clicking and running ruff after oil change

ok so i changed the oil on my friends sr20det today just like i do on mine.

the car ran fine and strong days before.

After changing the oil and adding lucas oil additives which makes the oil thicker and such. we started the engine to let the oil move around inside the engine and then to check the level. the car warms up and the level comes out perfect and the engine sounds fine we stop the engine . we top up all his fluids and start the engine again this time it sounds like a lawn mover engine and there is a rapid clicking sound ( not very loud) comming from the turbo side of the engine, we taped on the gas to rev the engine up but it was very sluggish and sputtery so we cut the engine. I pulled out the plugs and noticed there was some oil on the threads of the spark plugs but i could not notice any oil inside of the chamber. the oil did not come from out side the valve cover from what i can tell. we did not notice any black smoke comming out of the exhaust but we didnt have the engine running very long when this all started.

what could be the problem?

did the little plastic perforated ring around the oil bottle drop into the valve cover? it happens to a lot of people believe it or not.

Ive heard that a few times. Double check the caps and bottles to see if they are accounted for if you still have them.

You say you had oil on the threads and not on the tip of the plug or anything? Does it sound like its missing?

Why would you run that Lucas crap in winter, that shit turns into glue when it gets cold. It probably lost oil pressure or the oil pump shredded the gear from the oil being so thickā€¦