Post by Volktales on Aug 31, 2017 20:16:51 GMT -8
Sooo, as we all know, new design is good, high tech is great, the next is always the best. Sure... When it comes to engine technology, this is not always the case as VW has so brilliantly proven with their TSFI series of engines (also known as TSI). This family of engines are commonly 2.0 L four cylinders that feature turbocharged stratified injection. This is commonly known as direct injection in that the fuel injectors spray directly into the cylinders instead of the intake manifold like all previous injection systems. These engines also feature common modern ideas such as tuned intake manifolds with flap valves, variable camshaft timing, and variable valve lift on some models. Also like most modern engines, timing belts are a thing of the past, and chains have taken their place. The TSFI takes this further with dual chain driven balance shafts, and unusually the oil pump as well. The following short video gives you a good idea of what goes on inside this engine...
The advantages of this high tech engine are the usual better efficiency, power, and tighter emissions standards. Too bad the disadvantages far out way any of these!!! High tech generally leads to a greater complexity and the TSFI is no exception. Unfortunately VW tried too many "new" features in one powerplant and the result has been extremely poor reliability in this case. There are FIVE main issues these engines suffer from that are all too common. Later I will link a video in which a mechanic spells it out what these problems mean to the customer, but here is a quick rundown...
1. Intake manifold issues. Most modern engines feature plastic manifolds for weight savings, and these manifolds have built in flaps that change airflow characteristics depending on RPM and load. The actuators for these flaps and sensors have not proven reliable and generally complete manifold replacement is the only option.
2. Intake valve deposits. Direct Injection might be good for efficiency, but it has a MAJOR downside. In older designs, when the injector sprays fuel into the intake manifold, it somewhat "washes" the back of the intake valve and helps keep them clean from carbon buildup. Direct injection sprays into the combustion chamber itself, so the valves do not receive any cleaning effect and plug up with carbon alarmingly quickly. This is not just a VW problem, as other manufactures are experiencing this issue as well.
3. Water pump failure. Something our vintage VWs never needed. Traditionally water pumps were connected to the crankshaft via a drive belt, although when timing belts became commonplace, many manufacturers chose to drive the water pump directly from the timing belt. The generation before the TSFI series were of this design...
Continued...
The advantages of this high tech engine are the usual better efficiency, power, and tighter emissions standards. Too bad the disadvantages far out way any of these!!! High tech generally leads to a greater complexity and the TSFI is no exception. Unfortunately VW tried too many "new" features in one powerplant and the result has been extremely poor reliability in this case. There are FIVE main issues these engines suffer from that are all too common. Later I will link a video in which a mechanic spells it out what these problems mean to the customer, but here is a quick rundown...
1. Intake manifold issues. Most modern engines feature plastic manifolds for weight savings, and these manifolds have built in flaps that change airflow characteristics depending on RPM and load. The actuators for these flaps and sensors have not proven reliable and generally complete manifold replacement is the only option.
2. Intake valve deposits. Direct Injection might be good for efficiency, but it has a MAJOR downside. In older designs, when the injector sprays fuel into the intake manifold, it somewhat "washes" the back of the intake valve and helps keep them clean from carbon buildup. Direct injection sprays into the combustion chamber itself, so the valves do not receive any cleaning effect and plug up with carbon alarmingly quickly. This is not just a VW problem, as other manufactures are experiencing this issue as well.
3. Water pump failure. Something our vintage VWs never needed. Traditionally water pumps were connected to the crankshaft via a drive belt, although when timing belts became commonplace, many manufacturers chose to drive the water pump directly from the timing belt. The generation before the TSFI series were of this design...
Continued...
