02 Yukon Making weird noise- New Lifters?

[Lindgren]

So my car is making weird noises as if a stick is under the hood hitting the rim of the tire. This noise is intermittent around 20-30mph and more recently 60-70mph... Took it to the shop and was told I need new lifters? Does anybody know what these are- how hard of a procedure it is- and how much they think It would cost a shop to repair? ..... any advice?


Thanks in advance
Lindgren