Posts: 715
Threads: 49
Joined: Apr 2014
One section that I found to be extremely pertinent was about idling.
"Before discussing reasons not to idle a truck, it might be a good idea instead, to discuss when and why you should actually do so. Some people are of the opinion that idling a truck at all, for any reason, is a bad thing. When it is cold outside, warming your engine up slowly before putting it under a load is always a good idea. Rapid expansion of exhaust components, including your turbo or EGR cooler, is never good. It can cause mechanical stress and cracking. On really cold days, it can take as long as 30 minutes, witch gives you plenty of time to plan your trip, or get caught up on logs, paperwork, etc. Is it worth the half gallon of fuel? Definitely. When you are pulling a heavy load, or climbing a hill, everything on the exhaust side of the engine heats up quite a lot, like the turbo, exhaust manifold, piping, EGR cooler, and anything else mounted to the exhaust system or engine block. When your engine is running, the coolant wicks away the heat, keeping everything from overheating. If you have just climbed a hill, or are using a lot of torque against a strong headwind or slight incline, and you are heavy, some of these components, like the turbo, and exhaust manifold, can easily get upwards of 800+ degrees. If you shut your engine off when the components are this hot, the coolant will stop flowing, and the extra heat has no where to go. That heat will bleed back into the engine block possibly causing the engine and turbo to overheat even though it is switched off. Most often, your turbo is the one to suffer the most from this. The oil that keeps the blades spinning carbonizes inside the bearing, shortening its life considerably. How you prevent this, is that when you have to stop at the top of a hill, or pull off when the engine has been working hard, is to let the truck idle for a minimum of 3 to 5 minutes. This keeps the coolant flowing and allows the turbo, EGR cooler, and exhaust manifold temperatures to balance back out again. Drivers of newer trucks have gotten so used to shutting off their engines as soon as they stop, that several of the turbo manufactures now list this as one of the biggest causes of premature turbo failure. This is also one of the theories sometimes used for repeated EGR cooler failures. An example of this overheating problem can be seen quite often in the newer DD15 Detroit engines. The starter is located on the exhaust side of the engine near these components, and it is not uncommon for the starter to get hot enough to overheat after the engine has already been shut down, causing the truck not to want to start sometimes for 30 minutes up to as much as 2 hours. I have seen many drivers stuck at fuel islands with a Cascadia that will not start, giving no indication as to why. Half an hour later, when the tow truck arrives, it starts right up again, making a liar out of the driver and wasting a service call. Ironically, many Detroit dealers and mechanics will refuse to believe that this is the cause, and, quite often, the truck ends up in the shop several times before the starter gets replaced and the problem gets solved. What does all this mean to an owner-op? Well, if your truck is very hot, or overheated, let it idle for at least 5 minutes so that the temperatures can balance out. If not, you may just end up regretting it later."
Jon & Chris Everton
1986 40' Dog House #86
450 hp ISM 5 spd ZF Ecomat 2
2004 Range Rover L322 Toad
