Dirty Box

Torture test with negative temperatures in the morning. No tapping noise and purrs like a kitten on startup.

webejeepin

Here comes a newbe question...why does the oil drain back? I never really noticed it until now.

-10c no block heater I hear a few seconds of tapping then done nice and quite

Same temp even colder -20c this week block heater plugged in... No tapping purrs right when I turn the key

Always used mopar filter and 5w20 Dino

Never makes this sound in spring and summer

Will be using my block heater more in these temps

Dirty Box

It's called lifter bleed down.
Here's a great explanation from
http://ls1tech.com/forums/generation...leed-down.html


In order to understand lifter bleed-down, you need to understand the purpose of hydraulic lifters and how they work. Here is how I understand hydraulic lifters: A valvetrain with solid lifters must be carefully adjusted to contain a small amount of play called “valve lash”, to allow for thermal expansion and to allow the valves to close fully. This necessary looseness causes noise and wear. Hydraulic lifters automatically adjust valve lash to zero, thereby reducing noise and wear. A hydraulic lifter is a piston within a piston. The outer piston is the lifter body; the inner piston is called the plunger. The plunger is retained inside the lifter body by a snap ring at the top of the lifter. There is a compressed spring under the plunger. The plunger is free to travel up and down in the lifter body so that the lifter can adjust itself to the size necessary to eliminate valve lash. The bottom of the lifter rides on the camshaft. The pushrod rides on a cup in the top of the plunger. When the lifter is on the base-circle of the cam, oil passages are aligned so that the chamber in the lifter under the plunger fills with oil under pressure. The oil pressure and the area of the bottom of the plunger are such that the lifter expands with enough force to eliminate all play in the valvetrain but with insufficient force to open the valves. The lifter then behaves like a solid lifter because the oil resists compression and the passage by which the oil entered the lifter is closed soon after the lifter begins its upward travel. In order to accomplish all this magic, the plunger needs to rest somewhere away from its travel limits within the lifter body. This is a mechanical adjustment called "lifter preload". We are now at the point where we can understand lifter bleed-down. Bleed-down is simply the relaxation of the lifter when the engine is shut down and oil pressure is removed.

When it gets cold it takes longer for the oil to fill the lifters, so the two pistons collide and make noise.

Block heater should help.

HankFard

Atta boy! Well done and continued good luck.