VW Polo Teardown (Part 1)

Engine compartment and driver's seat area

2014/12/02

Summary

VW Polo
VW Polo being torn down
* Click on the photo for a larger image

 The VW Polo teardown was performed on November 5 and 6, 2014, at the maintenance shop of the Saitama Institute of Automotive Technology (SIAT). The event was co-organized by the Saitama Industrial Development Corporation as well as Next Generation Automobile Industry and Japan Auto Parts Industries Association. Later, on November 19, 2014, the disassembled parts were displayed for public viewing at the Saitama Industrial Technology Center.

 The vehicle used for the teardown was the 2012 model of the British VW Polo fitted with a 1.2-liter diesel engine and not sold in Japan.

 The Polo is one of the smallest among the B-segment cars but is highly rated because of its outstanding driving comfort (performance, spaciousness). It was chosen the European Car of the Year in 2010. It was also chosen the World Car of the Year, the Import Car of the Year Japan, and the RJC Import Car of the Year, all for 2010.

 Reported below is the structure of the engine compartment and the driver's seat area having direct impact on the excellent driving comfort. A list of the car's key parts suppliers is also included.

 The first day was spent for removing the engine and the transmission. The removed engine components were further disassembled in the second day. The interior parts were disassembled after the two-day event and were displayed at the public viewing venue. The disassembled parts of the 1.2-liter gasoline engine (manufactured in 2011 and fitted in the Polo) were also displayed.


Past teardown reports:

Nissan Note (Sep. 2014)
 (Part 1) Major safety technology and advanced driver assistance systems
 (Part 2) Drive unit and supercharger

Honda Accord Hybrid (Feb. 2014)
 (Part 1) Sport Hybrid i-MMD PCU and vehicle chassis components
 (Part 2) SPORT HYBRID i-MMD Battery components and electric servo brake system
 (Part 3) SPORT HYBRID i-MMD drive unit

Honda Fit Hybrid (Dec. 2013)
 (Part 1) Battery components & brake system
 (Part 2) Engine and transmission

Toyota Aqua (Nov. 2012)
 (Part 1) Part suppliers and battery components
 (Part 2) Hybrid systems behind the 35.4km/liter (53 mpg city) car

Nissan Leaf
 (Part 1) Nissan Leaf teardown (Mar. 2012)
 (Part 2) main components disassembled (Sep. 2012)
 (Part 3) body cutaway (Nov. 2012)



Main specifications of VW Polo (2012 British model)

Vehicle VW Polo 2012 British model (right-hand drive)
Dimensions Length: 3,970mm, Width: 1,682mm, Height: 1,462mm, Wheelbase: 2,470mm
Vehicle weight 1,132kg
Fuel efficiency (NEDC) Combined 26.3, Urban 21.7, Extra-urban 30.3 (km/liter)
Diesel engine 1.2-liter inline 3-cylinder (intercooled direct-injection engine,
DOHC 12-valve, compression ratio 16.5, maximum output
55kW(75PS)/4200rpm, maximum torque 180Nm/2000rpm
Transmission 5-speed manual transmission
Price GBP 13,634  (London, U.K.)
Plant name Uitenhage plant, South Africa

Source: Compiled by MarkLines based on "2014 Vehicle Teardown Study Group Data" by the Saitama Industrial Development Corporation, Next Generation Automobile Industry

 

 



Key parts suppliers (104 parts)

 

Part name Supplier Country
Diesel engine components
(1.2-liter inline 3-cylinder DOHC)
Piston MAHLE -
Cylinder head cover India
Cylinder head KS Aluminium-Technologie -
Common rail Bosch -
High-pressure pump for common rail Delphi Romania
Injector -
Engine ECU Hungary
Intake manifold MANN+HUMMEL -
Swirl control valve HELLA -
Turbocharger, exhaust manifold Honeywell -
Starter motor Bosch South Africa
Air-flow meter Germany
Air cleaner -
Air cleaner filter UFI FILTERS Tunisia
Air-conditioning compressor Sanden Poland
Engine belt Mitsuboshi Belting Indonesia
Oil filter, cooler MAHLE Austria
Alternator Valeo -
Clutch cover, disc Turkey
Throttle valve VDO (Continental) -
Timing belt Dayco Italy
Duct (turbocharger to intercooler) ETM Engineering Technologie Marketing Germany
Belt tensioner Litens Automotive Canada
Tensioner bearing Koyo Seiko (JTEKT) Japan
Lead battery VARTA Germany
Fuel filter UFI FILTERS -
Oxidation catalyst EMCON Technologies (Faurecia) -
Wide-range air-fuel ratio sensor NTK Ceramics (NGK Spark Plug) Japan
DPF EMCON Technologies (Faurecia) -
Exhaust gas temperature sensor EPIQ Bulgaria
EGR valve Wahler (BorgWarner) -
Air-conditioning components HVAC system Behr (MAHLE Behr) South Africa
A/C switch Portugal
A/C switch housing PREH (Joyson Group (China)) Portugal
Side ventilator IBER-OLEFF Portugal
Front/center ventilator Portugal
Instrument panel central switches (hazard switch, etc.) TRW Automotive Germany
Safety equipment ESP Bosch -
Driver airbag Takata-Petri S. Africa, Germany
Airbag inflator Takata -
Airbag control unit Bosch Germany
Front passenger airbag TRW Automotive South Africa
Seatbelt South Africa
Brake master cylinder -
Brake booster Ate (Continental) -
Brake pad (front wheel) GALFER -
Horn Clarton Horn Spain
Front-end module Radiator, intercooler Behr (MAHLE Behr) South Africa
Radiator core support Simoldes Plasticos -
Headlight HELLA Czech
Turn signal light -
Fog lamp Slovenia
Fog lamp bulb Osram Germany
Front bumper fascia, front grille Rehau South Africa
Interior and exterior parts Instrument panel Faurecia -
Center console Venture -
Shift lever boot Detlef Bingen -
Audio (for U.K.) Bosch Portugal
Audio (for Japan) BLAUPUNKT Portugal
Key HELLA -
Gauge board VDO Spain
Multimedia interface Mitsumi Germany
License plate lamp CML (Grupo Antolin) -
Light switch TRW Automotive Spain
Side mirror lamp Olsa -
Front inner fender Venture South Africa
Door trim Grupo Antolin South Africa
Trunk interior trim S. Africa (Uitenhage)
Insulator Feltex Automotive (KAP Manufacturing Proprietary/KAP International Holdings) South Africa
Windshield Saint-Gobain Sekurit -
Front door glass Fuyao Glass Industry Group -
Rear side glass -
Rear door glass Armourplate (Shatterprufe) South Africa
Rear gate damper Stabilus Germany
Window regulator motor Bosch Germany
Wiper system South Africa
Wiper motor Germany
Wiper arm Champion (Federal-Mogul Motorparts) -
Other Power steering electrohydraulic pump TRW Automotive -
Power steering oil tank -
Power steering gear -
Tire Continental -
Aluminum wheel BORBET South Africa
Spare tire wheel Podhoran Lukov a.s. -
Fuel pump Continental -

 

1.2-liter inline 4-cylinder SOHC gasoline engine (intercooled direct-injection turbocharger)

Part name Supplier Country
Turbocharger IHI -
Waste gate actuator MAHLE Austria
Air cleaner box UFI Filters Italy
Air cleaner filter China
Ignition NGK (NGK Spark Plug) -
Ignition coil assembly ELDOR Turkey
Air-conditioning compressor Sanden Poland
Air-conditioning compressor piping Bridgestone -
Engine belt Optibelt -
Flywheel LUK (Schaeffler) -
Engine water pump GPM -
Generator Bosch Spain
Starter motor Valeo Poland
Throttle body Magneti Marelli -
Crankshaft bearing Zhejiang FKG Precision Machinery Germany
Air-flow meter Bosch Germany
Knock control sensor Siemens -
Air-intake duct ETM Engineering Technologie Marketing Germany
Belt idler pulley Litens Automotive Canada

(Note) The gasoline engine was manufactured in 2011.

 

 



Before disassembly

 

VW Polo before teardown 1 VW Polo before teardown 2
This report mainly introduces components that have direct impact on the highly reputed quietness, riding comfort and handling of the VW Polo. Such components include the engine and transmission mounts, steering members, and seat-rail fixtures. The engine and the suspension will be introduced in a separate report.

 

 



Engine compartment: Front-end module and engine mounts

 

Engine compartment layout
Engine compartment layout 1 Engine compartment layout 2
Photos show the engine compartment with the engine cover removed. The engine air intake components are located at the front of the vehicle and the exhaust gas components are placed at the rear. The variable nozzle turbocharger is fitted to the cylinder head via the exhaust manifold which is integrated with the turbo housing. The turbocharger is located between the engine and the dashboard. The oxidation catalyst is located directly behind the turbocharger. The diesel turbocharger engine is air-cooled by an intercooler and naturally has many ducts and pipes coming in and out. However, they are laid out in a sensible manner.

 

Front-end module

Front-end module

Front-end module with all associated components

Front-end module

Front-end module being removed

Front-end module

Back of front-end module

The front-end module contains the radiator, air-conditioning condenser, air-cooled intercooler and headlamps that are assembled to the plastic radiator core support and the front bumper reinforcement. The sub-assembly is then fitted to the front end of the engine compartment. The right-hand photo shows the front-end module separated from the engine compartment after the headlamps are removed first. The front-end module is easily separated from the engine compartment to make space for easier engine disassembly.

 

Engine mounts
The diesel-fueled VW Polo is one of the quietest among the B-segment vehicles. Other than the noise and vibration suppressing designs of the engine itself, the engine mounts are also designed to reduce vibrations.
Engine mounts Engine mounts
The engine and the transmission are normally hoisted upward. For the purpose of teardown study, the front suspension member and the undercover were removed first and the engine and transmission are lowered to the floor.
Engine 1 Engine 2
The engine mounts are placed at the sections where vibrations of the engine and the transmission are minimized.

Right-side of the engine compartment

Right-side of the engine compartment

Left-side of the engine compartment

Left-side of the engine compartment

The side members form the main structural frame of the engine compartment. It is subjected to collision impact from the front bumper, the engine vibration from the engine mounts and suspension impact and vibration from the suspension members. The side members must be stiff enough to withstand those impacts and vibrations. This need is accomplished by minimizing the offset from each input point and connecting such points with smoothly curved lines. The strut housing is located near the dashboard and the right- and left-side strut housings are joined by the cowl top front panels. This efficiently provides a rigid structure (the cowl top front panels are removed in the photo). The right- and left-side engine mounts are located with a minimum offset from the side members to reduce the transmission of vibrations.

Right-side engine mounting

Right-side engine mount installed to the side member

Right-side engine mount

Right-side engine mount

A hydraulic engine mount is used in the right side which is subjected to larger load and vibrations from the engine.

Left-side engine

Left-side engine (transmission) mount installed to the side member

Left-side engine

Left-side engine (transmission) mount

A rigid engine (transmission) mount is used in the left side. The transmission bracket joins the bottom of the aluminum bracket extending from the center of the engine mount rubber.

 

 



Driver's seat area

 

Steering member to body fixture
Steering vibration when the engine is idling especially in diesel powered vehicle or during high-speed driving is often difficult issue. Special considerations are incorporated to increase the support stiffness of the steering column and reduce steering vibration. This is achieved by ensuring enough stiffness of the steering member that supports the steering column and of the steering member to the body fixture. It must be noted, however, many vehicles today have a single straight member that spans across the right and left A-pillars. The VW Polo has two steel pipes that are welded together at the center and joined with an offset.
Steering member A-pillar
The pipe in the driver's side has a large diameter and is connected to the steering column with a smaller offset. This helps to increase the support stiffness of the steering column. The steering member is joined with the A-pillar via a bracket having a sufficiently large cross-section. This helps to increase the fixture stiffness. The steering member fixture is designed to absorb the tolerance of dimensional tolerance between the right- and left-sides of the vehicle. (The dimension between the right and left A-pillars fluctuate by dimensional tolerance of the floor, roof and many other parts. This leads to a large variation in the dimensions between two locating holes on the mounting brackets placed at the right and left-side end of the body. These holes in the brackets are used to mount the steering member to the A-pillars. This dimensional tolerance is absorbed by using horizontally elongated holes in the left side A-pillar bracket.)
The steering member pipe The left-side A-pillar
The steering member pipe in the driver's side is joined with the left-side pipe at the center console via a floor stay. Two straight pipes are used in the right and left to ensure sufficient stiffness. The left-side A-pillar has an identical structure as in the right-side A-pillar to ensure high fixture stiffness. Elongated holes are used to absorb dimensional dispersion.

 

Seat fixture in the front floor
seat-rails seat-rails
The seat sits on seat-rails with a wider distance in between to provide large space under the front seat cushion. This provides large foot space for the backseat occupant. The seat-rail fixture member is located at the corner of the floor and the tunnel, the point whose rigidy is very high. A simple rail structure further ensures sufficient stiffness.
seat-rail fixture members Seat-side seat-rail structure
The seat-rail fixture members of a simple design are fitted along the side sill and floor tunnel. The tunnel-side member is free of catalyst or other protrusions. Both the tunnel-side and the sill-side members are straight in shape so that sufficient stiffness can be attained easily. Seat-side seat-rail structure. A manual seat is used but it has a lift-up function.

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