03G 103 603 AD Oil Pan Fits Audi A3 Volkswagen Golf Skoda And Other Models

03G 103 603 AD Oil Pan: Applicable Models, Years, Displacement & Function Analysis

   I. Precise Applicable Models & Technical Parameters
  Part Number Interpretation
   03G: Exclusive prefix for diesel engine parts of the Volkswagen Group, mainly applicable to the group’s EA189 series diesel engines. It is a key identifier to distinguish between petrol and diesel parts.
   AD: Represents the part version suffix, corresponding to high-strength stamped steel material (some batches use lightweight aluminum alloy). It is specifically designed for the high-torque output characteristics of diesel engines to enhance impact resistance and vibration resistance.
Core Applicable Scope
   1. Audi
   Model: Audi A3, corresponding to chassis code 8P, with production years covering 2005–2013
   Engine Models: Compatible with 2.0 TDI engines (specific models: CBAB, CRCA)
  Displacement & Power: 2.0L displacement, maximum power 140–170 PS, maximum torque 320–350 N・m, including front-wheel drive and quattro all-wheel drive versions.
   2. Volkswagen
  Volkswagen Golf V: Chassis code 1K, production years 2003–2008, compatible with 2.0 TDI engines (models: BKD, BMM), 2.0L displacement, maximum power 140 PS, maximum torque 320 N・m, including Golf Variant (estate version);
  Volkswagen Golf VI: Chassis code 5K, production years 2008–2014, compatible with 2.0 TDI engines (models: CRHC, CRHD), 2.0L displacement, maximum power 140–170 PS, maximum torque 320–350 N・m, also covering estate versions.
   3. Skoda
   Skoda Octavia II: Chassis code 1Z, production years 2004–2012, compatible with 2.0 TDI engines (models: BMM, CBAB), 2.0L displacement, maximum power 140 PS, maximum torque 320 N・m, including Octavia Combi (estate version).
   4. Seat
   Seat León II: Chassis code 1P, production years 2005–2012, compatible with 2.0 TDI engines (models: BKD, CBAB), 2.0L displacement, maximum power 140 PS, maximum torque 320 N・m.
Excluded Applicable Models
   Petrol engine models: Such as Volkswagen 1.4 TSI, 1.8 TSI, Audi 2.0 TFSI, etc. The oil pan interface size and oil circuit layout of these models are completely different from those of diesel versions. Forced installation will cause engine oil leakage or lubrication failure;
   Hybrid/electric models: Such as Audi A3 e-tron, Volkswagen Golf GTE. Their cooling system layouts are significantly different from those of traditional diesel vehicles, so there is no need to install this oil pan;
   Rear-wheel drive/longitudinally mounted engine models: Such as Audi A4 B8, Volkswagen Passat B7. These models adopt a longitudinally mounted engine layout, and the shape and fixing points of the oil pan are incompatible with models on the PQ35/PQ46 platform with transversely mounted engines.
Special Note
Some early models produced between 2003–2005 (e.g., Volkswagen Golf V) may be equipped with 1.9 TDI engines (models ALH, PD series). For such models, additional precise verification is required through the 10th digit of the vehicle VIN (year code) and engine model (e.g., ALH, BKD) to avoid confusion with parts for 2.0 TDI models.
   II. Core Functions & Technical Characteristics
   1. Diesel Engine-Specific Structural Design
  High-strength impact-resistant material: Aimed at the high-torque output of diesel engines (the peak torque of 2.0 TDI can reach 350 N・m), it is made of double-layer stamped steel or lightweight aluminum alloy with a material thickness of 1.8–2.5 mm. It can withstand engine vibration and chassis impact for a long time to prevent oil pan deformation;
  Deep oil sump capacity design: The oil sump capacity is 15–20% larger than that of petrol engine oil pans on the same platform, approximately 5.5–6.5 L. This ensures that the oil pump can always suck in sufficient engine oil when the vehicle is subject to off-road bumps or sudden acceleration, preventing lubrication failure caused by insufficient engine oil supply (especially suitable for the high lubrication needs of turbochargers).
   2. Thermal Management & Noise Reduction Optimization
   Integrated engine oil cooling channel: Some batches of oil pans have built-in independent cooling pipelines, which can work in coordination with the engine coolant system to reduce the engine oil temperature by 8–12℃. This effectively alleviates the aging problem of turbochargers caused by high temperatures and extends the turbocharger overhaul cycle by 20%;
   Honeycomb-shaped energy-absorbing inner wall: A honeycomb structure is formed on the inner wall of the oil pan through a special stamping process, which can absorb vibration waves generated during engine operation, reduce the transmission of vibration to the vehicle body, and lower the in-vehicle noise by 2–3 dB(A) (the effect is particularly obvious at idle speed and low-speed driving).
   3. Filtration & Sealing Protection System
  Magnetic oil drain plug: A standard M14×1.5 specification magnetic oil drain plug (original equipment (OE) part number: N 902 247 01) is provided. The strong magnet at the head of the plug can absorb metal debris (such as iron filings generated by engine wear) in the engine oil, with a filtration efficiency of 92%, reducing the risk of clogging of the oil pump and oil passages by debris;
   Temperature-resistant sealing assembly: When installing, it is necessary to match the original rubber-metal composite sealing ring (part number: 03G 103 601). The sealing ring is made of fluorosilicone rubber material with a temperature resistance range covering -40℃ to 150℃. This ensures no engine oil leakage from the oil pan within 100,000 kilometers under extreme temperature difference environments.
   III. Key Roles in the Vehicle
  1. Core Hub of the Lubrication System
  Oil storage and supply guarantee: As the main storage container for engine lubricating oil, the oil pan stably delivers engine oil to the oil pump through the built-in oil strainer, and then the oil pump distributes the oil to key friction pairs such as the crankshaft, connecting rods, and turbocharger. It ensures that the engine oil pressure reaches 2.5 bar within 2 seconds during cold start, meeting the immediate lubrication needs of the engine;
   Impurity sedimentation and purification: The bottom of the oil pan adopts a 12° inclined design, which promotes the sedimentation of metal debris and impurities in the engine oil near the oil drain plug. Combined with the adsorption effect of the magnetic oil drain plug, it reduces the wear of internal engine parts caused by impurities circulating with the engine oil.
   2. Protective Barrier for Power Transmission
  Torsion resistance support and structural reinforcement: It is rigidly connected to the engine block through 6–8 high-strength bolts, which can withstand the combustion pressure of diesel engines during operation (the peak pressure can reach 180 bar), reduce the displacement of the engine during operation, and lower power transmission loss;
   Corrosion protection and durability guarantee: The surface of the oil pan undergoes double treatment of electrophoretic coating (coating thickness 20–25 μm) and galvanizing, which can resist corrosion from road deicing agents and ethylene glycol coolant. Its service life can reach more than 15 years in humid or salty environments.
   3. Adaptability to Complex Working Conditions
  Adaptability to off-road scenarios: The minimum height of the oil pan from the ground is designed to be 150–180 mm. Combined with the edge reinforcement rib structure, it can withstand a lateral impact of 100 N・m (such as bumps when passing over rough roads) to prevent oil pan damage;
  Stability in high-load scenarios: During high-load working conditions such as track driving and high-speed cruising, the deep oil sump design can prevent "oil starvation" caused by severe sloshing of engine oil, ensuring continuous lubrication of components such as turbochargers and crankshafts, and avoiding overheating damage caused by insufficient lubrication.
   IV. Verification & Maintenance Recommendations
  1. Precise Matching Steps
• First, check the vehicle VIN, enter the chassis number in the Volkswagen Audi ETKA electronic parts catalog to obtain the oil pan assembly diagram of the corresponding model, and verify whether the part number is 03G 103 603 AD;
• Second, check the engine model. For example, for Audi A3 8P models, it is necessary to confirm that the specific model of the 2.0 TDI engine is CBAB (2009–2013 models) or CRCA (2011–2013 models) to avoid mistakenly installing the oil pan of the early BKD engine.
  2. Replacement & Maintenance Key Points
  Bolt torque control: When installing, a torque wrench must be used to tighten the oil pan bolts in phases according to the standard of "25 N・m pre-tightening + 90° angle turn". This avoids oil pan deformation caused by excessive torque or leakage caused by insufficient torque;
  Synchronous replacement of components: When replacing the oil pan, it is recommended to simultaneously replace the engine oil filter (OE part number: 03G 115 561 B) and the oil cooler gasket (part number: 03G 121 115), and thoroughly clean the residual impurities inside the oil pan;
  Part selection principle: Priority should be given to original parts marked with "OE 03G 103 603 AD". Aftermarket parts may have interface tolerances (exceeding 0.5 mm) or insufficient material strength, which are prone to short-term oil leakage or damage.
  3. Fault Warning Signals
  When the oil pan malfunctions, the vehicle will show obvious signals: such as the engine oil level warning light illuminating (indicating engine oil leakage), a rattling noise from the engine during operation (insufficient engine oil inside the oil pan, causing the oil pump to draw in air), and engine oil dripping traces under the chassis. If such situations are found, immediate inspection is required to avoid severe engine damage caused by lubrication failure.