To all guys on here, have a question regarding a noise when running.
Am in the process of installing a '93 DOHC in a '74 F100, using as much MKVIII parts as possible (IFS, IRS, 4R70W).
Last November, was able to start the engine for the first time after (partially) rebuilding it.
Done on the engine:
- Heads removed
- Valves surface lapped
- New valve stem seals
- New lifters
- New chains and tensioners
- All new gaskets
- 5W30 synthetic oil
- Engine put together using assembly lube
- Oil pump packed for proper priming
- Engine had oil pressure almost immediately after starting
- New plugs Used Motorcraft or ACDelco on everything.
Haven't touch the short block itself. I drive the car up to Norway after i bought it (1200 Miles), no noises or smoke, engine was running fine. Only small rattling sound coming from the chain tensioners at start-up, that's now fixed btw.
- New flexplate
- New TC
- New TC nuts
- New filter & oil (Mercon V)
All electrical sensors new, no codes found when doing the KOEO tests. I have only run the engine briefly as the cooling system was not finished yet. Also only the cats installed, no exhaust system yet.... Haven't done the KOER tests, didn't want to run the engine too long.
I have just uploaded the video to YouTube: https://youtu.be/1gfSVhduZKg
In the video (45 seconds in), i rev up the engine a bit and when the revs drop there is a rattling / knocking sound? It disappears completely when at idle speed. Around 58 second i rev it up again slightly, same sound that disappears at idle.
Am currently offshore and reading every noise related thread on here to see what it could possibly be, now at page 137..... Still 120 pages to go....
Hope its something simple as a collapsed lifter... not a rod bearing or worse.... Was able to locate the sound, around cylinder 8 more near the bellhousing area. Have shortly listened to the head using a screwdriver near my ear, couldn't pinpoint it.
As soon as i get back in March i am going to do some more investigation but was hoping that one of you guys might be able to tell what it could be from experience.
Thanks in advance, Willem Holman