Semi-truck Engine Overhauling: What You Need To Know

Whether you own or operate a semi-truck, most probably you can perform simple repairs yourself in the event of engine breakdowns. However, in extreme cases and repetitive malfunctions, expert technicians may have to eventually let you choose between buying a new truck and doing an engine overhaul. Knowing that your vehicle is your way of make a living, you might be eager to learn more about the latter option which is semi-truck engine overhauling.
But first, let us define semi-trucks.
What is a semi-truck?
Semi-trucks are vehicles composed of a powered truck and one or more semi-trailers. They are also commonly labelled as “semis”, “semi-trailers”, “semi-trailer trucks” or “semi-tractor trailers”. Other terms to refer to these types of trucks include “big rigs” and “18-wheelers”.
Why semi-truck?
The word “semi” just means to say that it is not completely one solid truck. Rather, a semi-truck is essentially half a tractor unit and half a semi-trailer. The semi-truck may have one or more semi-trailers attached to it to carry freight.
What is a semi-truck engine overhaul?
Simply stated, a typical overhaul means giving the engine a new life. It incorporates meticulous rebuilding and restoration.
The processes involved in an overhaul are disassembling, cleaning, inspecting and repairing the truck’s diesel engine as necessary. Moreover, the engine may also undergo some tests using factory-approved procedures.
Semi-truck engine overhauling may also include parts replacement like pistons/liners, piston rings, oil pumps, bearings, gaskets, seals and thermostats. Likewise, cylinder heads, injectors and the water pump may have to be replaced as well. Additionally, the turbocharger, camshaft, rocker arms, crankshaft, shaft and gears should also be thoroughly examined for wear.
Signs your semi-truck engine is ready for an overhaul
One main reason for an overhaul is engine failure. As mentioned earlier, effective engine wear monitoring may require shop tests. These procedures usually cover oil analysis and crankcase blow-by testing.
Oil analysis, to simply put, is the lab test done for engines as blood chemistry is for humans. It provides valuable and in-depth information regarding the engine’s present health condition. For crankcase testing, on the other hand, engine shops can evaluate for excessive blow-by.
But as an owner-operator, you should also be aware of the fundamental ways to detect engine problems. The slightest sight, touch, smell or sound can give you cues that something might be off with your semi’s engine.
Below are some of the indications that it might be a good time for you to consider getting your engine an overhaul.
Mileage of more than 1,000,000 kilometers
If your engine is constantly hauling heavy loads and is nearing the 1 million kilometers mark, then it might be the right time to initiate for an overhaul.
Foam on the dipstick
This means that there is water in the oil. Droplets of water that form on the dipstick cause it to develop rust. At times, it may also show as gunk on the neck or the fill cap.
The smell of burning oil
Of course, we all know that when something is burning, extreme heat is mainly the cause. Hence, the smell of burning oil is a sign of overheating engine oil.
Decreased oil viscosity and oil smelling like fuel
These usually indicate a high level of fuel dilution. To probe further, place a drop of oil on a small piece of cardboard. If it spreads quickly, then it is a sign of fuel.
Engine running roughly
If you notice any engine noise like pinging, immediately bring your rig to the shop for proper checking.
Exhaust emitting heavy or blue smoke
Irregularities in exhaust smoke are clear hints of engine issues.
Low cylinder compression
Antifreeze contamination of the oil usually causes worn pistons/liners, piston rings or valves. Subsequently, it may result in low compression in one or more cylinders. For accuracy, run a compression test on each cylinder.
Large metal particles lodged in filter pleats
To inspect the filter, you might need a technician to professionally do the procedure. If the oil filter test shows the presence of large particles, further lab analyses may be called for.
Ways to carry out a semi-truck engine overhaul

Find shops offering commercial engine overhaul services
You have the option of whether you want to avail of the services from a certified or non-certified shop. Certified shops offer top-of-the-line systems and parts and therefore can be a bit more costly. However, non-certified shops can pose potential risks as they are not governed by the same set of standards as certified shops and may potentially offer sub-par parts and service.
Whether you are based in Edmonton, Fort McMurray, Lloydminster, Red Deer or anywhere in Northern Alberta, you can count on Major Overhaul for reliable, tried and tested first-rate diesel engine rebuilds.
Obtain engine overhaul kits and do-it-yourself
For a more cost-effective solution, you may opt for a DIY option. Overhaul kits enable you to secure a similar system that shops use for their overhaul services.
However, this will only be possible if you are well-versed and comfortable working with engines, or you know someone who is. Ultimately, this is a convenient choice for truck owners who have comprehensive in-house resources.
How much does semi-truck engine overhauling costs?
It depends. The charge will adjust from case to case.
Depending on the severity of the engine issues, the number of parts to be replaced, the technician’s professional fee and other factors, the cost of an engine overhaul will always be a valuable amount.
But just to give you an idea, engine overhauls from certified facilities range anywhere from CA$26,500 to CA$53,000.
Although the cost of an overhaul may be significant, keep in mind that investing in a new engine or truck is far more expensive.
Ready for a semi engine overhaul in Edmonton?
Don’t settle for underperforming equipment! Considering an overhaul at the first signs of power or efficiency issues while the engine is still not extremely worn is a wise and cost-effective decision.
Regain your semi’s optimum performance and boost uptime! Schedule your semi-truck engine rebuild and restoration with Major Overhaul and call 780-468-1069 today.
Awesome post! Keep up the great work!
David, blog author: https://oilpeaks.com/
It was informative when you talked about how overhauling can give an engine new life. It seems like you would want to overhaul your engine every couple of years if you are someone that drives it on a daily basis. This seems like a good way to keep your vehicle on the road and help you be as productive as possible.