My SD started making a funny knocking sound yesterday. It reminds me of loose valves a little but not quite. Also it is loud enough that I didn't want to just keep driving it. It is kind of like a double tap one louder than the other once or so a revolution.

So I pulled off the VC checked all the valves and all are good. I also thought it might be the chain stating to come apart but it looks fine also. With the cam marks lined up it reads ~3.5deg. at the crank.

However I got it to recreate the sound while manually turning it over. It is coming from the area of the vaccume pump and IP.

As I slowly rotate the motor it makes a creaking(something being conmpressed?) sound for about 20 degreees of rotation and then a light knock followed by a louder knock within another 5 degrees of rotation. It seemed to do it at least 2X per revolution.

I'm a little worried and wont drive it until I have it fixed.

Any help will be greatly appreciated!

Thanks,
Stephen

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85 300D 305K miles WVO(105K so far), Mine
82 300SD 235K miles BIO-D, Wifes
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