Steam convector element clicking when heating comes on

Hello guys,

Two years ago, I asked the Wall community regarding banging/clicking noises my circa 1930's Arco steam convectors were doing. I received a lot of valuable advices, and thank you all for them. I adjusted 2 convectors in living room, and no more major issues so far (fingers crossed). But as for my bedroom, I decided to replace very big convector with more compact modern steel convector. When heating season started, I was very disappointed that the clicking noise I was upset about was still there…I had to wait till the next summer to disconnect the radiator valve and inspect the supply pipe. So, when the season was over, I disconnected the convector and steam valve and didn't see any obstacles but noticed that the pipe itself was slightly inclined to the right. I could move the pipe several inches to the right-left and up-down, but incline was always the same. Because of that incline the elbow between the valve and convector was inclined as well and I suspected it may be one more possible noise source; so, when connecting the valve back, I decided to reverse it to the left (See attached picture). Incline in still there, but I am sure there is no water hummer in the elbow. I understand that due to the valve alignment the connector pitch is extreme, but in all less extreme scenarios (I tried all possible combinations) the result is a leak. I tried several air vents and sizes from 4,5 to C and D, but the noise was still there. It can be more intense at night, when the system cools down and the cycle starts. When the valve is closed, I can feel slight vibration when the cycle starts. What I did wrong and what can be done to minimize the noise? Thank you in advance!