Hit it with some seafoam or marvels mystery oil a day or two before changing it and go easy on it until the change. Both these chemicals that break down carbon. I had an 04 5.3 that this took the tap out for a year.

I like doing it right before the oil change. I am not a big fan of running a engine with additives. I met a chemical engineer that worked for Mobil. One time I asked him what additive he would recommend? Wow that set him off, "If there was a legal way we could improve our product we would do it. Every chemical we put into our oil is tested for capability with each other then people start pour other crap in and next thing you know our oil crap" There are things they could add but they will kill you or smell so bad you would never want to do an oil change. I believe getting rid of smell thing was his current project.

 

Was thinking about trying Marvel Mystery Oil, but several people have told me it can do more harm than good.

 

So what's the final verdict? I've got a similar issue right now. Just started a week after getting my head gaskets replaced. It's always had a little tick but now on some starts it has a more noticeable tick or tap for about a minute. I'm wondering if some gunk got down there when the heads were changed and I think I'm going to change the oil again very soon. Thinking about adding an additive before the change.

 

Haven't done anything yet. Still never has the noise on startup, only later, and only sometimes. Runs great. Changing oil soon, but haven't decided if I'm going to use any additives or not.