Hello kinda new here, I have a 1994 dodge ram 1500 2x4 318 auto, and it will some times have a quite knock coming from the manifold. When its not doing that it looses oil pressure when not on the gas, it runs about 40psi regularly and drops to about 35 psi. I don't know if that's good or not and the temp doesn't rise above 160. I am mainly concerned about the knock and the oil pressure. the truck has plenty of power and doesn't smoke. any advice will be appreciated. thanks

 

Plenum gasket....or cracked head, thats whats comming to mind...

 

when the last time a tune up was done, these trucks are really picky about plugs!

alzso look down your throttle body for oil for a plenum leak, if its leaking there should be a noticeble amount of oil down there.

 

I will look in to that thanks. I will let you know if I find anything

 

Is this knock when you are on the throttle as in pinging under load or is it knocking when it just idles?

 

well when it does knock it does all day and usually wont go away, but the knock is there under a load or at an idol, but its not a ping. it sounds like a bad bicycle bearing if that helps. I also looked in the throttle body down in to the pendulum and it is black but no oil that i can see.

 

Normally if you have bad bearings or oil pump the oil pressure will drop to zero at idle after the motor is warmed up. You need to verify the oil pressure is true by getting an aftermarket unit. If it is ok then you should check out all the pulleys on the front of the motor and make sure it's not coming from one of the various accessories. Remove the belt and check all the pulleys.