| Parameter | Details |
|---|---|
| Product Name | CAT Engine Oil Sensor / Oil Pressure Sensor |
| Part Number | 1259859 / 125-9859 |
| Model Number | For C7 / 3116 / 3126 |
| Material | Iron + Rubber |
| Packing | PP bag inside, carton box outside |
| Payment Terms | Western Union, L/C, T/T, MoneyGram, D/A, D/P |
| MOQ | Acceptable trial order |
| Shipping Mode | By air, by sea, by express (FedEx, UPS, DHL, TNT, etc.) |
| Place of Origin | Guangdong, China |
| Brand Name | COGENG |
| Certification | ISO9001 |
| Supply Capacity | 500 PCS |
The COGENG CAT Engine Oil Sensor (Part No. 1259859 / 125-9859) is a high-precision oil pressure monitoring component designed specifically for Caterpillar (CAT) engines, including the C7, 3116, and 3126 series. This sensor plays a critical role in engine management systems by continuously measuring engine oil pressure and sending real-time signals to the ECU (Engine Control Unit). Proper oil pressure ensures adequate lubrication of moving parts, reducing friction, heat, and wear.
This sensor is manufactured under ISO9001 certified processes, ensuring strict quality control and consistent performance. The use of iron and rubber materials provides both structural durability and effective sealing against oil leaks and environmental contaminants. Each unit undergoes rigorous testing to meet or exceed OEM specifications.
| Component Name | Quantity | Description |
|---|---|---|
| Oil Pressure Sensor Body | 1 | Iron casing with integrated pressure sensing element |
| Sealing Ring / Gasket | 1 | Rubber, prevents oil leakage at mounting point |
| Electrical Connector | 1 | 3-pin or 2-pin (depending on engine variant) |
| Mounting Thread Nut | 1 | Iron, pre-installed for easy installation |
| Protective Cap | 1 | Plastic (shipping protection only) |
Outer Shell (Iron) – Hexagonal shape for wrench tightening.
Internal Pressure Sensing Diaphragm – Responds to oil pressure changes.
Circuit Board – Converts pressure into electrical signals.
Rubber O-Ring – Seats between sensor base and engine block.
Electrical Pin Assembly – Transmits signal to wiring harness.
Although originally designed for CAT engines, this oil pressure sensor is also widely used in JCB excavators that are powered by CAT C7, 3116, or 3126 engines. Below is a list of compatible JCB machine models:
| JCB Excavator Model | Engine Used |
|---|---|
| JCB JS200 | CAT 3116 |
| JCB JS220 | CAT 3116 / 3126 |
| JCB JS240 | CAT 3126 |
| JCB JS260 | CAT C7 |
| JCB JS300 | CAT C7 |
| JCB JS330 | CAT 3126 |
| JCB JS370 | CAT C7 |
| JCB JS460 | CAT C7 |
Note: Compatibility depends on the specific engine installed. Always verify your engine model before purchasing.
✅ Direct fit for:
CAT C7 (on-highway and off-highway versions)
CAT 3116 (mechanical and electronic)
CAT 3126 (all variants)
✅ Also compatible with:
CAT 3126B, 3126E
CAT C7 ACERT (early models check connector type)
⚠️ Important checks before purchase:
Verify original part number matches 125-9859
Confirm connector type (2-pin or 3-pin)
Ensure thread size matches (usually 1/8-27 NPT or M10x1)
❌ Not compatible with:
CAT C9, C13, C15 (different pressure range/connector)
CAT 3208, 3406 (different thread size)
Tools required:
22mm or 24mm deep socket or wrench
Torque wrench (recommended)
Clean rag
Thread sealant (optional, not required due to rubber seal)
Installation Tips:
Do not overtighten – risk of thread damage or sensor cracking.
Always install with engine cool to avoid burns.
After installation, idle engine for 2 minutes, check for oil leaks around sensor base.
Q1: What are the symptoms of a failing oil pressure sensor?
A: Common signs include:
Oil pressure warning light stays on or flashes
Incorrect oil pressure reading on dashboard gauge
Intermittent engine stalling or rough idle
No oil pressure reading at all
Q2: Is this sensor a direct OEM replacement?
A: Yes, COGENG 125-9859 is manufactured to match OEM specifications for form, fit, and function. However, it is an aftermarket part, not an original CAT part.
Q3: Does this sensor come with a warranty?
A: Yes, COGENG provides a standard 6-month warranty against manufacturing defects. Please contact your seller for specific warranty terms.
Q4: Can I use this sensor on marine CAT engines?
A: Yes, as long as the engine model is C7, 3116, or 3126. Marine versions may have different corrosion protection requirements – consult your mechanic.
Q5: What is the pressure range of this sensor?
A: Typically 0–10 bar (0–150 PSI). Output signal is analog (0.5V to 4.5V or variable resistance depending on version).
Q6: How do I know if my engine needs a 2-pin or 3-pin sensor?
A: Check your old sensor connector.
2-pin: Ground + Signal
3-pin: Ground + Signal + 5V Reference (common on electronic engines)
Q7: Can I install this sensor myself?
A: Yes, with basic mechanical skills. However, if you are unsure, professional installation is recommended to avoid engine damage.
Q8: What is the shipping time for trial orders?
A: By express (DHL/FedEx): 3–7 days. By air: 7–12 days. By sea: 20–40 days. Stock is available for immediate dispatch.
Q9: Do you offer bulk discounts?
A: Yes, for orders above 50 pcs, please contact sales for a volume discount quote.
Q10: Is the rubber seal replaceable?
A: The rubber O-ring is integrated into the design. If damaged, we recommend replacing the entire sensor to ensure proper sealing.
| Parameter | Value |
|---|---|
| Thread Size | 1/8-27 NPT or M10x1 (confirm before order) |
| Operating Voltage | 5V DC (regulated) or 12V/24V (depending on system) |
| Output Signal | Analog (0.5–4.5V) or Variable Resistance (0–250Ω) |
| Pressure Range | 0–150 PSI (0–10 bar) |
| Operating Temp | -40°C to +125°C |
| Sealing Type | Rubber O-ring (integrated) |
| Housing Material | Zinc-plated iron |
| Connector Type | Deutsch or Packard (confirm with seller) |
| Accuracy | ±2% at mid-range, ±3% at extremes |
| Response Time | <10 ms |
| ISO Standard | ISO9001:2015 |
| Country of Manufacture | China (Guangdong) |
| HS Code | 90262090 (pressure measuring instruments) |
For pricing, sample requests, or technical support, please contact your COGENG distributor or supplier. Provide your engine serial number and old part number to ensure correct fitment.
Recommended for:
Heavy equipment repair shops
Fleet maintenance
Individual machine owners
Contact COGENG
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