bigg_un

I have a 454 that I built for my '74...it is currently on a run stand..it has a knocking sound like a rocker hitting the valve cover between 1500 and 2000 rpm...removed the ds valve cover and started the engine...one rocker is pouring out oil..is this the sign of a bad lifter? I have never seen that much oil come out of one lifter..the engine runs great other than the knocking noise...runs cool and has about 25 lbs oil pressure at idle and 50 at 2k rpm...just trying to get an idea of where to start..

jackson

Check that one's pushrod tips and cup in rocker

bigg_un

Yes...they are in correct...I've set the lifters a couple times now...lifter is opening the valve...just spraying a lot of oil...

chevymans 77

lifters have an oil metering plate below the push rod cup, make sure its in there

Neal

jackson

Sorry, I meant their condition ... cracks, splits, fractures, etc. Perhaps you've already done so as you've re-set several times.

Neal has a good point.

bigg_un

Everything is brand new jackson...I guess I'm going to have to pull the intake to get down to that lifter and check it out...I'll probably just go a head and buy two more and replace it...don't know if that's problem or not but definitely easier to fix now before it's installed...

TimAT

while it's running, get it up to where the noise shows up and start pulling plug wires one at a time to see if it goes away or changes

HeadsU.P.

Pushrod squirts?
Some engine builders would say, that's wonderful. What's wrong with the other 15?

CanadaGrant

I think he means the oil is really shooting out, unlike the rest. I believe chevymans 77 is correct and there is an internal problem in one lifter that is allowing full oil flow and pressure without even pumping up the lifter. Metering disk or plate or something seized inside. My vote is faulty lifter.

chevymans 77

Oil enters the internal of the lifter and it needs the metering plate to control the amount of oil bled off to the rocker but still have enough of the pressurized oil to fill the space in the lower section of the lifter. The hole in the side of the lifter body used to fill the lifter with oil and the hole to the push rod without the metering disc are close to the same size, wont leave much oil to fill the lower section of the lifter.

the metering disc needs to be in there, don't know for sure this is the issue but if there is a noticeable difference in the amount of oil getting to this one rocker and this lifter is the one making noise then it would be the first place I would look.

Neal

CanadaGrant

Indiancreek

Have you determined the knock yet?

bigg_un

I can't say exactly where the knock is coming from but it sounds as though is in the area of the top of the motor closer to the front which led me to run the lifters again..while the cover was off I started the engine just insure I didn't have a flat lobe...this one rocker is pumping so much oil that it's going every where while the rest are pumping very little at an idle..I am going to pull off the intake and change it hopefully this weekend...I'll post back with the results...I was hoping someone else had run into a similar situation..

spinadog

I did. I had the exact same issue with #6 cylinder on my 454, spurting oil everywhere at idle (700rpm), compared to the rest. This was preceded by a ticking noise while warming up, that suddenly became a clacking noise when I pulled the plug. Lifters had 4600 miles on them from a complete engine rebuild. Bit the bullet, pulled the manifold and replaced all lifters to be sure. Make sure you follow the proper break-in process, same as if you replaced the cam and lifters (immediately at start, 2000rpm for 30 mins - make sure the tank is full and your car can cool when stationary). The lifter did not feel significantly different when I gave the 'push' test, but I agree, I think the metering was shot and therefore the lifter would not maintain pressure while running. 1000 miles later and all is good, about to get an oil diagnosis from Blackstone to ensure I am not grinding away my cam. Good luck!

bigg_un

Thanks spinadog...that's the type of info I was looking for...sounds like the exact problem I'm having...this tapping noise has continued to get louder... I'm planning on pulling the intake a replacing it...thank you for the reply...

Scottd

I had the EXACT thing happen to me a few years back after a major engine build. No matter what I did, the damn tick was still there. I even ground/cut some of the oil baffle out of the valve cover. I finally choked on my pride and took the car to the only speed shop in town. (I RARELY let other people work on my car.) It turns out.....I had a few loose valves. All that checking and re checking I did, and I was still adjusting them wrong. I felt like an *** because I honestly checked them a dozen times, I still dont know which ones I had loose.

Go back and recheck your pushrods. Ill bet you a happy meal thats your problem.