warm-up procedure...

[Bob W]

What is the best way to warm up the engine?
On page 120 of the 2001 owner's manual, it states: "Allow the engine to idle at fast idle for about three minutes until the manifold heaters have completed the post-heat cycle. "
On page 125: "When starting a cold engine, bring the engine up to operating speed slowly to allow the oil pressure to stabilize as the engine warms up. "
On page 126: "No-load engine speeds should be kept under 1,000 rpm during the warm-up period, especially in cold ambient temperature conditions. "
Do I see a slight contridiction between the statements on page 120 and 126, or am I reading too much into it?
As soon as the oil pressure is up, I idle at around 1100-1200 RPM until the heaters stop cycling. Is it necessary to wait until the cycling is complete? Also, what exactly is "high-speed, no-load running of a cold engine"? which the manual says to avoid.
Thanks for any clarification.

 

[LSMITH]

Bob, they mean let the computer idle the engine up, it will idle the engine up about 100 RPM over normal. Page 126 is trying to keep you from adding more fuel to a cold cylinder that can't burn it. By bringing the RPM up to 11-1200 you are pushing fuel into a cold cylinder and it will not burn all of it. The fuel that doesn't burn is washing the oil from the cylinder walls and getting into your oil, so don't do it. I rev up to 1100 to COOL the engine off before shutdown after a hard run and it works very well. As soon as the oil pressure stabilizes I drive away slowly. After a mile or so I bring it up to speed slowly, and wait for the temp needle to come up. When the temp needle gets to the bottom of the normal range I drive normally.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S SPA Boost/EGT Everything but leather NRA Member Great Lakes TDR Member

 

[Bob W]

LSMITH,
Is it correct to say that the best thing is to let the computer control the idle during the heater cycles, and then drive as you describe until the gauge registers the low end of normal?

 

[LSMITH]

Yes Bob, that is what I would recommend.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S SPA Boost/EGT Everything but leather NRA Member Great Lakes TDR Member

 

[David_VT]

I've noticed that having AMSOIL on board has changed the cold weather 'feel' of the truck big time.

Last winter it felt like the cylinders were coming 'on-line' one at a time, while the power steering pump was squealing like that pig on 'survivor'.

This winter, even when the cab seats are rock hard and the snow is 'crunchy', one cycle of the wait to start is all I need to get it running. None of that wicked roughness. I wait for the oil guage to come up and I am good to go.

FYI the 'pig' died and was replaced at the end of the warranty last month.

 

[Ladders]

Just another way, I turn on the e-brake and let the exhaust come up to 300* before leaving, at idle. Go about 2 blocks this way then at main hwy. Keep it under 1. 5-2k rpm till the temp is up (about another mile or so), e-brake on all the time till about 3-4 blks from shutdown spot. Of course, if you want more ways, do a search thru all the forms. Depends on the low temp as to how we all do it - I use the block heater any time its under 50 and its on a timer for about 2 hrs (variable leaving time) during the "winter". Probably in another month, wont worry if it gets under 50 for a few nites.

SOTSU!!
\\BF//