Diesel Auto Repair

Crawford’s Auto Repair offers diesel auto repair for customers and businesses from Chandler, Gilbert, and surrounding nearby areas.

Vehicles with diesel engines are similar to other vehicles in that they have most of the same systems. The major difference is that the internal combustion within a diesel engine is not produced by a spark as in regular-gasoline engines. The combustion is ignited by compression which requires slightly different timing, although it is still a 4-stroke cycle. It’s not called the “Otto” cycle after Nicolaus Otto; it’s called the “Diesel Cycle” after Rudolf Diesel, but it is a refinement of the Otto cycle. For more context see our service page on the Engine as well as Lesson 5 of our Beginner’s Guide online or download the free ebook.

Diesel cycle gif, copyright unknown. Fair use applies.

In a diesel engine the air and fuel are not taken into the cylinder at the same time to be mixed and ignited by a spark plug. There is no spark plug. The air is drawn in first by plunging action from the piston head and often by turbocharging, then as the piston goes back up it compresses the air which heats it. The fuel is injected at the peak of compression which results in combustion. The reason the very top image on this page can be recognized as a diesel engine is because it shows a more reinforced valve train where the fuel is injected.

A diesel engine generally has more power than regular gasoline vehicles, so they are commonly seen in pickups and heavy duty vehicles, although there are also cars with diesel engines. The interest in smaller vehicles with diesel engines often goes up and down with gas prices. Traditionally, if regular gasoline becomes more expensive than diesel, then more people become interested in diesel vehicles, although now it’s more common for them to consider hybrids or electric vehicles.

Since a diesel engine generally operates with higher power, it requires a higher-power battery to start the engine. That’s why you can’t jump start a diesel engine battery with a regular gasoline vehicle. Learn more about the Electrical System.

A diesel engine might have a glow plug which heats the air initially before starting the engine. This assists with the starting process of the engine before the engine can cycle by itself. If a diesel engine has a glow plug then it will likely also have a glow plug indicator light in the dashboard.

Diesel fuel is heavier than regular gasoline. This is required for the diesel cycle to work. If a diesel engine were ever accidentally filled with regular gasoline then you should not drive the vehicle. It’s best to have it towed to the shop and have the gasoline removed. Learn more about the Fuel System.

Burning a heavier fuel can result in higher emissions. For that reason diesel engine vehicles have additional parts in their exhaust system to reduce these emissions. These additional parts have dashboard warning lights that are described in more detail below. Diesel engines are often turbocharged because the exhaust of a diesel is more powerful (which drives the turbo), and redirecting air in the exhuast back into the engine helps reduce emissions. Learn more about Exhaust & Emissions and the Air Intake System.

In the case of heavy duty vehicles, a more complex drivetrain can also be seen with a diesel engine. Vehicles with diesel engines often have 4-wheel drive, larger gear parts and shafts to match the towing capability of the higher power engine. Pulling heavier loads can put a strain on the transmission. So diesel vehicles may also have dashboard warning lights that indicate when the driver should be easier on the vehicle. Learn more about the drive train, transmission and 4-wheel drive.

Three well-known diesel engine brands and manufacturers are Ford Power Stroke, Dodge Cummons & Chevy Duramax. The owner of Crawford’s Auto Repair, Brad Weiss, has extensive experience with diesel auto repair of all makes and models, and he’s a Ford Senior Master Technician.

Diesel Engine Maintenance

Like any other vehicle, a diesel engine vehicle needs regular maintenance, and the hallmark of that maintenance is an oil change. These should be performed according to the vehicle manufacturer’s maintenance schedule while considering the use of the vehicle and the environment. The hot AZ weather and heavy use of the vehicle can require that maintenance services should be more frequent. At Crawford’s Auto Repair we include a full works package with the oil change at no extra cost. This includes a test-drive of the vehicle and full visual inspection both under the hood and under the vehicle with it raised on hydraulic lifts. If any signs, leaks or warning lights are noted then further investigation and possible repairs could be needed.

The unique exhaust system of diesel engines requires Diesel Emissions Fluid, also called Diesel Exhaust Fluid (DEF). This is required in all Diesel Engines built after 2010. This fluid is sprayed into the exhaust system to neutralize NOx into harmless nitrogen and water. The fluid will need to be refilled about every 5,000 to 6,000 miles which lines up exactly with oil changes.

Although diesel engines do not have spark plugs, they can need a “tune-up”. While a tune-up is traditionally considered to be a spark plug replacement service, it’s more accurately a “combustion cycle optimization and timing” service. This means that diesel engines can need a diesel engine tune-up to adjust the timing of the combustion cycle. This is performed at the mileage recommended by the vehicle manufacturer.

Since diesel engines can be harder on the transmission, a transmission fluid service is also an important maintenance service. This is performed at the mileage recommended by the vehicle manufacturer.

Diesel Vehicle Dashboard Indicator Lights

Diesel engine vehicles have similar warning lights as any vehicle. Some of the more important lights include the engine temperature light, low oil pressure light, charging system light, brake light, low coolant level, check engine light, and other lights which may indicate the need for diesel auto repair. Some lights are simply indicators, which means they are indicating something is on or that something is working correctly. Others are warning lights which can have different levels of severity. If they are red they generally mean “pull over now” or “don’t start driving until this is fixed”, however that is not a universal rule as some lights can be red in one vehicle but orange or yellow in another. For a more complete description of all these lights see the Warning Light Guide. Below are some of the indicator lights that are unique or important to diesel engines.

Water in Fuel Indicator

The filter which helps remove water from the fuel needs to be changed. The filter system may be called the Diesel Fuel Conditioner Module by some manufacturers.

Differential Lock Indicators And Axle Lock Indicators (4WD Vehicles)

These lights should only be on when you engage a differential lock or axle lock. When you’re stuck in the mud or snow it’s used to help get out. If it is accidentally engaged while you’re driving on the normal street then your vehicle will buck and feel like it’s tearing itself apart. Pull over safely to the side of the road to disengage it.

Malfunction, Disabled & Service Symbols For 4WD And AWD

The addition of an exclamation point, wrench, cross out, “SERVICE” or “DISABLE” to the symbol indicates that the vehicle needs to be serviced for that particular function or part. Some of these may temporarily flash while using that function. It’s when they stay on that it needs servicing. The “AWD” light may be green which simply indicates the AWD is engaged.

Signs of Diesel Engine Failure

These signs are possible symptoms that you might have with a diesel engine vehicle but it is not comprehensive of every engine system. For additional signs see the service pages for each engine system.

• Engine under performing
• Engine misfiring
• Uneven idling or rough idling
• Smell of fuel
• Poor gas mileage
• Starting problems
• Blue smoke
• Increased oil consumption
• Abnormal engine noise
• Turbocharger failure
• Vehicle won’t start
• Engine doesn’t stop running even after you turn it off

Diesel Auto Repair

Diesel auto repair could be indicated if leaks, warning lights or warning signs are discovered either by you or by a technician performing maintenance inspections.

Repairs which could be unique to diesel engines are related to their unique parts. If there is an issue with the fuel injectors then you need fuel injector replacement. If there is turbocharger failure then you’d need turbocharger replacement. Any signs of leaks would require leak repair. The various parts of the exhaust system could need to be replaced or repaired including the diesel particulate filter or the AdBlue system.

Diesel engines could also share similar repairs as other vehicles which would be described in more detail for each vehicle system:

See also 4-Wheel Drive Services.

Fleet Diesel Services

Do you own a business with a fleet that consists in part or entirely of diesel engine vehicles? Crawford’s Auto Repair can service all road-worthy vehicles ranging from consumer to commercial class. This includes all cars, vans and trucks with Ford Power Stroke, Dodge Cummins, Chevy Duramax and other diesel engines. We can also service special electronics and hydraulics which might be part of the vehicle.

Learn more about Fleet Auto Services.

Why Choose Crawford’s For Diesel Auto Repair:

Crawford’s Auto has technicians with a lot of diesel engine experience, including the owner who worked in dealership settings repairing Ford, Cummins and Duramax diesel engines.

Crawford’s Auto Repair was established to be different from the rest of the auto repair industry. We don’t pay staff by commissions and we never try to sell unnecessary repairs. You can speak to the technician working on your vehicle at any time. Our highly-trained technicians will treat your vehicle like it belonged to our own mother. Call 480-201-0740 to schedule an appointment for diesel auto repair today.