Need help!!! Oil in cylinders!!

[MastaSplint]

So I'm helping a friend out. He has a 240 with a red top sr20det motor in it with the factory turbo, just boost is turned up thx to a boost controller. He was out driving yesterday and clutch kicked it in first gear to drift a bit around. Corner and everytime he does it he hits the rev limiter but has never had any issues. Well yesterday after doing it he started to get a loud knock coming from the motor. His oil was very low, like a quart was all I drained out of it and he had only 5w-30 oil in it instead of the thicker oil like he should be running. Any case after drained the little oil in there we added 15w-40 and went for a drive. The noise is still there and just as loud. At first u could only hear when reving the motor now you can hear it at idle too. I took his valve cover off and cylinders 1,2,3 all have oil in them. 1 has a little, 2 is halfway covering the spark plug and the 3rd has so much oil u can barely see the top of the spark plug. Any ideas what could cause this? Before I took anything a part it sounded like rod knock but now that it's all part I'm wondering if it is a bent or broken rod or something else. Please help. This is a daily driver and we need to fix it right away. I know we gotta take the head off to investigate more but any help now would be great! Thx in advance.

[PapaSmurf2k3]

The oil in the spark plug holes is probably caused by a bad valve cover gasket.

Running the vehicle that low on oil and bouncing off the rev limiter can definitely cause all sorts of major damage though. Bad bearings, excessive cylinder wall/piston ring wear, etc.

5w30 is the correct oil too... why would you run thicker?