head/lifter noise

[batch]

after the truck is warmed up i start getting a nock,it varies on when it starts and is not consistent at all. oil pressure is okay. 30 psi while cruising and 15 while idling after is warm. i pulled the valve covers off and one head is not getting as much oil as the other side. what could be the cause i dont know how many mile are on the motor for sure so i guess it could be the bearings but what about lifters?

 

[Chevy305]

just sounds like a well worn small block to me...

 

[GMC1977]

a bad oil pump or clogged up screen maybe??? toyotas had a problem with the oil screen clogging up and causing oil pressure loss...

 

[chulisohombre]

bad lifter or rockers that need adjusting will cause a tic not a knock.whereas a knock would be a rod bearing getting worn if i could guess.not much oil will cause that side lifters not to pump up and would also tap but not knock like you are saying.is it a tap or more of a knock.bad fuel would make it have a knock because it wouldnt be burning the fuel correctly.incorrect timing off by a few degrees will knock a lil also.easy things first checked.

 

[diesel4me]

I have read some small blocks can suffer from oil starvation on one bank only,if the distributor isn't installed in the proper position..in actual experience,I haven't seen it happen myself though..since the lifters get the oil first,and its delivered to the valve rockers via the pushrods,if they were clogged or the pushrods were blocked up,less oil will get "upstairs" on that side..a worn bearing could be reducing the pressure delivered to that side of the engine too..usually the heads and valley area under the intake sludge up a lot worse than the lower end,you'd see a ton of sludge under the rockers if the oil pump screen was clogged most likely--and both sides wouldn't get much oil,not just one..