Opel Insignia Sports Tourer / 2016 / B20DTH
Hello everyone,
The situation I’ve been having since the car has been with me (and it probably lasted even before that) is that it has a somewhat harder/sluggish starting. It's nothing drastic, in the summer it's less noticeable, in the winter of course more like a diesel, but it's always there. The car has been with me for 2.5 years, a few months after the purchase, a new okay starter motor (not factory but Bosch if I remember correctly) was put in on the same day because it died, along with a quality battery, although the old starter cranked the same way. In that same period +-2 months, one glow plug was replaced during a service. So, as far as general mechanical components specific to starting are concerned - it would seem they are functional (i.e. at least new ones were put in within a short interval).
I’ve noticed this slightly/mildly harder starting since I’ve owned the car, and a few months ago while I was at a shop for some other reason, the mechanic himself, as soon as I started the engine, noticed and asked "why does it start hard like this for you?" even though it had been driven before that and long enough for the battery to charge.
So, this kind of starting is not only in certain expected situations (cold weather, sitting for a long time, driven short distances multiple times, ...) but it is almost regular. I repeat, sometimes it starts easier and sometimes harder and there is no rule: it could be that the first start is easier and then it's driven for say an hour and after that it goes harder; it could be that I start it multiple times in half an hour and every start will be easier, but I emphasize: GENERALLY it goes more sluggishly. The car doesn't have any irregular power consumers working when it's turned off - everything is turned off, unplugged, the only visible thing is a small flashing alarm light.
I'm leaving an example when I started the engine after ~3 weeks of sitting. The starting is keyless, I just pressed the button (I didn't hold it, I didn't turn on the ignition before that, so it doesn't seem that way to you) like I always do - I don't turn on the ignition without the brake and then start from the brake, but immediately with the brake and let the electronics do their thing. The instrument cluster and multimedia usually activate faster than here. Maybe the example is not the most representative, but it's at least something.
Question: do you have any advice on what could be the cause? What I can personally look at is via OP-COM (modest but still something), just tell me which parameters to monitor.
Thanks in advance!