In 2019, freight trucks moved 11.84 billion tons of product, keeping everything from food to toilet paper on store shelves from one coast to the other. That sort of driving means a lot of wear and tear for truck engines. Replacing an engine is possible, especially with new and more fuel-efficient models releasing every year. However, engine replacement isn’t always an option, as the cost can be prohibitive. That’s where overhauls come in. What are some of the signs that your engine is due for an overhaul?
1. Poor Fuel Economy
One of the biggest indicators that an engine is in need of a tune-up or an overhaul is its fuel economy. Commercial trucks are necessarily known for great fuel economy, averaging 10.8 miles per gallon in Class 8 trucks, though it can range widely depending on whether the truck has to frequently travel uphill or can stay on relatively flat land. If your route terrain hasn’t changed and a truck is suddenly requiring more trips to the pump, it’s a good indicator something is going wrong that needs to be addressed.
2. Starting Problems
Diesel engines rely on compression to ignite the fuel and glow plugs to keep the fuel at the proper temperature when the engine is off. If there is a problem with these systems, hard starts or even failures could leave you stranded in the most inopportune places. These problems will generally begin to manifest as the occasional hard start before progressively getting worse.
A good cooling system works to keep the engines at a moderate operating temperature. When that begins to fail, it doesn’t take long for the engine to overheat. Add the fact that modern engines are often equipped with sensors that cause the engine to shut off automatically when overheating, and you could find yourself stranded. Keep an eye on the engine temperature and make a note when it starts creeping up.
4. Voltage Issues
It’s not just the internal components of the engine that need addressing. If the alternator fails or one of the batteries begins presenting a bad cell or fails a load test, the truck isn’t going anywhere. In tractor-trailers, this is an even larger problem because the electrical system has to support all of the driver’s creature comforts, such as the air conditioner in the cabin, while the engine is off.
5. Changes in Exhaust Color
The color of an engine’s exhaust can tell a lot of different stories and indicate a number of problems that could necessitate an overhaul. Diesel engines already emit a darker exhaust than gasoline ones in many cases. Blue exhaust could mean that there is too much oil in the engine, or it could mean that the internal components like the piston rings and valves are worn out and in need of replacement.
6. Poor Acceleration
When you put your foot on the accelerator, the vehicle should pick up speed the same way every single time. Slight variations are to be expected, especially when considering how the weight of a trailer can impact the vehicle, but generally it should always be very similar. If you press the accelerator and find the truck is struggling to accelerate and fighting for every mile per hour, the truck could use an overhaul.
Explaining Engine Overhauls
These engines see thousands of miles on the highway during their lifetimes. What goes into overhauling them and making them as close to new as possible?
Your typical overhaul starts with a complete or near-complete teardown of the engine. The goal here isn’t to replace everything, but to replace or rebuild the pieces that experience the most wear. This can include (but isn’t limited to):
- Cylinder heads
Anything that has the potential to wear out over time can and should be replaced. Things like the engine block usually don’t need anything more than good cleaning and re-lubricating unless there is severe damage that needs to be addressed.
Keep Your Fleet Running Smoothly
An engine overhaul for a well-used truck may seem like an expensive proposition, but it can breathe new life into a truck without worrying about the cost of purchasing something new. If your trucks are exhibiting any of the signs we mentioned, the problems aren’t fixed by regular maintenance, and the mileage is climbing higher by the day, it might be time to consider scheduling an engine overhaul.
And if you decide it’s time for an entirely new flatbed truck or other vehicle, be sure to check out all the work trucks and vans available on the leading online marketplace, CommercialTruckTrader.com.
Evelyn Long is the editor-in-chief of Renovated, a construction and real estate resource. Her work on construction and equipment maintenance has been published by Facility Executive, Training Journal and other industry publications.