I can't think of anything else to do to diagnose. I am literally pulling my hair out, and on the verge of sticking a "For Sale" sign in the back window of the car, all because of the frustration this engine is causing me.

This is the roller motor 5.9L Magnum with a .520/.544 Hughes cam, stock lifters/valvetrain/pushrods, RHS heads, and stock valves.

It has a very loud ticking. Some days I can pinpoint it to the valvetrain, other times, it sounds like it's coming from the carb, and still other times it sounds like it's coming from the distributor or coil. It moves around. But now, there is another issue: the ticking gets much louder than at idle when at about 1500RPM, and accompanying it is a misfire. The misfire can NOT be heard at idle, though the engine does run rough. This is both with an Edelbrock carb or a Holley carb, both 650s. I guess my carb rebuilds could have been bad, and the misfire sounds kind of random, in the way that it's not always a certain cylinder misfiring (I think?).

Since I previous had valvetrain issues, I pulled each valve cover and inspected the pushrods, rockers, and valve springs. All *seem* to check out. I say *seem* because I have no precise measurement tools (nor can I afford any, so don't ask). Summary of the valvetrain:

  • Torque specs are correct on rocker arm bolts
  • Not even a .010" feeler gauge fits between the valve stem and rocker arm
  • No cracks, premature wear, or other damage to note on the rocker arms
  • Lifters look fine visually and don't move when I press on them with a pushrod (I've heard from multiple sources that this is good, and others say it's bad?)


So I decided to check the plugs and wires. The plugs are wet-fouled a little (gasoline, not oil), but they're fine otherwise. No carbon-fouling. The spark plug wires are all in their correct order, and timing seems to be generally good. At least good enough where it shouldn't run really rough. The only problem I do get is that when I pull #4's spark plug boot, I get a nasty shock. Even when I'm holding the silicone. This has happened on another cylinder too (I forget which one) Summary for ignition system:

  • spark plugs minimally wet-fouled, but no carbon fouling
  • spark plug wires are in the correct order on distributor
  • ignition system getting correct voltage and resistance before and after the ballast resistor
  • spark plug wires have a tendency to shock
  • timing is in the general vicinity


I got a semi-credible tip saying that maybe I have a bent valve on cylinder #5 from the bent pushrod and sheared rocker that I suffered earlier (which has since been fixed). Since I don't own a leakdown test kit, I tried a compression check on three cylinders on a cold engine. I checked #1 and #3 first to get a baseline, and each maxed at about 160psi. I then tested #5, and what do ya know, 160psi the darn thing reads. I suppose I could do a leakdown, but I don't know anyone who could let me borrow the kit and show me how to test it properly. Summary of the cylinders:
  • compression on #1, #3, and #5 was all reading about 160psi
  • piston rings seem to have seated, as there is no oil fouling the plugs


Anyone have any other diagnostic methods to find out where the ticking and misfire are coming from?

I fear that soon I will be removing the intake and the head to check out the lifters in more detail, and I really don't have the interest for it. If it comes to that, the car may just be sold or the engine will come out and go back onto a stand and be rebuilt again. I'm unhappy with an automatic transmission behind it anyway.