Hi folks,

What do you believe is a proper warmup procedure for your trucks equipped with the 6.7 Litre Diesel engine? This applies to year round driving, not just cold weather driving.

I have been thinking about this issue and another thread touched on the edge of the issue. I have not found another post directly on this topic. In my opinion, letting an engine warm up before asking it to do hard work results in better performance and long engine life. I have done this with vehicles, farm tractors, small engine powered equipment, off road atvs, outboard boat engines, and airplanes.

I have an F-350 with the 6.7 Litre Diesel engine. I do not yet have the high idle setup. I would like to know how you use the high idle for warming the engine.

I live in the country so the county roads are paved and the township roads are not paved. Therefore driving anywhere involves some slow driving initially. Then it is onto state routes. For normal driving, I let the engine run for 5 minutes to let everything to start warming. Then I drive moderately until the engine gets up to normal temperature. When pulling a light trailer I do the same. When pulling a heavy trailer I let the truck idle while doing last minute binder and tire checks, locking doors, and closing gates. Then it is usually getting warm and showing on the gauge, so I start out moderately until the engine is fully warm.
I would like to setup the high idle and wait until the engine is fully warm when pulling a heavy trailer.

The truck has a few real luxuries for cold weather driving. The heated steering wheel at first sounded silly, but it is really nice. Heated seats feel great on old spine injuries. The supplemental heat gets the cab gets warm right away.

So what do you folks do?

 

The warm-up notion is old school IMO. I listened to a talk from a Ford powertrain engineer who said that Ford engines are ready to go within 20 seconds down to a temperature of -20 F. Back out of the garage and you are ready to go.

 

Your owner's manual is an exceptionally good resource here. It reduces opinion to explicit guidance on cold weather operation. In my 2018 manual, it begins on page 178 under the heading: STARTING A DIESEL ENGINE - 6.7L DIESEL

The manual is fairly comprehensive and tends to agree with how you are doing things. It's a good read and I highly recommend it.

 

IMHO, idling for 5 minutes doesn’t do anything but waste a few ounces of diesel. I’ve noted that driving for 5 minutes might not get the oil temperature up to 100°F on a 50° morning.

I just start mine and let the oil pressure come up while I buckle my seat belt and fold the mirrors out. Then I’ll drive it pretty easy until the coolant and transmission temperatures (the temps that are always displayed on my dash) are both above 170°. Really though, I don’t worry much about it at all since I drive it pretty easy all the time anyway.

 

I've started and let it idle 5 minutes and it still doesn't get warm. I've started and gently driven out of the neighborhood and up to the freeway on ramp. Again 5 minutes and my temps have all reached almost normal. These diesel engines don't produce any heat unless there is some turbo boost. EGT's at idle are less than 300° Just easy driving ( 25 mph ) and you get EGTs up to 500°. Even high idle doesn't create heat. You need some turbo boost to push up combustion temps, which in turn warms the block, coolant, oil. etc.

 

Once its running its moving .. In my neighborhood, I usually roll at idle speed to the first stop. After that its game on.

 

I let any engine run for at least a minute, before moving them. When it’s cold outside, I start it in time that the cab will be warm, when I sit in it. Remember, even if your engine is up to operating temperature, a wide variety of bearings are not.

 

Which bearings? How are they affected by cold weather? How do they fit into the warm up scheme and how do we address this issue to avoid abusing them?

 

This is the only reference I found regarding idling upon startup in the Ford Manual for 2017 F350 Diesel engine


STARTING A DIESEL ENGINE - 6.7L DIESEL
Read all starting instructions carefully before you start your vehicle.
For temperatures below 32°F (°C), the use of the correct grade engine oil is essential for proper operation. Refer to engine oil specifications for more information. See Capacities and Specifications.
Your vehicle may have a cold weather starting strategy that prevents severe engine damage by assisting in engine lubrication warm-up. In extremely cold ambient temperatures, this strategy activates and prevents the accelerator pedal from being used for 30 seconds after you start your vehicle. A message appears in the information display as your vehicle warms up. By not allowing the accelerator pedal to be used, the engine oil is allowed to properly lubricate the bearings preventing engine damage due to lack of proper lubrication. After the 30 second warm-up period, the accelerator pedal will be operational again and a message appears informing you the vehicle is ok to drive.
When you start the engine in extremely cold temperatures -15°F (-26°C), we recommend that you allow the engine to idle for several minutes before you drive the vehicle.

 

Thank you for the information and opinions. Even though the truck may be ready to roll after a 30 seconds, a minute, or a few minutes I will continue to let it warm up a bit before driving easy to get everything up to operating temperature. I will continue to give it more time to warm up when pulling a heavy trailer.

Different but similar, I let my tractors warm up before doing heavy work and have had very good reliability and long lasting engines. Again very different but similar if you have flown an airplane the engine must be warm before takeoff. Better for engine longevity and safer than pushing takeoff quantity of fuel into a cold engine.

My ideas may be old school, or waste a bit of time and fuel. But if I must rush somewhere, it better be the hospital because otherwise I am not going. I quit rushing the day I retired. I do things and run my business at my desired speed. I usually hustle, but I control the throttle!

 

Wheel bearings, for one (4) example. The grease typically used is rated down to -40*F. Timken offers a synthetic grease with an operating temperature to -50*F. The bearings themselves are generally rated to -65*F. Normal operating temperature is somewhere around 120-150*F. Yes, these are extremely cold temperatures, but applicable to must if the US, at one time, or another.



Even in not as cold temperatures, your brake pads and rotors work better with some heat in them. Rear axles sit in a pool, but the top is dry and the oil not at optimal operating temperature until you’ve started driving and got some heat in the fluid, as a couple of examples.

It’s been known for quite a while the rich condition electronic fuel injection creates, to get an engine warm is bad due to fuel wash, in the cylinders. The excess fuel tends to contaminate the engine oil. Oil analysis’ that are heavy on fuel usually come from vehicles frequently driven short distances. All the parts don’t get warm enough to burn it off and it stays in the oil. People tend to only think about the engine. Really, the engine will take care of itself. It’s one of the few systems that can make adjustments.

The best thing you can do is take it easy and drive. This will allow all of the systems to generate heat at around the same ratio. What is really bad is when people warm up their vehicles and start driving hard, not realizing the coolant gauge isn’t indicative of the overall operating temperatures. Fortunately, today’s vehicles are incredibly good. Even getting in and romping on them isn’t an automatic death sentence and they can take a lot of abuse, before problems are created.

 

I generally let my tractor warm up for several minutes, before I move it. In that time, I do things to get the hydraulic system warmed a bit. Move the bucket, backhoe, etc, to get the hydraulic pump moving. Mine is a HST. It seems to drive better with warmer fluid. Conversely, when it’s hot out, I’ll cycle the backhoe fluid (when I’m not using the backhoe) to bring some cooler fluid into the system.
Even when I start moving, I go slowly. The front axle is lubricated by a pool of oil that leaves the top of the wheel drives exposed. Until I’ve gone a few wheel rotations, I don’t put it in 4wd, if I can help it.

 

So if its -14 you dont have to wait several minutes? Kidding!

 

Give it time. Some people are so “by the book” they’ll tell you -14 is no different than 100. Because the book says “-15”.

 

A coworker with a 2012 F-250 was told by his diesel performance expert that idling a cold 6.7L creates soot that will contribute to plugging the EGR. He was an avid user of his remote start and his EGR system plugged up last year at about 140,000 miles. It was going to be $2500 to repair it. He did something else.