High Fuel Mileage and Great Running Diesel Engines
At least once a day, I get a phone call from someone asking, “What kind of truck should I buy?” Being I have never met most of the owner-operators I speak to each day, I have to ask many questions, such as: What do you haul? What type of trailer? Where do you live? What speed do you like to drive? What is your preference of trucks and engines? What is your height, weight and age? This is how I get a mental picture of you and your operation. This past winter, I received a phone call from DuWayne Ehrke who lives in Wisconsin and wants to get back into trucking. He was asking for help building a high fuel mileage truck. His trailer is a reefer and he runs between Wisconsin and Texas. With his size, I recommended a T600 Kenworth with a DD4 Detroit Engine. This engine was produced between 1998 and 2002, so it’s hard to find a cherry that is 10-14 years old, and you have to be mechanically inclined to be able to rebuild a truck with well over one million miles on the odometer. Well, DuWayne is mechanically inclined and found a 1998 T600 with 1,300,000 miles on the odometer and about 260,000 miles on an in-chassis overhaul. Needless to say, the truck needed a lot of TLC and is a work-in-progress in motion. DuWayne asked me what he needed to do to make this truck fuel efficient, and so here is the list of what he installed before his first trip: Pittsburgh Power re-worked ECM, crankshaft damper and mercury-filled engine balancer, ported ceramic-coated exhaust manifold, 15% larger performance turbo, FASS Fuel System, new fuel lines, Fleet-Air Filter, OPS By-Pass Oil Filtration System, Micro-Blue wheel bearings, and the Micro-Blue 2:64 rear gears. The truck is equipped with a 10-speed transmission which I don’t care for and would prefer a 13 or 18 speed so he would be able to split the gears if need be. However, for now we are working with the 10 speed and he is driving it in 9th gear, which is direct gear. 10th gear is now used just for bob tailing or if you just want to flat-out speed, which we all need to do sometime! For the most part, driving between 58 and 64 mph is where we will obtain the best fuel mileage. When you are on rolling hills, you now must use some speed to run the loaded semi like a roller coaster. The 58 to 64 mph is for level terrain.
So now DuWayne is loaded with cheese heading to Texas and there are problems with the ECM talking to the engine, so a stock ECM has to be installed on the truck. The truck ran fine, obtaining 8.8 mpg going south and coming back north with a load of eggs, he obtained 8.4 mpg. I think this is great fuel mileage for an old KW with 1.3 million miles on the clock and its first trip. We knew there were electrical problems and needed the Kenworth at our shop for the electrical engineers to diagnose and repair the problems and install the performance ECM. Now the problem is DuWayne is busy making money running to Texas and back. He did take time off to come to the Owner-Operator Snowmobile Conference in Togwotee Pass, Wyoming. At the conference, we talked about getting this truck to Saxonburg, PA, and he said he would make it happen. Well, he finally got a load heading our way and arrived July 30th. We began diagnosing his KW and found a bad turbo boost sensor and some other wiring issues. Fernando installed the performance ECM and gave it an additional power upgrade and this is what Du-Wayne had to say: “The trip to Pittsburgh Power was well worth the time and then some 10-fold. The trip should have been made 4 months ago before I put the truck on the road. The cost of lost fuel mileage and the aggravation of a poor-running truck make for long days and short nights. Every driver and owner-operator knows a good mechanic. They take care of most of the issues you have. Then, you come across a GREAT mechanic and they fix ALL of the issues and WOW! What a joy to drive again! Listen to the experts. You will not go wrong. Now I’m in my first trip and all I can say is WOW. Why did I wait so long to get it repaired properly?! Bruce, you should have smacked me upside the head at the snowmobile conference!”
Many times, problems are blamed on ECMs, and yes, bad programs will cause you a loss of power, a loss of fuel mileage, and aggravation. However, wiring issues and sensors can’t be fixed over the phone so that is why we tell you we need to see the truck. Before we had computers in trucks, we had to diagnose engine misses with our fingers and you still can do this with an electronic truck. Where there is a miss and the engine is cold, tilt the hood and start the engine. With both of your hands, using your index finger, touch the bottom of the exhaust manifold. Starting with cylinders no. 3 and 4, feel the heat. Then, check cylinders no. 2 and 5, and then no. 1 and 6. You must touch them in this order, always 1 and 6 together, then 2 and 5, then 3 and 4. The 2 center cylinders will get hotter first because they have the most exhaust coming past them and then 2 and 5 will be next and 1 and 6 will take the longest to heat up. The cylinder that is that remains coldest the longest compared to its partner is the cylinder with the miss. If you are coming off the highway and the engine will be too hot to touch, then get 2 rags and a bucket of water and touch the exhaust ports while the engine is running with the wet rags, and watch how the water evaporates. After you touch the exhaust ports several times, the manifold will cool down enough for the cold cylinder to stay wet longer, and again always compare 1 and 6, 2 and 5 and 3 and 4 together. The cylinder that stays wet longer will be the cylinder with the miss. Then, if you want to see if it’s an injector, switch the injector with another cylinder and see if the miss follows the injector. If not, then there are other reasons why that particular cylinder is not firing. That is the Old School way of finding a miss.
Written by Bruce C. Mallinson, Pittsburgh Power Inc., 3600 S. Noah Drive Saxonburg, PA 16056. Email: email@example.com. Phone 724-360-4080.