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Detroit Diesl 371 Troubleshooting

Detroit Diesl 371 Troubleshooting

The chart below shows the most common questions asked by owners of Detroit Diesel® engines 3-71 natural 4 valves when trying to troubleshoot why their engines underperform.  It categorizes areas of possible malfunction, likely cause and recommended action to bring your new, rebuilt or used  Detroit Diesel® engine back to proper operation.  The chart will give you confidence when speaking with your Detroit Diesel® engine mechanic or ordering parts.  As a quick reference guide only, the chart must not be thought of as a substitute for the use of your Detroit Diesel® engine 3-71 natural 4 valveOwner's operating or service manual.
For your convinience in looking up parts and pricing, please click here. You can also call us at 1-888-433-4735 or 305-545-5588.   We also encourage you to do a Google search for Detroit Diesel forum or Detroit Diesel forum 3-71 where you may find information from other people that have had the same question you have about your diesel engine.




Engine will not startLack of air intake or restricted air intake
Broken blower shaft 
Worn out blower shaft 
Defective fuel pump 
Defective starter 
Discharged battery 
High exhaust back pressure 
Black smoke coming out of engineDefective injector 
Contaminated fuel 
Broken or worn cylinder parts 
Engine overloaded 
Faulty intercooler or aftercooler (for turbo engines only) 
White smoke coming out of engineBroken piston ring 
Incorrectly installed ring set 
Defective injector 
Fuel quality or grade 
Long idle periods 
Broken or bent push rod 
Injector or governor improperly adjusted 
Low engine oil pressureWater in engine oil pan 
Fuel in engine oil pan 
Defective oil cooler 
Engine overloaded 
Crankcase overfilled 
Low engine RPMImproperly working injector 
Governor calibration 
Hi engine RPMGovernor calibration 
Engine overheatingDefective fresh water pump 
Defective raw water pump (marine engines only) 
Defective thermostat or thermostat seal 
Clogged radiator or heat exchanger (marine engine only) 
Grey smoke coming out of engineLong idle periods 
Defective intercooler or aftercooler (for turbo engine only) 
Restricted air intake 
Defective injector 
Contaminated fuel 
Blower or turbocharger seals leaking 
Geartrain makes noisesLow oil level 
Engine driven accesories 
Damage main or rod bearing 

Need More Specific information? We offer Detroit Diesel 3-71 Manual


Detroit Diesel 3-71 Usefull Information 

The 371 Detroit Diesel is a relatively small but reliable engine. Finding parts can be difficult, but not with Diesel Pro. We have a huge selection of parts ready to be shipped virtually anywhere in the world. Our website is designed to offer multiple shipping options, including next-day air. We offer fast order processing, less than one business day, to get your parts to you faster than many other sources. We are fully equipped to ship internationally quickly and seamlessly as well, so if you have problems with a generator in the Yukon of Canada, or need to repair a boat in the Caribbean, we can get you what you need. Be sure to check out our cylinder kit, which is one of our best sellers for this engine, and will come with everything you will need for the overhaul, including rings, retainers and liners. Whatever you need, give us a call and we will be happy to get an order started for you. Try us today and you will see, Diesel Pro is a better way to buy parts online.

If you are unsure that this is your engine, locate the model and serial number stamped on the engine block. For this series, this number will start with a 3A, and be similar to 3A12345. Older models may have a marking that starts with 371, such as 371-12345 or a serial number that starts with a 3-, such as 3-12345.

This engine is also called the GM 371 in some uses.

General Specs, Information and Horsepower

Listed here are the 3-71 Detroit Diesel specs. Please note that torque is based on rated power at 85 degrees F, and horsepower is based on brake horsepower.

The Detroit Diesel 371 is a 3 cylinder engine with a total displacement of 213 cubic inches and has 4 main bearings.

Normal lubricating oil pressure is 30-60 PSI at 1200 RPM, 38-60 PSI at 1800 RPM and 40-60 PSI at 2000 RPM.

With N60 Injectors:

Horsepower (BHP): 66 at 1200 RPM, 84 at 1600 RPM, 97 at 2000 RPM.

Torque (LB FT): 287 at 1200 RPM, 277 at 1600 RPM, 252 at 2000 RPM.

With N70 Injectors:

Horsepower (BHP): 65 at 1200 RPM, 90 at 1600 RPM, 111 at 2000 RPM.

Torque (LB FT): 272 at 1200 RPM, 294 at 1600 RPM, 288 at 2000 RPM.

Other Popular Categories

If you need parts for any other motor, be sure to check out our other popular categories.

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