How to Tell if My Diesel Truck Engine Is Running Properly

Are you driving a truck in California and wondering if your diesel engine is in good shape?

You may have heard a few diesel truck engine tips here and there, but you’re confused about what it all means. Have you considered taking your truck in for a service?

While you might roll in and let the technicians do their job, giving them some clues could save you cash. In one survey, 23% of respondents felt like they had been sold unnecessary parts or service. The more you can help your technician narrow down the problem, the more money you will save on parts and labor. 

If your engine isn’t running as smooth as butter, it’s time to pay attention to the warning signs. Are you prepared to let a problem with your engine escalate into a complete failure?

We’re going to run through what to look and listen out for, so you know when it’s time to schedule a service. Read on! 

Strange Behavior

When you’re out in your truck, be alert to anything out-of-the-ordinary. One such change could be with your oil consumption. If you find you are constantly topping it up lately, this should trigger alarm bells.

Investigate your parking space for signs of an oily leak. If the ground is clear, take a look around the engine too. If the engine looks completely dry, then there might be a compression issue. 

You should always be listening out for odd diesel truck engine noises. Don’t begin to accept them as normal and switch your ears off to them – they’re telling you something important.

If you hear knocking, the liner seals may be damaged. It could also be a sign of wear to the main bearing or piston skirt. In older engines, clunking might indicate wear to the main/rod bearing. Pinging signals leaking injectors while tapping points to a valve clearance issue.

While idling, if the engine hunts up and down in intervals, it’s struggling to balance fuel and compression. If it’s just plain rough, several components might be at fault, such as leaking injectors, timing issues, or fuel pump degradation. An injector (or valve) that’s on the way out or has a clearance problem can cause an audible hesitation. 

Run-away is another bad sign. This happens when you turn off the engine, but it keeps on running. It’s often a sign that oil is leaking into the engine, which keeps the engine running in place of fuel.

Power Issues

Endless crank without a start often points to low compression. Diesel engines work by compressing only the air, increasing air temperature inside the cylinder. Atomized diesel fuel is then injected into the combustion chamber and spontaneously ignites.

Components that have degraded cannot create the correct pressure in the combustion chamber. Common culprits are cylinder walls, liners, valves, pistons, and rings. Hot and cold weather aggravates starting issues if these parts are failing.

Burning oil is never good and can lead to further problems, such as carbon deposits on the valves and combustion chamber. If it enters the chamber itself, these deposits can form on top of the pistons too. The flow of air to the cylinder will also drop, as will power and performance.

If your diesel truck engine struggles to gain speed compared to its glory days, this power loss could also be attributed to low compression. The turbocharger may even wobble through wear, causing oil to sneak into the intake. This immediately results in our next warning sign.

Smoke Signals

Excessive smoke often follows from poor diesel truck engine maintenance. While a small amount of blow-by is normal, large amounts of smoke hint at worn cylinder walls, pistons, or rings. This, in turn, causes exhaust to enter the crankcase.

You may also see considerable oil underneath the transmission or carriage because the exhaust smoke can carry it. 

If you notice your fuel consumption/spending ramping up, the injectors or rings might be shot. This needs addressing quickly because a surplus of diesel in the chamber can spiral into a negative chain of misfortune.

Unbalanced combustion can send excess fuel airborne as black smoke. If the underlying problem isn’t rectified, complete engine failure can soon result. 

If the smoke is blue, this is usually an indicator of oil burn, and this is likely a fuel system or engine problem. Ask your technician for a compression test, so you can see if you have to get that diesel engine overhauled or replaced.

Diagnosing the Problem

Is your diesel truck check engine light on? The great thing about modern engines is that they allow scan tools to be connected so that a technician can get to the root of the problem.

While some scan tools can be purchased by drivers most can only be afforded by a technician. That said, an on-board diagnostic tool like the G2 Injector Diesel Tester can aid an effective repair and save money on unnecessary parts and labor costs. While a shop might replace all your injectors, this tool can identify only the faulty ones.

Our final tip is to always follow the manufacturer’s recommendations in regards to your oil, especially the frequency that it should be changed. You also need to use the type of oil that they list because engines are fussy. Using an incorrect oil could lead to air in the hydraulics foaming, resulting in misfires.

Service Your Diesel Truck Engine

We’ve shown that a modern diesel truck engine might be high-tech, but they’re still susceptible to long-term issues like older engines. Don’t waste money replacing parts you don’t need to. Keep alert to helpful pointers that can guide your technician straight to the culprit and save you money.

If you drive a diesel truck near Rocklin, CA, we can keep it running. We are diesel performance specialists offering truck repair services on small or medium-duty vehicles. Our experienced staff provides services for brakes, electrics, engine, transmission, and everything under the truck.

Contact us today to book an appointment.

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