TDI are a series of turbocharged direct injection diesel engines that are manufactured by the Volkswagen Group. They first appeared in the Audi 100 C3 in 1989. Almost every Volkswagen, Seat, Audi– and Škoda model is nowadays equipped with these engines. They are also used in a number of models from Ford, Volvo, Mitsubishi, Chrysler and some other brands.
The characteristics of TDI engines
TDI engines are equipped with an aluminum or cast iron cylinder block. The cylinder heads are made of aluminum. A belt is commonly used in the valve timing mechanism, although there are versions that use a chain or gear. Depending on the engine version, the fuel system has a high-pressure pump, injectors or a fuel rail. A variable geometry turbocharger is installed in many vehicles as a replacement for a conventional one. There are also twin turbos, some of which are called BiTDI.
Popular TDI engines
| Engine series | Displacement, l | Index | Number of cylinders | Number of valves | Max. Power, hp | Max. Torque, Nm | Injection | Year of manufacture | Applicable models |
| EA381 | 2.5 | 1T | Line 5 | 10 | 120 | 265 | Direct injection | 1989 | Audi 100 C3 |
| EA153 | 2.5 | BAC | Line 5 | 10 | 174 | 400 | Injectors | 2003 | Volkswagen Touareg 1 |
| 5.0 | AJS | V10 | 20 | 313 | 750 | Injectors | 2002 | Volkswagen Phaeton 1 | |
| EA180 | 1.9 | AFN | Line 4 | 8 | 110 | 235 | Direct injection | 1996 | Volkswagen Golf 3; SEAT Cordoba 1; Volkswagen Vento 1; Audi A6 C5; Volkswagen Passat B4; Volkswagen Passat B5; SEAT Ibiza 2; Volkswagen Polo 3; SEAT Toledo 1; Volkswagen Sharan 1; Audi A4 B5 |
| EA188 | 1.9 | AWX | Line engine 4 | 8 | 130 | 285 | Injectors | 2000 | Audi A4 B6; Audi A6 C6; Skoda Superb 1; Volkswagen Passat B5 |
| 2.0 | BMM | Line 4 | 8 | 140 | 320 | Injectors | 2004 | Audi A3 8P; Skoda Octavia 2; Volkswagen Caddy 3; SEAT Altea 1; Volkswagen Golf 5; Volkswagen Jetta 5; SEAT Leon 2; Volkswagen Touran 1 | |
| EA189 | 1.6 | CAYC | Line engine 4 | 16 | 105 | 250 | Common rail | 2009 | Škoda Rapid 1; Audi A3 8P; SEAT Ibiza 4; Volkswagen Passat B7; Skoda Octavia 2; SEAT Leon 2; Skoda Yeti; Volkswagen Golf 6; Skoda Superb 2; Volkswagen Jetta 5 |
| 1.9 | CAAC | Line 4 | 16 | 140 | 340 | Common rail | 2009 | Volkswagen Multivan T5; Volkswagen Caravelle T5; Volkswagen Transporter T5 | |
| EA288 | 1.6 | DCXA | Line engine 4 | 16 | 120 | 250 | Common rail | 2014 | Škoda Superb 3; Volkswagen Passat B8 |
| 2.0 | DBGC | Line 4 | 16 | 150 | 340 | Common rail | 2016 | Škoda Kodiaq 1; Volkswagen Tiguan 2 | |
| EA330 | 2.5 | BDH | V6 | 24 | 180 | 370 | Direct injection | 2004 | Audi A6 C5; Volkswagen Passat B5; Audi A4 B6 Convertible |
| EA381 | 2.5 | BJK | Line engine 5 | 10 | 109 | 285 | Common rail | 2006 | Volkswagen Crafter 1 |
| EA896 | 3.0 | CASA | V6 | 24 | 240 | 550 | Common rail | 2007 | Volkswagen Touareg 1; Audi Q7 4L |
| EA897 | 3.0 | CRCA | V6 | 24 | 245 | 550 | Common rail | 2010 | Volkswagen Touareg 2; Audi Q7 4L |
| EA898 | 4.2 | CKDA | V8 | 32 | 340 | 800 | Common rail | 2010 | Volkswagen Touareg 2 |
Frequent defects of TDI engines
| Defects | Engines |
| The electronically controlled high-pressure pump must be adjusted regularly. | 1T; BDH |
| If the engine overheats due to malfunctions in the cooling system, the cylinder head may deform. | 1T |
| The intake manifold is prone to cracking. | BAC |
| The seals of the injectors and the tandem pump will leak over time. | AJS; AWX; BAC |
| The gears of the valve timing mechanism wear out quickly. | AJS |
| The valve seats burn out with high mileage, resulting in lower compression of the engine. | AFN |
| The turbine wheels or the EGR valve can occasionally get stuck . | AFN; AWX; CAAC; BDH; BMM |
| Using an inferior oil will cause camshaft lobes or hydraulic valve lifters to wear out quickly. | AWX; BJK |
| The piezo injectors often fail. | BMM; CAYC; BJK; CKDA; CRCA; CASA; CAAC |
| Injector fasteners are loosening and causing leaks. | BMM |
| Under the valve cover leaks are common. | BDH; CAYC |
| The diesel particulate filter clogs relatively quickly. | CAAC; DBGC; CKDA; CRCA; CASA; CAYC |
| Often the seal of the heat exchanger dries out, causing coolant to leak out. | DCXA |
| The Intake manifold swirl flaps bind over time. | CASA |