12 Signs Your Diesel Engine Needs an Overhaul
Diesel engines require regular maintenance and attention, as minor issues can quickly lead to costly damages. Luckily, an engine rebuild is an excellent way to fix many problems and costs a fraction of the cost of a replacement engine.
An overhaul involves disassembling the engine and carefully identifying any faulty components. Once everything has been replaced and cleaned, a professional will reassemble the engine. An overhaul can help improve the performance and power of your diesel engine. Regular maintenance also extends the life of your engine and makes it more cost-effective.
How do you know if your engine needs an overhaul? Below are 12 signs of diesel engine failure.
1. Oil Sludge
One of the telltale signs of engine problems is the buildup of oil sludge on the dipstick or filler cap. The thick mixture usually consists of:
1) Waste oil
2) Dirt
3) Coolant
The presence of oil sludge indicates that engine components are not fully lubricated. If you find black residue or deposits like this around your engine, it may be time for an overhaul. Oil sludge can affect your engine’s performance and cause several problems, from increased fuel consumption to loss of power.
2. Metal Shavings
If you find metal shavings anywhere in your engine oil, it could be due to a lack of lubrication and friction between two components.
If you do find metal shavings, it’s best to address them quickly. Oil can spread these chips quickly throughout the engine, causing damage and further issues to multiple components. This can result in damage that is more expensive than an overhaul.
3. Increased Oil or Coolant Consumption
If you notice an increase in oil or coolant consumption in your diesel engine, it could indicate a number of issues. Worn piston rings often cause this issue. If the piston rings are not in the correct position, they will not be able to prevent diesel fuel from leaking out of the engine crankcase. This fuel is not as lubricating as oil, so if it leaks, it can cause costly damage.
Other causes of increased oil or coolant consumption include:
– Oil leaks
– Cracked cylinder head
– Faulty O-rings
– Cracked cylinder gaskets
– Worn or defective cylinder liners
4. Excessive exhaust
One of the signs that a diesel engine needs an overhaul is excessive smoke. This problem can easily go unnoticed because not all operators see the exhaust coming from the engine while it is operating. Excessive exhaust fumes can mean a variety of things. If the smoke appears blue, your engine is burning oil and diesel fuel may not be flowing properly. If the smoke appears white, it could be a sign that coolant is getting into the engine.
5. Knocking Noises
If you hear a loud knocking noise under the hood of your car, it may be time to get your diesel engine overhauled. This noise is different from normal engine noises and should be addressed immediately.
A loud rattle usually indicates one of the following problems:
– Bad bearings
– Defective injectors
– Defective piston pins
– Compression problems
6. Loss of Compression
Compression loss is a condition that usually causes poor performance or loss of performance. If you have a fuel or coolant leak, it can contaminate the engine oil and cause high oil levels in the crankcase.
Compression Loss
This problem also usually indicates a leak elsewhere inside the engine. If your engine is leaking from a cylinder, it may be due to worn parts that need to be replaced. Loss of power and leaking cylinders mean it’s time for an overhaul.
7. Reaching Milestones
How often your engine needs an overhaul depends on a variety of factors, including damage to parts and reaching certain milestones. Depending on the manufacturer, certain models will require maintenance after a certain number of miles or periods of use.
More frequent overhauls may be required depending on the vehicle’s operating conditions and the volume of stop-and-go traffic.
8. Turned Connecting Rod Bearings
When connecting rod bearings spin, misalignment of the bearings causes damage to the connecting rod journals and the connecting rod that connects them. This can occur due to a lack of lubrication in the crankcase.
If a broken connecting rod moves in the engine, further damage can occur. If you have a spun bearing, it is best to rebuild the engine to avoid costly damage.
9. Valve Drop
Valve drop occurs when a valve head is bent or sheared off and falls into the cylinder. This drop can cause serious damage to the entire engine system. If a valve drop occurs, it may be necessary to replace one of the following engine parts:
– Piston
– Cylinder
– Valve
If dropped valves are not attended to, they may require a completely new engine. Overhauling your diesel engine can prevent valve drop from happening in the first place.
10. Turbocharger failure
New diesel engines are equipped with a turbine-powered device called a turbocharger, whose job is to compress the air in the engine’s cylinders. If there is a problem with the turbocharger, it may start to wobble. This behavior is particularly harmful because even the slightest wobble can cause serious damage to the engine. You’ll know your turbocharger is failing if you see thick black smoke. This smoke means that there is oil in the intake and it’s time for an overhaul.
11. Excessive Blow-by
Some blow-by is normal in diesel engines, but excessive blow-by is a sign that something is wrong with your vehicle. Problematic blow-by occurs when a diesel engine ignites too hard and the piston rings can’t contain it, which can lead to excessive power output due to increased combustion pressure. To find the cause of the problem, a professional should perform a compression test on your engine. Regularly servicing your semi-truck engine can help prevent problems that lead to excessive blow-by.
12. Heavy Spinning or Idle
- If your diesel vehicle is having trouble idling or stalling, it’s time for an engine overhaul.
- If your vehicle bounces when stopped, this movement is a sign of wear and tear.
- If your engine won’t stop when you turn it off, it could be an indication that oil has gotten into the combustion chamber. A spinning engine can be very dangerous, so the sooner you address this problem, the better.