Warm-up procedures when starting from a cold start?

UUMMM idle to warm up,, idle to cool down ,which is it?
When does the ''cool down'' start?

 

I run my APU. Its keeps the battery topped up, and the engine warm.

 

When you get off the highway with a 900 degree turbo... and wait for it to cool to 300 so you dont flash the coolant.

 

Throw some fire, literally:

 

Makes perfect sense. Lot's of dissimilar metals between the block and various internals. Aluminum reacts differently than cast iron and so on and so on. Many years ago on this forum I read Mr Haney made a comment that you could possibly sink a liner by not allowing one to warm to at least 160* coolant temp before pushing it so that has always been my rule.

I won't move the truck until it hits 160*, not even bobtailing. I start it, let it run about a minute, then bump it to 1,000 rpm. In the summer it might hit that temp in about 10 minutes. In the winter about 20-25 minutes.

 

Why do so many bump the rpms up to around 1000 so soon after startup instead of just letting it idle at 600 or so to warm?

 

Get cylinder temps up faster and get more psi in cyl to get rings to seal in cylinders better less blow by and fuel dilution in oil. Faster warm up. Faster the warm up and less blow by the better for after treatment.

 

Because they think they are driving a mechanical engine from 1970. They can't grasp that engines have a higher psi oil pump among other things now days.
The only reason to go a high idle is to make more heat, for like in the winter or such.

 

I have a new engine from Cummins. I idle at 850 rpm for about 10-15 minutes for a warm-up on a fair day. Cool down same thing with the fan blowing. Cummins recommends doing a warm up and cool down on these new engines per owners manual.

 

This discussion makes me miss the pony motors on Cat equipment.