[Solved] Opel Astra G 2.0 16V Engine Issues: Poor Acceleration, Low Rev & Oil Leak - Coil Replacement?

Hello. While driving the Opel Astra g 2.0 16v, the engine started to run like a tractor, it accelerates poorly and does not rev. The problem seems to be easy to solve because I immediately thought that the spark plugs, cables and coil needed to be replaced. I only replaced the spark plugs and cables, the problem still remained. I thought maybe there was something wrong with the engine, so I unscrewed the oil cap and saw the oil pouring out of the head. So my question is whether to go further into the costs and buy this coil, because if only one of the cylinders wasn't working, the oil wouldn't jump out of the head like that. And if it's something with the bearing, then due to the low value of the car, it's not worth repairing the engine... And one more question: is it possible to check somehow whether the coil is working properly, e.g. with a voltmeter? Please help. Below is a photo of the coil for my Astra.

As one user says in his signature, "There may be many reasons."
Buy a used coil and you can replace it.
Usually, in the 2.0 16V there are two sensors - the crankshaft and the camshaft.
When analyzing your problem, you can try to measure the compression, which will tell you a lot about your condition and give you further tips.

For this Astra there is only a camshaft sensor, I cannot find the crankshaft sensor anywhere.

Oil splashing is normal in this engine.

Check which cylinder is not working. Then check if there is spark and everything will be clear.

Before replacing the cables with new candles, there was no spark on the fourth candle. Unfortunately, I didn't have time to check the spark with the new cables. The coil will definitely need to be replaced, but I am looking for a way to check whether the coil is working properly.

However, the reason was the coil. I replaced it and the problem disappeared. I'm closing the topic.