OEM REFERENCE
PARTS CATALOG
OEM part numbers with torque specifications and cross-platform compatibility. Click any part number to copy to clipboard.
| PART NUMBER | DESCRIPTION | TORQUE | NOTES | SHOP |
|---|---|---|---|---|
| 06A 121 012 G |
Water Pump (1.8T)
1.8T AWP • 1.8T AUQ • 2.0 AEG |
15 Nm | Replace with timing belt. Metal impeller version recommended. | AMAZON → |
| 06B 121 111 K |
Thermostat Housing + Thermostat
1.8T AWP • 1.8T AUQ |
10 Nm | Plastic housing cracks. Replace O-ring every time. Opens at 87°C. | AMAZON → |
| 06A 121 133 J |
Coolant Flange / Crack Pipe (Rear)
1.8T AWP • 1.8T AUQ |
10 Nm | Notorious failure point. Upgrade to aluminum aftermarket version. | AMAZON → |
| 059 919 501 A |
Coolant Temperature Sensor (4-Pin Green)
All MK4 |
20 Nm | VW revised this part multiple times. Get latest revision. Affects fuel mixture and fans. | AMAZON → |
| 1J0 121 253 AD |
Radiator (Manual Trans)
Jetta MK4 • Golf MK4 |
N/A | Manual transmission version (no ATF cooler). Verify 1-row vs 2-row for your application. | AMAZON → |
| G 013 A8J M1 |
G13 Coolant Concentrate (1.5L)
All MK4 |
N/A | VW G13 spec. Mix 50/50 with distilled water. Compatible with older G12/G12+. | AMAZON → |
| 1J0 121 207 |
Auxiliary Water Pump (After-Run)
1.8T AWP • 1.8T AUQ |
N/A | Runs after engine shutdown for turbo cooling. Common failure causes overheat after hot shutdown. | AMAZON → |
| 1J0 959 455 K |
Radiator Fan Assembly (Complete)
All MK4 |
N/A | Dual-speed fan. Check fan control module if both speeds fail. Fuse #29 (40A). | AMAZON → |
UPGRADE PATH
ARP HARDWARE
Replace VW stretch bolts with reusable ARP fasteners. Superior clamping force and unlimited reuse.