My car underwent a cylinder test for compression. They then told me that the 4th cylinder is not getting fed any compression. It could either be worn out piston rings or something broken at the valves. Are there any other causes to this problem because now the Hyundai dealership said that they gonna take more than 5 days due to the time it will take at the engineering shop too. What makes this a complex procedure?. I am considering taking it to a reputable mechanic as I think it will work out cheaper in half the time. What are your thoughts or opinions on this matter

Regards

Parwez