While engine is running there is a ticking noise comming from the lifter.
how to fix if Engine has a ticking noise. on 2003 GMC Sierra 1500 HD
Next oil change try using Mobil 1 synthetic because the same thing happened in my sons Trans Am we were using Valvoline 10w-40 and we had one lifter sticking then we switched to Mobil1 10W-30 and that solved it www.mobil1.com and its available at Walmart in 5 quart jugs
If you have upgraded this vehicle then you might need to run a higher octane fuel to solve the problem