Tourney3p0

This is for a friend of mine.. the motor is a late 70's Corvette standard 350.

It's developed a dead miss in the last few days. The plugs, wires, and cap are less than two months old.

About the same time, we're starting to hear some clattering that I'm pretty sure is from a rocker arm. It's not just a faint clatter like bad gasoline either, it's pretty loud and annoying.

I'm almost certain the two are related. It'll always do it under a load but rarely does it at idle. That makes it difficult to figure out where it's coming from but I'm pretty sure this evening I can find it by pulling plug wires until I find the dead cylinder.

The first thing I thought was a dropped valve, but everything appeared to be okay when I removed the valve covers. I'm no expert but the pushrods and everything seemed to be functioning properly.

One thing I wasn't sure about was when I ran the car with the valve covers off, one rocker arm on each side shot oil about 3 feet whereas the others only barely trickled. Is this normal?

So to recap.. dead miss, clattering sound I'm almost sure are from rocker arms. No other unusual sounds.

It's hooked up to a TH350 so it doesn't really see high rpm's. Any ideas?

Fevre

Sounds like that lifter is collapsing, why the oil is shooting out, that will cause the valve not open, or at least not to open all the way. Try pulling plug wire for that cyl and see if the eng runs any diff.

Mr.Gearhead

I had the clatter and sputter above 3500- 4000 RPM. My lifter munched and the cam worn flat.

My engine "sounds" while driving.... Errrrrrr.... shift ERRRRRRRR shift VAREEEEERRRR pop pop spit spit crackle crackle... shift.... crap...

I tightened the rocker too much and caused my OWN carnage! The lifter became concave and the cam lobe looked more like a mini bearing journal!!!

:cry

Tourney3p0

This motor sounds the same throughout the entire rpm range. The clatter isn't really worse at high rpm's, but it's there regardless. It doesn't pop or sputter, just has a dead miss.

I think I'm going to run some seafoam through it this afternoon when we change the oil on the off chance that there's some carbon on the valves or something.

I'm probably going to be taking the rocker arm off this evening to check the pushrods (or will this be evident without doing so?). When I go to put the rocker arm back on and need to adjust the valves, do I simply turn the pushrod by hand until it's too tight to turn, then back off a bit? Or is there a better way of doing this with the motor running?

BB wowbagger

:lol: