[nUcLeArEnVoY]

Originally Posted by pippintook

UPDATE
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Original issue was a ticking/tapping noise. Engine was stock 400. Noise was happening February when the temperature was around freezing. Oil used Rotella 10w-40. Noise initially was happening on cold start.

Some good tips for anyone that gets similar noise

(i) Use a device to help hone in on the location of the noise. I used a Steelman EngineEar which is an Electronic Diagnostic Stethoscope. I also used a long rubber hose. I determined the noise was coming from drivers side.

(ii) Pulling valve cover and looking for anything amiss. I pulled drivers side valve cover and everything looked good. With valve cover off , I was able to get more focus on where the noise was coming from - for me, it seemed most of the noise was around intake valves on cyl 1 and cyl 3.

(iii) Putting small red line on pushrods and making sure they are spinning and oil coming out the tops of all pushrods. All my pushrods were spinning though one cylinder
was slower and I had one pushrod that was a bit erratic in spurting oil.

(iv) Monitoring engine vacuum. For me engine vacuum seemed mostly ok - though possibly a little erratic. At fast idle (1400rpm) - I was around 20-21" and at idle (750-800rpm) I was around 18".

(v) I used Schurkey's great tip for shorting the ignition wires. I was able to short all wires on driver's side (cylinders 1-3-5-7). When shorting each a cylinder via the copper wire in the HEI cap, the engine just seems to die a little - and the vacuum gauge drop about 1.5" of vacuum and become a bit more erratic.

So, after doing all the diagnosis, I was thinking I might need to do a tear down and inspect further. I had a bottle of Marvel Mystery Oil and a about half a can of Seafoam on my shelf. I added about 16oz of Marvel Mystery Oil and 8oz of Seafoam to the engine. I started getting minimal or no tapping on cold or warm engine. I did a number of test starts/runs with no tapping. I let the engine sit and started again and still no tapping. One thing I also noticed was that the one pushrod that was spinning slower was now spinning fast
and I was not really seeing any erratic oil spurts out of the one pushrod.

I reassembled everything (new plugs, new rotor and dist cap) and took for test runs - still no tapping. I drove around for maybe 200-300 miles with the Marvel Mystery Oil and Seafoam in the oil. Engine ran fine and no tapping. I changed the oil and filter and put in 10w-30 and engine is running good - no tapping. So, good news - it seems Seafoam and Marvel Mystery Oil did help (at least for me and for the time being).

Thanks for all the help

Sometimes that's all it takes, man. Glad that MMO swept in and saved the day. I used Rislone Engine Treatment concentrate on mine prior to a recent oil change and it improved my sticky lifter a lot. Still happens from time to time on a cold startup but it always goes away after a few minutes. Every year I change my oil, I never see metal a,nd I've not seen a progressive drop in my oil pressure over the years so I'm not going to find problems that aren't there. I'm already a nervous anxious wreck as it is.