Hearing a bit of a tap after cooling system repairs

[Fiatlanta]

Started off as a heater valve leak and eventually replaced all the hoses and thermal switch. Finally got everything back together and after a little burping, fan kicked in like it's supposed to and there was much rejoicing.

However...now I'm hearing a tapping or ticking that wasnt there before. Seemed to be associated with a drop in RPMs and slight stutter as the car idles.

In case it matters...I had to pull the front spark plug because I couldn't get the engine to turn over after getting it back together. As it turns out, a wire going to the distributor got knocked loose, but before I figured that out, I pulled the plug to check for spark...engine turned a bit while trying to start. Realized mistake and put plug back...started right up, but then heard the tapping.

Drove it in about 30 minutes to work this morning and didn't have any issues...but still a little disconcerting to hear about "off" sound

[So Cal Mark]

I'd use a stethoscope to determine where the tapping is coming from. Perhaps something fell into the cylinder when you removed the spark plug

[baltobernie]

Are you convinced the noise is coming from inside the engine? Rubber hose or hose clamp striking the engine? Metal heater hose not secure?

[Fiatlanta]

Well it seems to have stopped...it may well have been a screw or piece of trimmed of hose bouncing around and then out.

I'm an EMT...should have thought of the stethoscope trick lol.