I've been working on getting my engine (603) running again and recently decided to purchase a used IP as mine wasn't pushing fuel out of one of the DV's.

About a week ago I was cranking the car over and everything sounded great, no unusual noises.

Then I got the new used IP and installed it and at the same time I remembered that I had not primed my new timing chain tensioner so I did that as well.

I also installed a new output shaft seal on the transmission but this noise isn't coming from that area and I can't see any way that it is connected.

So today I got everything back together and cranked it over and I hear a hollow metallic sort of scraping with maybe a slight clangning. The noise is completely inconsistent, sometimes it goes away completely, sometimes it gets to the point where I think I should stop cranking. But there doesn't seem to be any relation to where in the rotation of the engine the noise occurs.

It's definately coming from the engine but I can't tell where, I tried listening for it on a mechanics stethascope that was touching the timing cover. The funny thing was that the noise was not very pronounced with the stethascope in my ears, it was much easier to hear without it which makes me think perhaps it is not internal to the engine.

I pulled the valve cover and I don't see anything out of the ordinary nor can I hear the noise any better with the cover off.

I'm not even sure where to look next but I figure it must either be related to the chain tensioner or the vac pump or some combination of the two.

Any ideas?

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1987 300SDL 167k
1992 Volvo 740 140k
1990 Volvo 740 250k
1989 Volvo 240 269k

Anyone want to trade an old Volvo for an '87 300sdl?