ticking not fixed by valve adjustment

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ann

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Hello,

Hoping for some suggestions! 65 dart wagon 225 1bbl...My #5 cylinder had a MAJOR explosion when I was starting the car one cold morning--blew out the muffler and exhaust gasket at #5. Replaced muffler, adjusted carb/choke. Ran OK, engine sounded a little weird.

2 weeks later, on a road trip, stopped for sandwiches after about an hour. In parking lot, noticed weird clackety engine sound, but still running OK. When starting car, loud clanking noise and won't idle. No useful tools, so limped to a repair shop, and discovered no compression on #5 and #5 pushrod had bent. Adjusted things enough to drive car home. (yes, I do tend to torture my old slants)

Replaced #5 pushrod, checked all and #4 was also slightly bent. Replaced #4 pushrod. Replaced plugs, adjusted valves. Tick. Adjusted valves. Tick, adjusted valves, tick. Irritating tick. Adjusted valves, tick. Horrible irritating tick. Sounds like only one tick, not all cylinders. Louder at slow speeds. Car has power again and seems to run fine, didn't re-check compression because it runs fine. Didn't replace exhaust gasket yet because I might have to pull whole thing apart.

What do you think is ticking? Anything I can check/fix easily to rule things out/in? Where is my smooth running slanted engine? Did I kill the head? Head was fairly fresh--replaced about 2yrs ago.

Thanks for any ideas...Ann
 
You may have a sticking valve, or lifter, or bent valve stem, or something else… hard to know without being there to look, listen, and perform a few tests such as compression, vacuum readings.

As to the explosion at #5, probably carburetor leaked raw gas into intake runner pudding at back side of intake valve when closed, when that valve opened dumped raw fuel into combustion chamber wet the plug causing a miss-fire, and ran into exhaust where it finally lit off from hot exhaust flow and extra oxygen left from #5 miss-fire. There may have been enough fuel to cause a slight hydro lock condition; this is all speculation.

Anytime raw fuel enters a cylinder in any volume it can cause things to bend, and or destroy exhaust systems. Perhaps with fuel filled combustion chamber and intake valve trying to open while held closed by fuel, push rod was weak link and bent.
 
Do a compression test, then I would take a close look at the exhaust manifold.

My dad once put way too much starting fluid in his old 360 truck when it would not start. (key switch was bad)
When it did fire it blew the drivers side exhaust manifold clear loose from the engine block snapping every bolt off.
 
I had a slant 6 that had a small crack in the exhaust manifold, before we found that we reset the valves, seems like 40 times, didn't get rid of the tick till we replaced the manifold, pour some oil down the carb while its running and look for smoke around the exhaust manifold.
 
Exhaust leaks and some mechanical ticks are easy to find. Get yourself a scrap length of hose. fuel hose works OK, heater hose, but more clumsy. When you move the open end of the hose past a vacuum/ exhaust leak you WILL hear it!!! LOL.

You can also "get creative" and add a short length of scrap tube for "more delicate" stuff, stuff the end down the valve cover and listen inside. If the noise is louder, it's not an external exhaust leak
 
OK, thank you all! I'm clean right now for work, but afterward, I'll get dirty and try the hose-listening technique 67dart273, THX. I'm driving it every day. I'm happy my entire exhaust manifold didn't blow off like yours Sireland67, but the ripped apart muffler was pretty impressive.

No hydraulic lifters Oaklacarcollecto. Rockerarm, rockershaft, i dunno, they all seem good to me, but I'm no expert.

It didn't tick until after the pushrod bent, so I feel like it's not the exhaust leak. And it sounds like a nice sharp lifter tick, not a softer exhaust leak. But--I will get in there and see where the noise gets louder by the hose technique. I tried doing it by feel, but it was really hard to identify anything specific. And it was hot.
 
bent/sticking valve would get worse with warm up. Pull valve cover and watch at idle, there should not be much oil up there at idle.
 
Tried the hose trick to locate the sound. Best I can get is that it is in the #4/#5 area under the valve cover. That's where the explosion and bent pushrods were.

Pulled the valve cover, inspected (again), nothing obvious. Observed the running engine and noticed the oil seals on the valve stems are all different. While running, some seals moved up and down, others were stuck up, others were stuck down. Only the seals at the #4 & #5 were moving up and down with the valve stem. Seems wrong?? What holds them in there? Think that's causing the ticking? I've never pulled a head apart before. Wondering if I can fix it without pulling it apart...Is it broken?
 
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