[ilhanozgor]

Hello, there was an oil leak in the transmission oil cooler of my 2011, 184hp, 320d vehicle. I went to the mechanic and he changed the gaskets of the oil cooler and in addition the o-rings of the hoses coming and going from the transmission. I traveled about 20 km. I stopped it and started it about 3 hours later. I went 100 meters and stopped at a red light. While I was waiting with my foot on the brake (gear in "d" position), my car started making severe knocks every 6 seconds while it was stopped. It looks like someone is pushing you from behind. There is no problem when in reverse gear, and there is no idle fluctuation, it just knocks when stopped. I went back to the mechanic and he added 1.5 liters of oil to the transmission. Then he reset the transmission and made adaptation, but my problem was not solved again. (It only happens when the engine is cold, it doesn't knock when it warms up)