Franswa

Do any early 455s require valve adjustments?

svnt442

No.

RROLDSX

No but you may have an issue with pushrod lengths if your heads have been planed or your head gasket thickness has changed. Why do you feel your valves need adjusting?

joe_padavano

No Oldsmobile engine since the 1957-58 J2 came with adjustable rockers. If your 455 has a stock valvetrain, there is no ability to adjust.

Franswa

well I have a knock that sounds like in a head not in block...not a hydraulic sound like a rod or piston...what are some preliminary checks I can make if any once I remove valve cover..btw drivers side

oldcutlass

The only thing I can suggest is remove the valve covers and inspect the rockers, bridges, and springs. Make sure there is preload on all the valves when they are closed. Any loose rockers at that point need to be checked for wear. If you don't see any substantial wear then you need to pull the intake and inspect the bottoms of the lifters and cam lobes.

How is your oil pressure when warmed up?

Franswa

30-35 psi warm...if in fact it’s coming from below what would I look at?..will removing the oil pan reveal anything and I did pull plug wires one at a time with it running but noise remained

oldcutlass

You said you think its coming from up top, look at the valve train first. Top end noises sound like tapping, bottom sounds like a heavy knock.

Franswa

sounds like a soft thump that’s, “thump, thump,thump with rotation”

Franswa

btw anybody..is there a more reliable manual with more detailed info than a chiltons repair manual?

Sugar Bear

Check that the torque converter bolts are tight.

Franswa

update: eliminated top end possibles and now on bottom...removed pan but no metal flakes or pieces just dirty oil after a change but previous owner said it sat for 7 yrs......nothing hanging down or obvious..so should I be checking mains next and if so what am I looking for or trying to determine?