Knocking/ticking Sound

[rimares]

2000 GMC Sierra v-6 replaced the oil pan gasket and cleaned the pan that had about a half inch of sludge, afterwards was fine for about two months, now it's ticking on a cold startup then after about 5 minutes goes away. what could it be?

[Sierra in the Sand]

2000 GMC Sierra v-6 replaced the oil pan gasket and cleaned the pan that had about a half inch of sludge, afterwards was fine for about two months, now it's ticking on a cold startup then after about 5 minutes goes away. what could it be?

 

It's undoubtedly a leaky hydraulic lifter. They bleed down as the truck sits, then usually pump up quickly when you restart. Annoying, but probably harmless.