Engine rattle help.

[Gaugster]

Hi - Got this Cougar about 1 year ago. Mechanically it was neglected by the previous owner for the most part. There is a periodic rattle I discovered recently. Can anyone pinpoint what is the most likely culprit? In the video the new rattle or tick in most easy to hear at about the 10 second mark.  Afterwards some wind noise starts to drown it out. Can be heard from the front but most noticeable on the drivers side. I put a long screwdriver to my ear and probed the valve cover, distributor, intake and timing cover but couldn't isolate it. The engine is very cold blooded and the compression is down. I should note that the compression that that I did was with the engine ice cold.  I know that's not technically correct but I wanted the data for future reference. I don't have any documentation on this engine. As my handwriting is terrible - The number in ( ) next to the PSI is the number of compression strokes needed to get to a maximum. I was told i was a .030" or .040" over rebuild with an RV cam. It has a Performer RPM intake. The PO was using 10W-40 Castrol conventional oil. The zinc was 800ppm. Not super low but not exactly enough for the flat tappet lifters that I suspect are inside. I use the same type of oil but add a ZDDP additive. When I did the first oil & filter change I opened up the filter. I could see obvious signed of metal flakes.  A few flakes were the size of coarse sand. I didn't take pictures but did have the oil analyzed. The age of that oil was unknown.

 https://www.youtube.com/watch?v=ErGQttb3wz0

[WConley]

That doesn't sound internal to me.  It's more like something hanging loose, or maybe a bearing on a front end accessory.

Have you grabbed the fan and pulled on it to check the water pump bearing?  Is there a heat shield somewhere that's loose?  It could even be the PCV baffle under a valve cover.  The sound seems irregular - coming and going.

[GerryP]

Take off all of the drive belts and see if that makes a difference.  I agree with Bill.  The sound isn't an order that you would get from a piston pin, engine bearing, or valvetrain. 

[Gaugster]

Well I hope you guys are right as that would be good news. I'd like to keep this engine running as long as possible until I get a more stout replacement prepared. Thanks for the belt removal suggestion.

[Falcon67]

X4.75, sounds like rotating mechanical noise from AC, AC clutch, PS pump, possibly idler pulley bearing.  Pulling belts excellent idea. 

[shady]

fuel pump. arm return spring breaks or falls out giving the arm lash.