Category Archives: Symptom T/S

Coolant in Oil

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NOTE:  Appearance of oil will be brown and have a milky-like state. Oil may be above recommended level as well.

  1. Pressurize the cooling system. Does the system hold pressure?
    1. Yes, the system holds pressure; Go to step 7.
    2. No; the system leaks down; Go to step 2.
  1. Remove the oil pan. Pressurize the cooling system. Where is coolant leaking from?
    1. Between the piston and liner; Go to step 3.
    2. Between the liner and block; Go to step 4.
    3. From the gear train or an oil return passage; Go to step 5.
    4. No coolant leaks are found present; Go to step 7.
  1. Remove the cylinder head and inspect for a failed cylinder kit. Was a failed cylinder kit found?
    1. Yes; replace lower end bearing kit, make necessary repairs, flush cooling system, and change engine oil.
    2. No; Go to step 4.
  1. Remove the cylinder liner where the leak was found. Was damage found?
    1. Yes; replace lower end bearing kit, make necessary repairs, flush cooling system, and change engine oil.
    2. No; Go to step 7.
  1. Pressure test the Oil Cooler. Were leaks found?
    1. Yes, leaks are found. Replace lower end bearing kit, make necessary repairs, flush cooling system, and change engine oil.
    2. No, leaks are not found; Go to step 6.
  1. Remove the cylinder head and inspect the cylinder head gasket for torn or debonded grommets.
    1. If damage is found, replace lower end bearing kit, make necessary repairs, flush cooling system, and change engine oil.
    2. If no damage is found, Go to step 7.
  1. Is fault code SPN 100/FMI 1 Low Engine Oil Pressure present?
    1. Yes; Inspect the Main and Connecting Rod Bearings.
    2. No; troubleshooting complete.

Metal In The Fuel System – Three Filter Fuel System

Published / by Mechanic / 7 Comments on Metal In The Fuel System – Three Filter Fuel System


For lot of DD engines a common problem is unit hard to start/no start but the engine cranks. A common cause for this symptom is fuel contamination, specifically metal debris in the fuel system on high mileage units. This can be a costly repair if misdiagnosed, thorough diag and repair is to prevent progressive damage and future no start issues.


  1. Remove the fuel filters from the fuel filter module. Inspect the fuel filter an inside of the fuel filter module for metal debris.
  2. If metal debris is found, use a magnet and inspect the fuel filters and inside the fuel filter module for magnetic debris. If no magnetic debris is not found inspect the fuel tanks and repair accordingly.
  3. Remove the high pressure flange from the High Pressure Fuel Pump. Place a magnet on the high pressure on the fuel pump outlet port 1 and check for magnetic debris. If no magnetic debris was found, replace the fuel filters and inspect all OEM fuel lines and tank for source of contamination. hpfp1
  4. If magnetic debris is found at the high pressure outlet port, removed the PLV(pressure limiting valve) and replace valve. Afterward begin to clean out the system thoroughly and replace required parts to prevent further progressive damage.

Replace the following components:

  • High Pressure Fuel Pump
  • Fuel Filter Module
  • High Pressure Fuel Injector Lines
  • High Pressure Fuel Rail Feed Lines
  • Fuel Injectors
  • High Pressure Flange
  • All Fuel Filters(including OEM)

Clean the following components:

  • Low Pressure Lines
  • Low Pressure Flange
  • Doser Supply Line
  • Return Lines
  • Fuel Rail
  • Frame Mounted Fuel filter Assembly
  • OEM Supply and Return Lines
  • Fuel Tanks



DD Engines with Poor Acceleration and Throttle Response

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Driver may experience poor acceleration and throttle response on DD engines. Code SPN 2659/FMI 1 EGR Flow Target Error Diagnostic/Low Flow may be logged, but at times no codes may be logged at all.


This may be caused by plugged ports in the EGR Venturi Pipe. This slows down the response of the sensor but sometimes produces no codes because the unit is in Smoke Control, often for several seconds at a time. This will cause no throttle response or poor acceleration.


Clean the two Venturi ports and replace the Delta Pressure sensor.

Venturi Ports

Venturi Ports



DPF HC Absorption Codes

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During extended periods at idle speed or high idle, unburned fuel from the combustion
process slowly builds up in the Aftertreatment Device/One Box. This unburned fuel is also referred
to as hydrocarbon.
If too much hydrocarbon is allowed to accumulate in the ATD, the next drive cycle could result in
higher than normal internal ATD temperatures as the hydrocarbon burns off. This could
potentially cause a failure of the Diesel Particulate Filter (DPF).
The Auto-Elevate feature eliminates the hydrocarbon buildup from reaching critical levels by
automatically increasing engine RPM. This process results in a temporary increase of exhaust
temperatures that effectively burn off the hydrocarbons within the ATD.

if Auto-Elevate is NOT enabled, excessive idle time may result in:

  • 1037/15 DPF HC Absorption Warning
  • 1037/0 DPF HC Absorption Very High
  • 1037/16 DPF HC Absorption High
  • 3250/14 Abnormal DOC Temperature Rise 2


The parameter to enable/disable this feature is located in the ACM group
“PGR005_DPF,” and is called “Extended Idle Auto RPM Elevate.”

It is a programmable feature via DDDL. It is defaulted to “OFF”. With Auto-Elevate enabled and after a predetermined amount of idle time, the DDEC 10 ACM
(Aftertreatment Control Module) will automatically elevate engine speed to 1100 RPM for up to
20 minutes. This will raise exhaust temperatures and eliminate hydrocarbon buildup in the ATD. When the process is complete, the engine returns to idle speed and the timer for Auto-Elevate resets.



Detroit Diesel does NOT recommend activation of the Auto-Elevate feature for PTO driven units. The automatic engine speed ramp-up could result in unexpected PTO operation. This is a potentially dangerous situation which may create chance of injury/death.



Low Oil Pressure Codes

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For all DD13/15/16 engines EPA07/10 low oil pressure codes may appear but are not related to the low oil level or condition.


There are five o-rings related to the oil pick up tube assembly, these o-rings become brittle over time. Once these o-rings have become brittle they allow air to enter the engine oil system. This is experienced by high mileage units, typically 600k KM and higher.



Figure 1

Verify low oil pressure with a mechanical gauge or DDDL. Once verified you will need to replace the o-rings(fig.3). If any debris/metal is found in the engine oil, the rod bearings have to inspected for progressive damage.

Figure 2.

Figure 2.

In worst case situations you’ll need to inspect the rod bearings and replace the crankshaft if required. Bearings with heavy wear are indicators of crankshaft failure(fig.1). If the bearings looks like fig.2 then there is no need for further repair, just replace the rod & main bearings.

FAILED O RINGS #4 #5 #10

#4 #5 #10


  • EPA07 DD15/16 OIL SUCTION MANIFOLD EA4721800351(QTY1) ITEM#1
  • O-RING A4721870980(QTY2) ITEM#5
  • O-RING A4721870880(QTY2) ITEM#10




Aftertreament Harness Codes

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On new EPA10/GHG14 model DD13/15/16’s have had problems with the aftertreament harness rubbing along the one box and causing multiple codes.

List of codes:IMG_20150910_214247

  • 3361/1 DEF dosing valve circuit failed low
  • 3361/4 DEF dosing valve circuit failed high
  • 3361/5 DEF dosing valve circuit failed open
  • 3361/31 DEF dosing unit defect
  • 3597/3 Proportional valve bank 1 circuit failed high
  • 3597/4 Proportional valve bank 1 circuit failed low
  • 4334/3 DEF pressure sensor circuit failed high
  • 4334/4 DEF pressure sensor circuit failed low

Unit that set the following fault codes may be due to the aftertreament doser harness rubbing near the DEF doser injector.

If the fault codes are present inspect the doser harness. Inspect the harness and check the anti-abrasion sleeve has rubbed through, if the wires are not damaged just apply tape over and re-position the harness to prevent further rubbing. If the wires are damaged then the entire harness will have to replaced. P/N DDE 23539669 is a service kit that can applied to both repairs to ensure this problem will never happen again.