This past Sunday afternoon, I started my 05 Nissan Xterra 2wd like normal and started hearing this ticking sound come from the engine. It sounded like it was coming from under the intake manifold. I checked the engine oil and it was full. The next day I took it to my local mechanic and they said it's internal engine damage. They said with the amount of miles on the truck (287,000), it wouldn't be worth replacing the lifters. I've regularly changed the oil every 3k miles and maintained the vehicle well for the 150k miles that I've owned it. They said the lifters were not hydraulic but instead solid and shimmed and they would have to send it to a machine shop. The options they gave me were to either replace the engine with another used engine or just keep driving it until it stops. Needless to say, I love my truck and want to fix it myself if I can. I just don't know what replacing the lifters would involve so I'm asking for your honest opinion of what I should do. Thank you for your time!
With that kind of mileage, you're just guessing on what the noise is often. It's not the lifters but the cams themselves which cost a fortune to replace. I'd say drive it till the drops and if you like the vehicle put in a rebuild engine then
I have a friend that mentioned it could be the VIAS power valve actuator that is controlled by the intake manifold runner solenoid. He said sometimes the power actuator that goes into the intake manifold has a butterfly and it can become loose and that's the rattling that you hear.