hotrod351

well my old 70 mustang hasnt been started for months. started it up and heard a awful knocking, and i mean a knocking. sounded like it was coming from the center of the engine. turned it off and checked the oil. oil full, oil pressure on the gauge showed high. started it again, same problem, turned it off. let it set for a few minutes than again, still knocking then all the sudden it stopped. ive had a couple of knocking rods in my days but as i remember they dont go away. and no it wasnt a rocker arm although it just might of been the sound of a lifter hitting the cam but again i couldnt hear anything on the top, i listened to each valve cover and it was silent. guess if was a rod it will do it again. anything else to check for.

kenash

Hi,
Have you tried manually rotating the engine? From your description, doesn't sound good!
Good Luck!

hotrod351

it stopped and sounds perfect. yeah sounded really bad. well guess if there is damage then its already done. ill be tarting it again today. if it does it again then ill order a new engine.think there only 2 or 3 thousand for one with a warranty. then it will have a new engine. not sure of the actual miles on it when i bought it but my wifes has put at least 80 or 90 thousand on it, still doesnt use and oil.

fastbackford351

My last 351w started doing that after I kissed the high side of 7.5k rpm and scored the hell out of a couple of my cylinder walls. The knocking sounded like hell but then would subside just a little. Still ran like a raped ape but I couldn't stand the sound.

I dropped the pan, pulled the heads and slugs then rehoned the cylinders with my trusty cylinder hone brush and Ryobi drill. No more knock and lessons were learned.

hotrod351

well have started it four times since and no sound, quite and smooth.

Gun Jam

maybe it took that long for the oil to prime up and flow to all the moving parts. Once it got there problem solved....

-Gun

hotrod351

i dont know. couldnt figure how id get a knocking rod from just sitting for 3 months. i dont drive it any more but didnt want to have to buy a new motor for it.