I bought my 6.4 in May and it hasn't got cold here in Fla. until today. When I fired her up this morning the outside temp was in the 40s. I noticed a little tappet noise for the 1st mile or so then it disapeared and the engine sounded fine. Is this normal for the 6.4 ??

 

I live in BC and had 15F to 50F temperatures last winter and this fall. I have 16000 miles on the 6.4 PSD. In all those miles. hot or cold temperatures, I have never heard any tappet noises.

 

Do you let it warm up for a good amount of time?