Code Details
| Display code | SPN 175 FMI 0 |
|---|---|
| SPN | 175 |
| FMI | 0 |
| OEM code | None listed |
| Manufacturer | PACCAR |
| System | Engine �?lubrication / cooling |
| Component | Oil cooler / coolant system / oil temperature sensor |
| Source address | Unknown or not applicable |
| Severity | high |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-12 |
Plain-English Meaning
The PACCAR MX-13 oil cooler uses engine coolant to maintain oil temperature in the normal operating range. SPN 175 FMI 0 means oil temperature exceeded the normal ceiling. On Kenworth T680, T880, Peterbilt 579, and other MX-13-equipped trucks, this is most commonly a cooling system issue �?degraded coolant, restricted radiator, or a fan clutch that is not engaging fully under load. On Kenworth T680, T880, and Peterbilt 579 trucks with the MX-13, engine oil temperature rises most rapidly when the oil cooler is restricted or bypassed, or when the EGR cooler is introducing additional heat into the oil circuit. DAVIE4 and PACCAR ESA display oil temperature in real time and record fault event snapshots. The MX-13 EGR cooler is a known wear item at high mileage, and a cracked EGR cooler allows coolant into the exhaust, which can also produce thermal anomalies in the aftertreatment system. Reviewing EGR cooler outlet temperature in DAVIE4 alongside oil temperature narrows the diagnosis.
SPN 175 FMI 0 is Engine Oil Temperature above normal operating range. DAVIE4 and PACCAR ESA both provide live engine oil temperature and coolant temperature data for the MX-13. Comparing these two temperatures in real time under load is the key diagnostic step �?a wide gap between oil temperature and coolant temperature (with oil higher than expected above coolant) points to the internal oil cooler, while both temperatures elevated together points to the external cooling system.
Common Symptoms
- Oil temperature warning on the instrument panel
- Possible engine power reduction from protection derate
- May occur in combination with elevated coolant temperature in hot weather or on grades
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Cooling system issue: low coolant, restricted radiator, or fan clutch not fully engaging
- Internal MX-13 oil cooler fouled with coolant scale
- Thermostat stuck partially closed
- Extended high-load operation in extreme ambient temperature
- Oil temperature sensor fault
First Checks
- Connect DAVIE4 or PACCAR ESA and monitor oil temperature and coolant temperature under load
- Inspect coolant level, color, and condition �?scale-laden coolant reduces oil cooler efficiency
- Check fan clutch operation �?DAVIE4 allows a fan clutch activation test
- Inspect the radiator for external restriction or internal flow blockage
- If coolant temp is normal but oil temp is high, suspect oil cooler fouling
- Monitor oil temperature and EGR cooler outlet temperature together in DAVIE4 under load
- Inspect the coolant reservoir for signs of oil contamination from an EGR cooler crack
Can I Keep Driving?
PACCAR MX-13 will derate to protect against oil temperature damage. Address promptly.
Related Codes
Related Lookup Pages
Sources
- PACCAR / Kenworth / Peterbilt Service Support — MX Engine Resources PACCAR Inc. · oem · accessed 2026-06-11 · confidence medium
Source: PACCAR Inc., PACCAR / Kenworth / Peterbilt Service Support — MX Engine Resources. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - PACCAR Engine Technical Services PACCAR Inc. · oem · accessed 2026-06-10 · confidence medium
Source: PACCAR Inc., PACCAR Engine Technical Services. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - SAE J1939 Standards Collection SAE International · official · accessed 2026-05-05 · confidence medium
Source: SAE International, SAE J1939 Standards Collection. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Does the PACCAR MX-13 oil cooler share coolant with the EGR cooler?
The MX-13 engine has both an EGR cooler and an oil cooler in the cooling circuit. If the coolant system is marginal �?low flow, scale buildup, or degraded coolant �?both the EGR cooler and oil cooler can be affected simultaneously. Checking for companion EGR temperature codes alongside SPN 175 FMI 0 helps identify whether the cooling system is generally stressed.
Is the oil temperature sensor on the PACCAR MX-13 located in the oil pan or the main gallery?
The MX-13 oil temperature sensor is located in the main oil gallery, not in the oil pan. This placement measures oil temperature as it circulates through the engine. DAVIE4 or PACCAR ESA can confirm the exact sensor location for the specific model year and engine serial number.
Does DAVIE4 show the oil temperature limit threshold for the PACCAR MX-13?
DAVIE4 displays live oil temperature data and fault event records. The specific oil temperature threshold for SPN 175 FMI 0 is calibration-specific and is contained in the engine calibration data accessible through DAVIE4 or PACCAR ESA with the appropriate access level.