cold start tick

why do they tick on cold starts below sometimes 50 degrees but mostly below 30 degrees mine has 74,500 it's a 2002 with the 2.7 ltr in it runs great when driving

 

Short answer is piston metallurgy and sometimes oil thickness. The timing chain tensioner is pressurized by oil and thick oil takes a second to pump up there when cold. Also the 4 bangers use hypereutectic Pistons which are prone to piston slap in cold weather.

 

perfect i did have a chance to take apart the same engine that is also in my truck but that one was blown up and it failed on one of the counter balance shaft bearings and when it was cold had lots of slop on the pistons but the pistons and sidewalls had almost no wear on them at i believe 225k miles