I have a 2003 Silverado 5.3 that I just hit 121k miles with and I believe I have a lifter knock. It just started happening about a week ago after I got back from a 600 mile road trip. Upon returning I did an oil change and thought that might fix it but I've put 350 miles on it and it's still there. No power loss or change in idle. Any quick fixes? I saw a video on running auto trans fluid mixed with oil for around 300 miles and that fixing it. First time chevy forum user so any tips or advice is welcome. Thank you!

 

I absolutely recommend the ATF with the engine oilMy father used to substitute a litre of engine oil with ATF all of his yrs and we never had any issues with lifters
I remember buying a pickup from some dude yrs ago because he had a lifter tick and dad got it cheap so right there in the buddy's driveway my dad dumps the oil and tops it up with ATF headed for home and part way back bam noise gone it was so funny but it works

 

Ok great. Do you leave the ATF in there for the life of the oil change like 3-5k miles? I just finished doing a seafoam treatment and tomorrow I am doing an oil change with a better higher quality filter and some better oil. I'm going to try the Rislone treatment in this oil change but If this doesn't work I will definitely try the ATF. Thank you much appreciated!

 

I leave the litre of ATF in for the duration of the oil change it is also a awesome cleaner to so it asks just like sea foam.........