Hi Scotty I have a 2005 Tahoe with 175,000 miles. About every other time I crank it up cold the motor has a tapping sound on the left. After I drive it for a few minutes and it gets up to temperature tapping goes away and I can drive it hundreds of miles at a time with no noise. I have always changed my own oil with Mobil 1. I have tried Seafoam in one oil change, Rislone cleaner in one and now have Hot Shot stiction eliminator in this oil change now. Next oil change I am trying Liqui Moly hydraulic lifter additive. Any Thoughts? Frustrated in Brenham TX.....
It will probably run just fine with that lifter tap for another 150k miles. Honestly your doing well trying the mechanic in a bottle stuff trying to quiet it up. I have had the best results of adding a half quart of Lucas oil stabilizer after I change the oil. Those 5.3 ones will usually outlast the transmission and rear end two fold.
@cjbman
Thank You