Here is the way I cleaned mine on my 216. First I removed the attachment bolt on the pan. It had a strap that is secured with a pan bolt. Then I wiggled it free of the block. Next i took a screw driver and hammer and removed the top cap. At this point there was no visible passage between the tube from the block and the road portion. I put the assembly into a degreaser solution and several hours later it was clean. As it turned out there was a baffle inside with holes!