#8 cylinder noise

[Dennis Wilkie]

I've been trying to figure out what this tapping noise is for awhile now. I finally pulled the plug wire off of the distributor, and it was the very 1st plug I pulled that made it stop. So, #8 was tapping, so I readjusted the valve, and it got quiet...for a couple of minutes. It just came back and the valve acted like it wasn't fully opening or closing, and i've been fighting a low oil pressure issue forever now. The video I attached is after I readjusted the rocker arm (before I snapped the valve cover bolt in the head). Is this going to be a failed lifter making the noise? Also, is that part of the reason my oil pressure keeps tanking so fast, even after replacing the oil pump?

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[stutaeng]

I didn't know an engine could be run without valve covers...but just a novice here.

Sorry, I can't comment on the noise issue.

But on the oil pressure problem, changing the oil pump won't solve that. The oil pump only supplies the flow of the fluid (oil.) The pressure is created by the bearing clearances.

Have you checked pressure with a mechanical guage? The instrument cluster gauge is not a direct pressure measurement, more like a "high" and
"low" reading.

 

[91c1500sleeper]

Sounds more like a screaching sound. Yes you can run an engine without the valve covers. Those clips over the pushrods help keep the oil from spitting out at you. Low oil pressure is from bearing clearances too much, the drive rod for the oil pump not long enough or engaged properly with the dizzy. What motor are you talking about, mileage, did this issue just start or has it been there for a while?

 

[Dennis Wilkie]

The pressure has been getting progressively worse. But i've got an aftermarket gauge and the top of the motor has around 10k miles on it. I swapped the oil pump and it doubled the pressure to around 40-45 psi cold when it was only getting up to around 20 at best. The motor itself came out of an '87 Corvette, 5.7L. I had the pan off a couple of weeks ago and other than a broken piston skirt, nothing seemed out of the ordinary. Nothing moving around any more than usual, and it doesn't sound like a spun bearing. My cylinder compression numbers are all between 165 to 190. The attachment is from a cold start before I put the new oil pump in. I had to get rid of the always leaking factory sending unit

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[smdk2500]

I didn't know an engine could be run without valve covers...but just a novice here.

.

off the topic of this thread you can run a 6.5 and 6.2 with out the intake manifold.

 

[Donald Mitchell]

off the topic of this thread you can run a 6.5 and 6.2 with out the intake manifold.

They have to adjust the rocker arms somehow. So yes.

 

[smdk2500]

They have to adjust the rocker arms somehow. So yes.

umm how do you adjust rocker arms though the intake valley?

 

[489burb]

push rod looks like its moving back and forth like its bent, i'd pull the intake manifold, lifter or push rod is easy, hopefully cam is ok

 

[Dennis Wilkie]

push rod looks like its moving back and forth like its bent, i'd pull the intake manifold, lifter or push rod is easy, hopefully cam is ok

Yeah, it's easy enough, but having to take that intake off for the 3rd time in 2 months is starting to get expensive. All of these gaskets are really starting to add up, especially since I refuse to buy the cheap ones.