Labnerd's theory is spot on - but I feel in the real world all you need to do is change your oil more often if you like to warm it up. Perhaps that would make it severe service instead of normal service? In other words, you guys who still cling to the old 3000 mile oil changes have nothing to worry about.

 

How come ford and my owners manual say never idle for more then 2 minutes in cold weather? not 30 seconds. This is the only info I have seen on here from Ford therefore it is the info that I will use. I also have a feeling the people saying 30 seconds dont actually live where it gets cold.

 

x2 I let my truck warm up until the windshield is defrosted or the engine is above 100*

I know the torque converter doesn't lock up till the trans is above 80* so I try not to rag on it till then, but when it's -20 or colder I'm still showing the exhaust until the engine is about 160*.

Quick Question: How cold is "Cold" ? and are you guys using a block heater? I don't usually need to let it idle until it gets below 0, but it's definitely getting ran for a good 10mins when its -20 or colder.

 

command start on my truck runs the truck for 20min then shuts off. so i usually try to get in before it shuts off.. so about 10-15 min.

 

Good point, OEM remote starters run for 20 minutes. I have a hard time thinking that Ford would have something function so that it could harm your motor and then they would have to replace it.

 

I don't know what to say. As usual, labnerd is providing a good education on the subject with facts, which he as obtained through years good hard work, and at the same time made up opinions dominate the topic. I think we can all learn a lot from labnerd, and I really would like to see all ya all be more encouraging to those who know the facts. Not that I think I'll get my way on that, but that's my opinion.

I think we can all agree that down to 10*F, after 30 seconds, or when the fast idle winds down, then you are good to drive off at a normal pace. It is OK to warm it up longer, but like a lot of things we do with our trucks, it's gonna cost ya. I'm convinced that if you change your oil every 3000 miles and clean up the carbon and sludge with Auto-RX regularly, then you can warm that engine up as long as you want, any time you want with no down side beyond the expense.

It's like those who accelerate hard from stop light to stop light, and brake hard at each stop light. It cost you more in gasoline and brake pads, but many of us do it every day. I did it yesterday.

 

^ my "opinion" is not an opinion, it comes straight from mine, yours and everyones owners manuals. If warming it for more then 30 seconds could do serious damage then the owners manual would say not to warm it up for more then 30 seconds. It says 2 minutes so that is the longest I warm it up for. I will take Fords word for it as opposed to someone I dont know on the internet.

 

Since I'm an apparent idiot in the field, here's a link from Modern Tribology Manual which is available via Google books so you can research it and read it for yourself. This section, 32.7.3.4, is titled The Effects of Service on Engine Oil Properties. The pertinent part in regards to this thread is fuel dilution. You'll read as it refers to Fuel Reaction Products. Besides those listed you will have the cleaning agents in the fuel, dewaxing agents from the fuel making process, any ethanol, any anti-knock compounds, octane enhancers, etc. You will see the term Nitration. Nitration is the direct representation of combustion efficiency and is a measure of the combustion gases exposed to the lubricant, including those in a blowby condition.

Another issue that has not been discussed in this thread is that an engine that idles is not doing any work thereby is much slower to warm. The slower an engine is to reach temp the more water it will condense out of the incoming air charge. Sludge is the product of water that cannot be cooked out once the engine reaches full temp via the PCV system. The sludge will build hot spots in the engine resulting more varnish(the sticky brown stain) than the engine might be able to handle. Those in particular with the 5.4 3V engines- this is important to keep the runners clean and working as well as the full range of the phaser. If you think you must idle, at least put it in drive or reverse to make the engine work some to help it heat up.

For those in the extreme cold, buying an oil by favorite brand or advertising hype is not a good thing. You need to know the CCS rating of the oil you are using. Every oils CCS (Cold Crank Simulator) is posted on the makers website. In this test of the oils ability to be pumped at cold temps, the lower the number at the given temp is better. DO NOT assume that if you use a 0w-20 that it will flow better at cold temps than a 5w-20 oil. That's not always correct and not all oils are created equal in this arena. Always use the CCS rating when choosing a winter oil for extreme cold. Any oil with a Xw-XX rating is the SAE rating, not the actual viscosity performance rating.

Here's the linky to the book and you'll need to scroll down for the listed section:
http://books.google.com/books?id=h6X...formed&f=false

 

how about we just drop the topic before I add some more people to my ignore list...

 

[QUOTE=Labnerd;4512731]No. You assume that the fuel stays separate from the oil and burns off as the engine heats up. It does not. Think a minute glc, I know you are fairly sharp about engines and oil. Both oil and gas are hydrocarbons from the same base source. When mixed together, they stay mixed together. You'll burn off the aromatics in the fuel after several hours of driving after one cold startup and letting it idle but you'll never burn off all of the fuel hydrocarbons. That's why you'll see the fuel in oil analysis. It's for this same reason that you'll find that an oil is said to shear out of range during the winter months. It's not necessarily shearing but dilution depending on how much fuel has actually gotten dumped into the oil vs actual shearing. And remember the specs on a 945 or 930 oil while thinking about this. And remember the old days of using a heavier oil when towing? It wasn't that the engine built more heat and needed it. You used it because the carbs were notorious for dumping fuel into the combustion chamber where not all of it was burnt and you ended up with loads of gas in the oil reducing actual viscosity. It did not burn off like you think otherwise, we would not have seen folks changing motor oil at 3000 miles. The days of carbs are gone but the 3000 mile oil change lives on which is a waste.

A lot of you posted opinions and your certainly welcome to an opinion but I posted facts. It's your engine, your money, drive it how you like but the original poster asked a question and I answered it with facts, not an opinion. And I could give you even more facts about the forces causing varnish and sludge that are more prevalent in a slow to warm engine than a quickly warmed engine. But no one seems interested in facts anymore.[/QUOTE

what makes you think you will "burn of the aromatics" but never all the hydrocarbons in the fuel?? If you think the aromatics will burn why not the lighter olephinic, naphthenic and pariffinic hydrocarbons that gasoline actually consists of????? And to say that hydrocarbons never separate is also laughable.....if they NEVER separated we would never get gasoline or kerosene or anything out of the crude oil it would just stay crude oil.

 

He meant in your engine. Unless you have a refinery in your oil pan.

 

gasoline boils at a low temp, lower then what is being produced inside my cylinder walls. The heat alone would boil it off . Its funny you pointed the not important part of my comment out as well. Why not tackle the first question there big guy???

 

Not concerned with your cylinder walls. We are concerned with dilution of what is in your oil pan. You missed the point and your post did not help your case little guy..

 

Here's my oil analysis done after 15000mi of running 5w-20 Royal Purple and a K&N Filter. This includes excessive cold (-40) starts and months of warm-ups. If you can give me a more extreme place to test a vehicle, let me know.

Fuel is at the bottom.