I have an Opel Signum 2.2 DTI and I have some problems with the cold start (in fact semi-cold) since the autumn.
In the morning if the temperature's enough low glow plugs on and there are no problems with the start. After that if I leave the car for some hours, by the next start the glow plugs do not come on it's really difficult to start the engine. The car just crank and crank for 10 to 20-30sec. then finally starts with a big cloud of smoke. The same sh*t happens if on the morniing the temperature is not enough low for glow plugs to come on. I have read a lot about this problem, but didn't see any solutions yet. Opel dealers just say "You have to change the pump" and the case is closed for them.
Is there a way to make myself any manual pre-heating by a switch or maybe by a relay without damaging anything? It seems that if glow plugs on, the car starts extremely easy, so I'm thinking in this direction.
Are all that problems a matter of changing glowplugs, glowplugs relay, temp sensor, leakoff pipes, injector seals or it's caused by an engine wear?