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

6

1990

SWITCHABLE ENGINE MOUNT

D27DTP/D27DT (EU4)  SM - 2006.08

D27DTP/D27DT (EU4)

Switchable Engine Mount (LH)

Ú

Ú

Ú

Ú

Ú Preceding Work: Perform the EAS ECU LOCK in

the EAS air discharge mode us-
ing SCAN-100.

1. Unscrew the engine bracket mounting bolts.

2. Disconnect the vacuum hose of the switchable en-

gine mount under the vehicle.

3. Lift the vehicle and unscrew two mounting bolts of

the switchable engine mount bracket.

4. Lift the engine assembly a little with auxiliary lift so

that the engine bracket and the switchable engine
mount are separated. Remove the engine mounting
adapter and the switchable engine mount at a time.

Engine

bracket

Frame (switchable

engine mounting side)