I know there are very few 3.7L owners here, but maybe someone's heard of this before. I searched 3.7 and 3.7L and couldn't get any results. When my wife starts her truck(08 1500 3.7L/6 speed manual/2 wd) on below freezing mornings, it sounds like there is a camshaft tap. Not valves or lifters, I know that sound well. It sounds like when I had a 3.0L Mitsu engine and a cam lobe had a small worn spot that would tap as it contacted the valve on rotation. It may be absolutely nothing and just part of the normal warm-up process on these new engines, but the oil level is fine and it runs perfectly, so I just don't know. Anyone have any idea or maybe someone has heard something about it? Also, after reaching normal operating temps, it goes away completely and it becomes the quietest 6 cyl I have ever heard again.

 

You could always try different oil

 

That could well be. I normally use 15/40 in everything I own, but the dealer is giving 2 years LOF's for free and will only put that thin, runny 5/30 in it.