I have a 70 Buick GS with a 455. The engine was making a ticking noise almost like an exhaust leak no exhaust leak found. Seem to run hot.now I have fluctuations in the oil pressure and a knock sound no longer a tick. Any suggestions on what this is? And or any suggestions on what to check on motor . thanks
Cut the filter apart and or pull the engine and inspect bearings. All you can do really. What is the hot oil psi? How much does it fluctuate? You can try an oil pump rebuild, but sounds likes that may be for not
your pressure is it like 75 when it starts and cold as it warms up at slowly drops to run 50 or lower. it's engine gets harder the knock becomes more noticeable not really noticeable when engine is cold and first start
Is the knock rhythmical, or does it come and go and vary? One thing you can look at is the torque converter to flex plate bolts. Also inspect the flex plate for cracks. Loose converter bolts and/or a cracked flex plate can make a knocking noise, and can tick when in gear. Your oil pressure sounds good. A bad rod bearing will make a rhythmical noise when that cylinder fires. Main bearings can make a dull kind of knock. Hopefully, it isn't a bearing problem.
Something that as you posted " started as a tick and is now a knock" would have me not running the motor any more and pulling the pan to look at Bearings!
I third that. Don't risk blowing the engine if it's a bearing. It might be a good idea to do some tlc on it while your inspecting the bearings.
Two things that have gotten me in the past when I thought motor was hurt.....loose windage tray and loose flexplate. Both sound similar to rod knock.
I've been burnt by a loose or cracked pulley aswell. i always run it with out the belts as a first step. unless the oil pressure tanks
