617 engine knock/ hard start
 

I traded a kayak for a 82 300sd 140k that had not been running for at least 2 years. After rebuilding the injectors changing plugs other routine maintenance I am able to start it after multiple tries. here is the link to a video of it running. 82 300sd hard to start then knocking.. any ideas? - YouTube

Sounds like a spun rod bearing. Time for another engine.

First things first: adjust the valves! If that doesn't cure the problem, well, it's something serious.

Questions:

How long had it been running when you did the video?

Did you use any starting *aid* to get it going (such as ether)?

Does the knock/rattle match changes in RPMs, both in frequency and volume?

Can you please do another video, which includes:

1. Steady camera shots, don't move around the whole time
2. At least one closer shot of where you can hear the noise the loudest
3. No background talking
4. LIGHT (I know you are concerned with the sound, but it helps to be able to SEE what is going on too)....

Thanks for the response. I am going to go further look at it today. When I had first got the car running it didnt make a knock. That was a month or so ago.It ran for awhile when i first got her going. But due to some other things that still needed sorting it wasnt driven.. The car hasnt been out of park. Just a couple engine revs. I got it going again it last night and the knock started. The knock is at a higher frequency when I give it some juice. I used wd40 in the intake.. I am going to try and check the injectors when I get to it later today and I will try and make another vid..

Are you sure it is a "knock" that you are hearing and not "nailing" (precumbustion)??

What's the oil pressure like? What's the oil level like? Use a stethoscope to try to narrow it down. It does sound like a rod but I wouldn't jump to that conclusion yet.

Listen to the video again. The knock has two elements to it. If it were a bad injector, it would only have one. The second sound could be the piston hitting the head at the end of the exhaust stroke.

When did you use the WD-40? Please read this post by Ozarkdude before using starting fluids...

Wow is there oil in the engine? All that smoke out the rear probably goes with the knock.....to loud for an injector nail....Could be the vacuum pump came apart....

That nearly rings like a bell.

You should be able to work out from where that racket is coming from - it is pretty difficult for us here to do that via the interweb...

The flex on the downpipe was rusted I had another flex welded on and will be getting around to welding it together soon.

I had a mechanic looking at it a while back and he had used harsher chemicals on it and when he started it awhile ago many it is possible that the engine now is running backwards? The intake seems to push out a bit of smoke... If thats the case would you think it possible to fix with out pulling the engine. Its sounding grimm. I have someone that primarily works on old diesel 300s coming by in the next day or so. So I should know soon what is going on. I also noticed that the oil pan is not the original pan. Maybe something was seriously wrong before I got it, who knows. I felt a $400 kayak was a great trade. I still think it to be, the body minus the not so appealing look of whats going on with the clear coat has great barely worn interior, flawless wood trim, windows/electric all working engine read 140k adjusted valves everything in there looked really clean.