In the early 2000s, VAG concern widely introduced diesel power units with fuel system based on pump-nozzles. In the range of engines were units with a volume from 1.2 to 5 liters.
On our site you can find an article about one of the first 1.9 TDI engines with pump-jets. In this article we will tell you about one of the younger engines, which was installed on many subcompact models of VAG cars.
Before the appearance of 1.2 and 1.4 TDI engines, VAG concern never had 3-cylinder units (after them, there were no 3-cylinder diesels, but the 3-cylinder motor 1.0 TSI appeared in 2015). For reference, we note that in early 2014, a 2-cylinder diesel with a working volume of 0.8 liter appeared on the small-series hybrid VW XL1.
Technical specifications
| Characteristics | Value |
|---|---|
| Exact volume | 1422 cm³ |
| Power system | nozzle pump |
| Engine power | 75 – 90 hp |
| Torque | 155 – 230 Nm |
| Cylinder block | cast iron R3 |
| Cylinder head | aluminum 6v |
| Cylinder diameter | 79.5 mm |
| Piston stroke | 95.5 mm |
| Compression ratio | 19.5 |
| Engine features | balanced shaft |
| Hydrocompensators | yes |
| Transmission timing | belt |
| Fasor regulator | no |
| Turbocharger | VGT |
| What oil to use | 4.3 liters 5W-30 |
| Fuel type | diesel |
| Environmental class | Euro 3/4 |
| Example service life | 250,000 km |
Engine Modifications (1999 – 2010)
| Model | Power | Torque | Application |
|---|---|---|---|
| AMF | 75 hp | 195 Nm | Audi A2 1 (8Z), VW Lupo 1 (6X), Polo 4 (9N) |
| ATL | 90 hp | 230 Nm | Audi A2 1 (8Z), VW Polo 3 (6N) |
| BAY | 75 hp | 195 Nm | VW Polo 4 (9N), Seat Ibiza 3 (6L) |
| BHC | 75 hp | 195 Nm | only Audi A2 1 (8Z) |
| BMS | 80 hp | 195 Nm | VW Polo 4 (9N), Skoda Fabia 2 (5J), Roomster 1 (5J) |
| BNM | 70 hp | 155 Nm | Skoda Fabia 1 (6Y), Fabia 2 (5J), Roomster 1 (5J) |
| BNV | 80 hp | 195 Nm | Skoda Fabia 1 (6Y), Fabia 2 (5J), Roomster 1 (5J) |
| BWB | 70 hp | 155 Nm | only VW Polo 4 (9N) |
Design features of the 1.4 TDI engine
The 3-cylinder turbodiesel 1.4 TDI belongs to the EA 188 diesel family and was created on the basis of the 1.9 TDI engine after the “separation” of one cylinder. It sounds simple, but there are plenty of complexities. The thing is that on the crankshaft of a 3-cylinder motor you have to arrange the cranks in 120 degrees (divide 360° by 3 – we get 120°). Immediately there are problems with balancing and moments of inertia that arise with a 3-cylinder engine. On such a motor, the pistons do not move in counter-phase as they do with a 4-cylinder crankshaft. Again, on a 3-cylinder engine, the compression and ignition cycles occur through those rather large angles, which again introduces imbalance into its operation. Due to the unbalanced moments of inertia of a 3-cylinder engine, the crankshaft experiences radial runout and oscillations relative to the transverse axis.
For this reason, the 1.4 TDI 3-cylinder engine simply cannot do without a complex system of balancers and counterweights. And it is impossible to fit all the balancers in a relatively compact crankcase. Therefore, the 1.4 TDI balancers are located in the dual-mass flywheel, on the crankshaft pulley. In the crankcase itself is a balancer shaft with a pair of counterweights working “in tandem” with the two counterweights on the crankshaft. You got it right – there are only two counterweights on the 3-cylinder crankshaft, on the 1st and 3rd cranks.
To realize an injection pressure of 2000 bar, the timing drive uses a 30mm wide timing belt. The toothed crankshaft pulley incorporates an inertia damper to reduce vibration loads. In addition, the crankshaft pulley is also composite: outside – a toothed crown, inside – a hub, sitting on the tapered shank of the camshaft.
However, with such complexities and nuances of design, the engine 1.4 TDI turned out to be quite strong, although inherited some diseases inherent in the engine 1.9 TDI.
Problems and reliability of the 1.4 TDI engine
The block of the 3-cylinder diesel engine 1.4 TDI made of gray cast iron is repairable, unlike the aluminum block of the engine 1.2 TDI, which deforms already at loosening of bolts of crankshaft beds.
In the aluminum cylinder-head of the engine 1.4 TDI installed, as well as on the engine 1.9 TDI pump-jets, each of which is attached to one pressure plate, fixed by one bolt. Over time, this fastening gives slackness, and the injectors begin to stagger in their sockets. After all, they are pressed from above by huge rocker arms driven by the camshaft.
The injectors are driven by powerful rockers
As this fault progresses, the injectors begin to break their seats in the cylinder head. In parallel, the seals are broken, and the fuel supplied and drained from the injectors (the supply channel is in the cylinder-head) begins to go either to the surface of the cylinder-head, and from there, through the oil channels flow into the oil pan. Or the fuel will leak into the cylinders.
In the wells of the injectors you can see the depletion on the circumference opposite the place of installation of the pressure bar.
By the way, the 1.2 TDI and 1.4 TDI engines never got pump injectors that are securely mounted with two bolts like the 2.0 TDI engines.
The 1.4 TDI engine fuel pump
The slide-type fuel pump delivers fuel to a distribution tube mounted in the cylinder-head. In the tube, the fuel supplied is mixed with fuel from the “return”. The fuel from the return is hot, it heats the supplied fuel so that all pump injectors receive the same mass of fuel.
The fuel pump, as on all injector pump engines, is one piece with the vacuum pump. It is driven from the camshaft. As it wears, fuel begins to leak into the vacuum part or simply runs down the cylinder block through a weak seal.
Another unreliable chain
In the sump is a module that combines a balancer shaft, oil pump, one intermediate sprocket and a hydraulic tensioner. This structure rotates at the speed of the crankshaft, driven from it by the chain. The chain is stretched over time by the very forces of inertia that the balancer fights against and that affect the crankshaft.
Not only the chain, but also the sprocket, which is pressed onto the crankshaft, cannot withstand the stresses. It can slip, damaging the crankshaft shank. In this case, the repair will be very expensive, and that is if you feel such a breakdown in time and immediately shut down the engine. Otherwise, if the sprocket breaks or the chain is destroyed, the oil pump stops working. And then the engine receives very serious damage.
There is an opinion that a strong negative impact on the life of the balancer drive is caused by urban driving with alternating cycles of acceleration and idling, as well as many people’s favorite “riding in tension”. In general, the 1.4 TDI engine is capable to pass more than 400 000 km. The 3-cylinder record holders in Germany have covered more than 700,000 km.