Frequent Diesel Engine Problems - autotransexchange.com

Read on to learn about some of the problems people encounter with diesel engines.

Diesel Won’t Start Problems

Air leaks – vacuum in fuel supply
Blocked fuel supply – filters
Cam – crank sensor
Diesel injector/s bad
Faulty pressure regulator – sensor
Flat batter – low cranking speed
Fuel contamination
Glow plugs or relay fault in glow plug
High pressure pump bad
Internal engine problems
Low compression
Low fuel pressure
Low pressure supply pump-faulty
Not enough fuel supply

Hard To Start Diesel Engine Problems

Air leaks – vacuum in fuel supply
Bad pressure regulator – sensor
Blocked fuel supply – filters
Cam – crank sensor
Diesel injector/s bad
Flat batter – low cranking speed
Fuel contamination
Glow plugs or relay fault in glow plug
High pressure pump bad
Internal engine problems
Low compression
Low fuel pressure
Low pressure supply pump bad
Not enough fuel supply

Diesel Runs rough at lower RPM Problems

Air leaks – vacuum in fuel supply
Air intake restriction
Bad pressure regulator – sensor
Blocked fuel supply – filters
Cam – crank sensor
Diesel injector/s bad
Fuel contamination
High pressure pump bad
Injector blow-by seat leaking
Injector wiring harness bad
Internal engine problems
Low fuel pressure
Low pressure supply pump bad
Not enough fuel supply

Lack Of Diesel Engine Power Problems

Air leaks – vacuum in fuel supply
Air intake restriction
Bad pressure regulator – sensor
Blocked fuel supply – filters
Diesel injector/s bad
EGR problems
Fuel contamination
High pressure pump bad
Injector blow-by seat leaking
Internal engine problems
Low fuel pressure
Low pressure supply pump bad
Not enough fuel supply
Turbo problems – waste gate

Diesel Engine Knocking or Pinging Problems

Blocked fuel supply – filters
Cam – crank sensor
Diesel injector/s bad
Fuel contamination
Injector blow-by seat leaking
Injector wiring harness bad

Black Smoke From Exhaust Problems

Air intake restriction
Cam – crank sensor
Diesel injector/s bad
EGR problems
High pressure pump bad
Injector blow-by seat leaking
Injector wiring harness bad
Low fuel pressure
Turbo problems – waste gate

White Smoke From Exhaust Problems

Cam – crank sensor
Diesel injector/s bad
EGR problems
Fuel contamination
Glow plugs or relay fault in glow plug
Injector wiring harness bad
Low compression
Low fuel pressure
Turbo problems – waste gate

Blue Smoke From Exhaust Problems

Internal engine problems
Turbo problems – waste gate

Air Leaks In Vacuum Supply

Air leaks allow air to enter the fuel system through connections, fuel lines, fuel system and primary filter. Most leaks are spotted between the engine lift pump and filter inlet. When the diesel engine is running correctly it creates a vacuum to pull fuel through the engines filter. When the filter clogs the vacuum will increase. This will lead to engine shutting down if it doesn’t have a self bleeding system. Use a vacuum gage to perform a test.

Low Compression

Low compression in your diesel engine will prevent heat from being produced to ignite fuel and causes hard starting. This is usually a problem with high mileage or older diesel vehicles. To troubleshoot whether low compression is the problem or not, perform a cold engine compression test. Engine compression should be around 20-35 bars or 300-500 psi. If compression is below these numbers it will start causing problems.

Low Fuel Pressure

Low fuel pressure is usually created by poor fuel supply to pump/injectors/rail or the injectors/rail are not holding fuel correctly in the system. A great way to diagnose low fuel pressure is to begin with the tank and make sure that enough fuel is available to the pump. Also make sure the pump is still delivering fuel. Loosen supply pump from rail to pump. Check you fuel delivery.

We offer a full range of auto transmission repair and replacement services from automatic transmission to manual transmission to the entire Phoenix Metro area.

*Disclaimer – This is not an actual quote. Your transmission repair or replacement cost could be different than the prices you see on this guide. The only way to get an actual estimate is by searching for transmission repair and replacement shops near you. Contact Automatic Transmission Exchange if you are in the Phoenix area and need transmission repair or replacement.