I have a buick 455 in my 59 f100 with the most aggervating Nock/tap problem. Engine runs like a champ and has great oil pressure but here's the problem after it gets to running temp, if I turn it off and let sit for 20 min the knock/tap noise starts on initial start up but only lasts 20 sec at most. And thats even if it does make that sound. 50% of the time its quite.!! not sure if its a lifter losing prime or getting stuck or worse a main bearing. Any suggestions would be helpful. Thanks. Posted using the Full Custom H.A.M.B. App!
Here is my engine info 1973 Buick 455 Oem cam and valve train Running temp 180 deg Oil pressure. Start 70 psi Running temp 15 psi at idle Thanks agian. Posted using the Full Custom H.A.M.B. App!
I've been wrong before but i would say its a lifter. I would think that if it was a bearing it would be bad and stay bad so you would have the noise all the time and i would think see an oil pressure issue. Posted using the Full Custom H.A.M.B. App!
Yeah thats what im thinking. .. its always gone with in 20 sec. You can almost count it out. Lol Posted using the Full Custom H.A.M.B. App!
It does sound like a general high-mileage wear issue. I've had similar situations where I went to a 20W50 oil and it got a lot better. In worse cases, I'd run a straight 50 weight oil. Bob
I've done a lot of research on this engine. And 10psi of oil pressure at idle is normal. (1000rpm) Not sure why. Maybe its the low oil capacity. Only 5 qts for a 7.5 ltr motor. . Posted using the Full Custom H.A.M.B. App!
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