I took the valve cover off my engine to try to figure out why I'm getting this rattling/knocking noise back by cylinder 8 on the top of the engine. I didn't see anything wrong in there so I left the cover off and started the engine to see if I could get a better idea what was going on. When I got back around front of the engine #2 exhaust was shooting a super soaker like stream of oil out over the and onto the fender. I've run engines without the valve cover before, but I've never seen anything like this. It makes a mess, but that's usually from the rocker arms splashing the oil around. None of the other rockers looked like they were getting much oil if any (probably the source of my noise).


My question is, would you suspect a bad lifter? Is there supposed to be some kind of flow restricter in them?


The engine is a 350 with vortec heads and roller cam in a 1988 TBI Camaro. (I built and tuned the engine, this is not one of those previous owner said ... situations.) The roller lifters, dogbones, and hold down were from the original engine and the cam is a Comp Cam.

 

Really? No one has ever seen this before? I'm going to replace the lifters. Does anyone think it could be anything else?

 

Huh. Never seen that before. Maybe a passage is blocked somewhere? Compare it to the other side and see if there's an obvious "OH, well that's my problem" thing going on.

 

Yeah, something's gone wrong with the "guts" of your lifter. They're supposed to meter a small amount of oil out the top to go up the pushrod and lubricate the rocker arm. That's obviously gone completely haywire in your motor, somehow and it's blasting an unrestricted stream of pressurized oil up there as fast as can make it up the pushrod.

Only the lifters restrict that flow of oil- the pushrod and oiling hole in the rocker arm are not a restriction to what should be a very modest flow of oil.

When you replace the lifter double check the pushrod and rocker arm for any damage. If the oil going into the lifter is all going up the pushrod that means there probably isn't much making it into the lifter's lower cavity, which is what keeps valve lash tight. So things have been slapping around on that valve for a while, as if you had the rocker arm backed off until it was clacking.

 

But where is the noise coming from? I never seen 2 p-rods have the same amount of oil coming out the rocker. I would take a automotive stethoscope and listen for the source of the noise. Also u can put a white mark on each p-rod to watch it and ensure it rotates. P-rod should rotate w/lifter or lifter & lobe is likely wiped. BTW u can buy little clips for your rocker arms that cover the p-rod hole and stop the oil splash.

Find the noise first.