Diesel Engine Starting Problems - A Quick Reference Solutions Guide

Summary list of the most common causes and parts needed to fix them

The common problem is listed and the reference word or words for the part to fix it are listed as a solution.Using our website search box for both tech help and products, enter the words of the solution. This will take you directly to the resources we offer to help you fix the problem. We also list the difficulty. Level 1 indicates a beginner DIY job. Level 3 would indicate an intermediate DIY repair. Level 5 means you need professional mechanical experience to complete the job successfully.

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Problem & Solution

Common among these chassis:

W110 W111 W112 Sedan
W115
W116
W123
W124
W126
W140
W201

For Part 2 of the video please click HERE

USE OUR SEARCH BOX TO QUICKLY LOCATE YOUR SOLUTION: Enter key words listed below

1. Common Won’t Start Problems:  Battery goes dead - alternator not charging          

Solution: Voltage Regulator   

Difficulty Level: 1    

2. Common Won’t Start Problems:  Engine won’t turn over - bad starter motor

Solution: Starter motor

Difficulty Level: 2

3. Common Won’t Start Problems: Engine won’t turn over - failed neutral safety switch

Solution: Ignition switch easy install kit

Difficulty Level: 2

4. Common Won’t Start Problems: Engine won’t turn over - failed ignition switch

Solution: Ignition lock

Difficulty Level: 2

5. Common Won’t Start Problem: Engine won’t turn over - key won’t turn in ignition

Solution: Neutral safety switch

Difficulty Level:  3

6. Common Won’t Start Problem:  Engine won’t fire - no fuel flow

Solution: Fuel filters

Difficulty Level: 1

7. Common Won’t Start Problem: Engine won’t fire - air due to bad fuel lines / clamps

Solution: Fuel line replacement kit

Difficulty Level: 2

8. Common Won’t Start Problem: Engine won’t fire - burned out glow plugs

Solution: Glow plugs

Difficulty Level: 2/3

9. Common Won’t Start Problem:  Engine won’t fire - failed glow plug relay

Solution: Glow relay

Difficulty Level: 1

10. Common Won’t Start Problem: Engine won’t fire - old style tired glow system

Solution: Fast Glow Upgrade / Over ride

Difficulty Level: 2

11. Common Won’t Start Problem: Engine won’t fire - poor compression

Solution: Compression tester

Difficulty Level: 2

12. Common Won’t Start Problem: Engine won’t fire - internal engine problems

Solution: Diesel Performance Tuning manual

Difficulty Level:  3

13. Common Won’t Start Problem: Engine won’ run - bad fuel

Solution: Change fuel / diesel purge

Difficulty Level: 1

14. Common Won’t Start Problem: Engine won’t run - air in fuel system

Solution: Fuel line replacement kit

Difficulty Level: 2

15. Common Won’t Start Problem: Engine won’t run - air in fuel system

Solution: Hand primer pump

Difficulty Level:  1

16. Common Won’t Start Problem:  Engine won’t run - weak glow plugs

Solution: Glow plug reamer

Difficulty Level:  2

17. Common Won’t Start Problem:  Engine won’t run - weak glow relay

Solution: Glow relay upgrade

Difficulty Level: 1

18. Common Won’t Start Problem:  Engine won’t run - weak lift pump

Solution: Engine driven lift pump

Difficulty Level: 2

19. Common Won’t Start Problem:  Engine won’t run - worn out fuel injector nozzles

Solution: Fuel Injectors

Difficulty Level:  2

20. Common Won’t Start Problem: Engine won’t run - worn out timing chain

Solution:Timing chain

Difficulty Level:  3

21. Common Won’t Start Problem: Engine won’t run - faulty injection pump

Solution: Diesel Injection Pump

Difficulty Level: 3

22. Common Won’t Start Problem: Engine won’t run - too cold outside

Solution: Factory block heater

Difficulty Level: 3

23. Common Won’t Start Problem: Engine won’t run - too cold outside

Solution: Block heater

Difficulty Level: 2

24. Common Won’t Start Problem: Engine won’t run - fuel tank screen plugged

Solution: Fuel Tank Screen

Difficulty Level: 1

25. Common Won’t Start Problem: Engine won’t run - gummed injection system

Solution: Diesel Purge

Difficulty Level: 1

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Note: Additional resource guides are listed to the right.