Hey guys and gals, I have a 04 tundra 4dr with 63,000 miles on it. Recently I noticed that I was getting a knocking noise from the engine upon starting it up. Now the noise has progressed and I hear it all the time. I figured it was a lifter and took it to the dealer where I purchased it, who confirmed it was a lifter. Due to it being out of warranty I decided not to get it fixed that day. Can any of you tell me if you have had similar problems with with this type of truck and if so is there a simple fix like one of the oil additives, (sea foam, marvel mystery oil, ams oil additive) or do I need to bite the bullet and have it replaced (which I understand is a fairly costly job on these trucks). thanks for the input.