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Terrible engine noises after replacing valve cover gasket

74Runneer

74Runneer

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My 318 was leaking a little from the valve cover so I decided to change it. I swapped it in and then started it up and it ran fine but starting spitting up even more oil than before. I'm sure the gasket wasn't on right so I took it off and then straightened it out. This time I bumped one of the pushrods and then it came loose so I took the rocker arm shaft off and put it back. Bolted over thing up and now when I start it it makes this awesome crack/ping noise and it barely runs. It sounds like the engine is destroying itself so I quickly shut it off. I took off the valve cover again and adjusted the rocker arm and push rods and tried it again and the same awful noise came back. Any idea why this could be? I didn't take any of the spark plug wires off so they are still in the correct order. Didn't touch the timing or anything. Could it be that the pushrods aren't on right?
 
Lemme get this straight; the engine was running perfect, but had a leaky valve cover gasket. You changed the gasket, but it leaked worse than before so you took the cover off again and slightly bumped a push rod and it became dislodged? Unless there is something broken or bent (prior to taking the valve cover off the first time), it would actually take quite a bit of force to dislodge a pushrod, so why do I have a feeling that there is more to the story?
 
That's correct. I dropped a valve cover bolt down in the head and had to take the rocker arm off in order to get it, that's when the pushrod popped off the rocker. Each push rod should be tight against the rocker correct?
 
74Runneer said:
That's correct. I dropped a valve cover bolt down in the head and had to take the rocker arm off in order to get it, that's when the pushrod popped off the rocker. Each push rod should be tight against the rocker correct?
Click to expand...


Yes, each pushrod should be in the socket of each rocker arm. But, all the valve cover bolts have to come off before the valve cover is removed, so there's no way that one should have been able to fall down into the camshaft valley.....unless they were carelessly placed where they could be knocked into the engine. Let that be a lesson.......and I'm not criticizing, just saying. That all being said, could anything else have fallen into the engine?
 
74Runneer said:
................ Each push rod should be tight against the rocker correct?
Click to expand...
I'm thinking not if it is the standard hydraulic valve train. They all need to be in the sockets correctly. The shaft needs to be torqued correctly (17-18ft. lbs?) Not all are going to be "tight" though.
I might pull them back out and roll them to check for any that may have bent.
 
The valve cover was off and I had one of the bolts in my hand and I dropped it down the head, I got it out with my magnetic stick. And no, nothing else fell in. I torqued the rocker arm to 200 in lbs like my manual said. Not all the rockers are tight against the pushrods, about half were. I think my next step is to unplug the coil and crank the engine to see if it's something mechanical or if it is something with the ignition. Is this a dumb idea?
 
Why would your ignition now be a problem?
What kind of valve covers are you using? Some aftermarket styles use screw-in baffle plates ... and I know from my profession that those screws are often only finger tight. It would truly suck if there's a tiny screw rattling around in there now. If you have MPs, Mickey Thompsons, Edelbrocks, etc., there should be three screws on each plate.
 
Hard to imagine its something electrical from post 1.
"...... it ran fine but starting spitting up even more oil than before............"
Are you rocker and rocker shafts on correctly?

shaft orient.jpg
 
There are a lot of wires/plug wires that could have been accidentally bumped. I guess I should take the valve cover off and just look with my magnet to make sure nothing else fell down there.
 
Yes, the rockers are on correctly and the pushrods seated in the little dents like they are supposed to.
 
I should note that when I started it, it would sputter and want to kill. It sort of sounded like it was a misfire/backfire, that is why I was thinking something non physical.
 
By the sounds of things, am I correctly guessing that you are a novice? You might want to start at the site of the initial problem; pull the valve cover back off, pull the coil wire and just crank the engine just to make sure all of the valves on that bank are acually opening and closing.
 
One or two pushrods mighta got bent.
It's a little tricky making sure all of them stay lined up as you tighten down the rocker shaft. I dunnit once on a 383 about 1979.
Straightened it out and no problems since.
 
When 74Runneer gets to the bottom of this, I'll tell you where I found the blue towel remnants after the valve guide seal job.
 
I just tried cranking it with the coil unplugged. All the valves move up and down but there is still some sort of grind noise.
 
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