Continuing on what I wrote few days ago, here is part 2 of the Opel/Vauxhall Vectra C 1.9 CDTI (Z19DTH) engine overview. Some of the most common things were already pointed out, in this article I’ll add a few more.
For starters, the glow plugs:
Be carefull if you’re thinking of replacing them, they can snap quite easily. It’s good to already add some lubricant few days before you’re going to remove them. The biggest part of the glow plug is however hidden inside the engine and is not visable on the pictures above. In total, they look like this:
Commen Rail schematics:
In the following video there is a good explanation about the common rail system in modern diesel engines:
In this video they also mention the swirl flaps. These flaps are located inside the intake manifold, but can sometimes be a source of error. Since using the EGR system involves reusing exhaust gas, the EGR valve and intake manifold’s swirl flaps might block or get damaged because of dust particles that stick around. A good tip is to check the EGR valve once in a time and clean it (does not take a lot of time since it is easily reachable). Alternatives is to block of the EGR valve so that no exhaust gasses are used anymore. On the internet you’ll probable find some blanking plates, but you can also make one yourself:
The boost sensor, also known as MAP (manifold absolute pressure) sensor, measures the air mass flow rate. The ECU can then take the exact fuel amount to make a optimum combustion.
On the front of the car there is also the MAF sensor, located just next to the intake air filtering box:
The MAF (mass airflow) sensor senses the mass airflow of air being brought to the turbo. It may also be a source of problematic engine behavior, although it occurs less than malfunctioning EGR valves for example.