Hello while pulling an empty 5x8 enclosed trailer today which weighs about 900lbs. with my 85 300SD the engine was working hard to keep up a 65-70 mph. As I was driving on my 75 miles home I did not hear any strange engine noise but when I stopped about 5 miles from home to look at something while the engine was was running I heard a weird noise. I'm thinking its a valve tick or maybe a broken valve spring. I will try to post the vidio I made of it and maybe someone can help me figure out what is causing this noise. I tried for an hr. to upload my vidio with sound in the end it would not post it as it said a security token was not met what in the world is that? I was able to post the vidio on You Tube cannot seem to tranfer it here.
https://youtu.be/6P0q0Gg6GpE I guess if you go to that link you can listen to the noise .