Push rods coming loose

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trapster

trapster

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63 Dart original engine

So I went to start the dart and the battery was dead. I left the lights on.:banghead:
I charged the battery.

The car started but sounded rough and there was a lot of valve train noise and it was missing. It sounded fine and quiet the day before.

I pulled the valve cover and the number 6 exhaust push rod was no longer touching the rocker arm. It wasn't bent or damaged in any way and the rocker was not out of adjustment it was just off. So I re-installed the push rod and readjusted the all of the rockers.
I let the car idle until the car was up to temp and then set the intake to 10 thousandths and the exhaust to 20 while the engine was idling.

it sounded great, I shut the engine off.

5 hours later I went to start the car and it was missing again. I pulled the valve cover and now the number 4 exhaust push rod was disconnected. I repeated the procedure above and then immediately drove the car, it is fine now but I haven't let it cool down to try it again.

So WTH :banghead:

I checked the timing with a light and it is fine.
 
i think your cam is eating its self... or make sure your shaft hold down bolts are loosening... 30 ft lbs tq for those
 
Or your valves are sticking open and it just fell out. I would push down on the top of each valve by hand to see if any have a excessive amount of reistance to movement. You will have to rotate the engine to get every valve shut to test them.
 
mcnoople said:
Or your valves are sticking open and it just fell out. I would push down on the top of each valve by hand to see if any have a excessive amount of reistance to movement. You will have to rotate the engine to get every valve shut to test them.
Click to expand...

good point... the guides could be sticking...
 
I was thinking that too.
Would it be worth trying some moly additive?
 
805moparkid said:
if its eating its self its over with... same with the guides...
Click to expand...

I was thinking of sticky guides when I posted that.
Maybe it has an older style (Needs Lead) guides?
I can't imagine a cam being that worn down and not running like crap.
 
if its running fine till it cools off i dont think it would be guides, because they should stick all the time or atleast when starting up maybe? i would think lifters bleeding off maybe. or cam going south like said above.
 
dustinmoran91 said:
if its running fine till it cools off i dont think it would be guides, because they should stick all the time or atleast when starting up maybe? i would think lifters bleeding off maybe. or cam going south like said above.
Click to expand...

Think about this though.
Even if the cam was totally rounded off the pushrods still wouldn't fall out.
 
TrailBeast said:
Think about this though.
Even if the cam was totally rounded off the pushrods still wouldn't fall out.
Click to expand...

thats why i was thinking about the lifters bleeding off first becuase the cam would have to go completly round and then shave some more to get enough room to let a pushrod out and since it runs good after adjusting them out i would think the lifters are pumping up and then when cooling off they bleed pressure and slack down enough to let them out
 
I am thinking the sticking valve when cold is most likely the culprit.

I think a dose of Marvel mystery oil is in line.
Or maybe a quart of synthetic oil.

The car runs fine but it is smoking a little more now than before.

Thanks for your help.

David
 
trapster said:
I am thinking the sticking valve when cold is most likely the culprit.

I think a dose of Marvel mystery oil is in line.
Or maybe a quart of synthetic oil.

The car runs fine but it is smoking a little more now than before.

Thanks for your help.

David
Click to expand...

Yep.
Even if the lifters did bleed down, they are still spring loaded and wouldn't let the pushrods come out.

This can only be two possibilities.
1. the rocker shaft bolts are backing out. (this would be really obvious)
2. the lifter is returning to the down position faster than the valves are returning to closed position. (allowing a big enough gap for the rod to jump out)

Mystery oil might do it, or a good dose of lead additive in the engine oil.
Either one will require you run it for awhile before any change would be noticed.
I have heard that Seafoam is pretty good stuff but have never tried it myself.
 
dustinmoran91 said:
does it have solid lifters? that wasnt mentioned above so i didnt know
Click to expand...

Sorry I didn't mention this, but in my defense I did mention it was an original engine, and I did talk about adjusting the rockers.

Mia Copa and thanks for your input.

:)
 
guides will stick when hot due to tolerances getting tighter... so its a possibility...

when a cam goes it literally eats the cam... so it you set it at .010 or .020 thou, if the lobe tip goes away that clearance will increase greatly...

solid cam so bleed off isn't an issue...
 
dustinmoran91 said:
I had no idea that slants had solid lifters.
Click to expand...

a lot of people dont, let alone realize they need the occasional lash adjustment. they automatically assume their slight miss is fuel/ignition and ticking is low oil pressure or bad lifters. i have always set the lash before doing anything else.
 
trapster said:
63 Dart original engine

So I went to start the dart and the battery was dead. I left the lights on.:banghead:
I charged the battery.

The car started but sounded rough and there was a lot of valve train noise and it was missing. It sounded fine and quiet the day before.

I pulled the valve cover and the number 6 exhaust push rod was no longer touching the rocker arm. It wasn't bent or damaged in any way and the rocker was not out of adjustment it was just off. So I re-installed the push rod and readjusted the all of the rockers.
I let the car idle until the car was up to temp and then set the intake to 10 thousandths and the exhaust to 20 while the engine was idling.

it sounded great, I shut the engine off.

5 hours later I went to start the car and it was missing again. I pulled the valve cover and now the number 4 exhaust push rod was disconnected. I repeated the procedure above and then immediately drove the car, it is fine now but I haven't let it cool down to try it again.

So WTH :banghead:

I checked the timing with a light and it is fine.
Click to expand...
you set the lash with it running????????????
 
73AbodEE said:
i have always set the lash on my /6 with it running
Click to expand...


All slant six engines had solid lifters until the 1981's came out. Ma Mopar changed them to hydraulics as a nod to the exhaust emissions druids at the epa.

I guess the millions of slant sixes with mal-adjusted clearances on their solid lifter cams probably have a dirty exhaust signature on a meter...

Ma Mopar continued to make that engine with hydaulics until 1983 in cars, '87 in trucks and '87, as a marine engine.
 
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