Engine knock

My 2012 Tacoma 4 cyl has a knocking/pinging noise when I start it on cold mornings. My 06 Tacoma had same engine with 126000 miles and never did this. I change oil every 5000, use syn. Mobil 1, 0-20. 115000 miles on 2012. Only does it on cold mornings, never in the summer. Please chime in. Thanks

 

Mine did that just this morning, cold starting at about 7 below zero. I usually plug it in when it's cold out but not always. No worries, just the sound it makes before the oil pressures up and gets where it needs to be.