| Parameter | Details |
|---|---|
| Product Name | Engine Coolant Temperature (Water Temp) Sensor |
| Part Number | 4436537 |
| Compatible Brands | Hitachi |
| Compatible Excavator Models | ZX110, ZX120 |
| Compatible Engine | Hitachi / Isuzu engines (ZX110/ZX120 series) |
| Sensor Type | NTC Thermistor (Coolant Temperature) |
| Material | Brass / Stainless Steel + Rubber Seal |
| Packing | PP bag inside, carton box outside |
| Payment Terms | Western Union, L/C, T/T, MoneyGram, D/A, D/P |
| MOQ | Acceptable trial order (1 piece accepted) |
| Shipping Mode | Air/Sea/Express (FedEx, UPS, DHL, TNT, etc.) |
| Place of Origin | Guangdong, China |
| Brand Name | COGENG |
| Certification | ISO9001 |
| Stock Status | ✅ In Stock |
| Warranty | 6 Months |
| Supply Capacity | 500 PCS |
The COGENG 4436537 Water Temperature Sensor is a high-precision, direct OEM replacement sensor specifically designed for Hitachi ZX110 and ZX120 excavators. These popular compact-to-medium excavators are widely used in construction, landscaping, utility work, and demolition projects worldwide.
This sensor monitors engine coolant temperature—one of the most critical parameters for engine performance, fuel efficiency, and longevity. The sensor uses a Negative Temperature Coefficient (NTC) thermistor—as coolant temperature increases, electrical resistance decreases. The ECU (Engine Control Unit) sends a 5V reference voltage through the sensor and measures the return voltage to calculate precise coolant temperature.
Why Coolant Temperature Monitoring is Critical:
| Function | How Temperature Data is Used |
|---|---|
| Fuel Injection Timing | Adjusts timing based on engine temperature for optimal combustion |
| Cold Start Assistance | Enables glow plugs / intake heaters in cold weather |
| Cooling Fan Control | Engages the hydraulic or electric fan at high temperatures |
| Warning Systems | Triggers alarms and derates the engine if overheating occurs |
| Emissions Control | Optimizes combustion for reduced emissions |
| Dashboard Gauge | Displays accurate temperature to the operator |
| Engine Protection | Shuts down engine if critical temperature is exceeded |
Manufactured under ISO9001 certified processes, the COGENG 4436537 features a brass/stainless steel housing, premium rubber O-ring, and a precision thermistor element to ensure accurate readings across the full temperature range (-40°C to +150°C).
Why Choose COGENG 4436537?
Direct OEM Replacement: Plug-and-play for Hitachi ZX110 and ZX120.
High Accuracy: Precisely calibrated to Hitachi ECU specifications.
Durable Construction: Brass/stainless steel housing withstands vibration and corrosion.
Leak-Proof: Premium O-ring pre-installed.
In Stock: Ready for immediate shipment with fast shipping.
| Component | Quantity | Description |
|---|---|---|
| Water Temperature Sensor | 1 | Complete sensor assembly with pre-attached connector |
| Rubber O-ring / Sealing Ring | 1 | Pre-installed on threaded base |
| Protective Plastic Cap | 1 | For shipping protection only |
| Installation Quick Guide | 1 | Basic instructions |
Note: No additional hardware or sealant is required for installation.
How a Water Temperature Sensor Works:
| Condition | Temperature | Resistance (Typical) | Voltage Output (Typical) |
|---|---|---|---|
| Engine Off (Cold) | -40°C (-40°F) | ~100,000 Ω | ~4.8V |
| Cold Start | 0°C (32°F) | ~30,000 Ω | ~3.8V |
| Ambient / Warmup | 25°C (77°F) | ~10,000 Ω | ~2.8V |
| Normal Operating | 80°C (176°F) | ~2,000 Ω | ~1.5V |
| Overheat Warning | 100°C (212°F) | ~1,000 Ω | ~1.0V |
| Critical Overheat | 120°C (248°F) | ~500 Ω | ~0.5V |
NTC Thermistor Behavior:
Temperature ↑ → Resistance ↓ → Voltage ↓
Temperature ↓ → Resistance ↑ → Voltage ↑
This sensor is specifically designed for the following Hitachi ZX Series excavators:
| Model | Engine | Typical Year Range | Application |
|---|---|---|---|
| Hitachi ZX110 | Isuzu 4JJ1 / Hitachi | 2000–2010 | Compact excavator |
| Hitachi ZX120 | Isuzu 4JJ1 / Hitachi | 2000–2010 | Compact excavator |
Additional compatible models (verify before purchase):
| Model | Compatibility |
|---|---|
| Hitachi ZX110-3 | ✅ Compatible |
| Hitachi ZX110-5 | ⚠️ Check connector type |
| Hitachi ZX120-3 | ✅ Compatible |
| Hitachi ZX120-5 | ⚠️ Check connector type |
| Hitachi ZX130 | ⚠️ Similar – verify |
| Hitachi EX110 | ❌ Older model – different sensor |
| Hitachi EX120 | ❌ Older model – different sensor |
⚠️ Important: The ZX Series (ZX110, ZX120) uses this sensor. Older EX Series (EX110, EX120) use a different sensor design.
| Parameter | ZX110 | ZX120 |
|---|---|---|
| Engine | Isuzu 4JJ1 / Hitachi | Isuzu 4JJ1 / Hitachi |
| Displacement | 3.0L – 3.9L | 3.0L – 3.9L |
| Horsepower | 80–90 HP | 85–95 HP |
| Operating Weight | 10,000–11,500 kg | 11,500–13,000 kg |
| Electrical System | 12V or 24V | 12V or 24V |
Normal Coolant Temperature Ranges:
| Condition | Temperature | Action |
|---|---|---|
| Cold Start | 0-30°C (32-86°F) | Glow plugs active |
| Warmup | 30-70°C (86-158°F) | Normal operation |
| Normal Operating | 75-95°C (167-203°F) | Optimal fuel economy |
| High Temperature Warning | 100-105°C (212-221°F) | Check cooling system |
| Overheat / Derate | >105°C (>221°F) | Engine derates |
| Brand | Part Number | Notes |
|---|---|---|
| COGENG | 4436537 | Direct replacement |
| Hitachi (OEM) | 4436537 | Original equipment |
| Hitachi (alternate) | 4436538 | May differ |
| Isuzu (OEM) | 894120-1230 | Similar (verify) |
| Aftermarket | WT-4436537 | Similar |
Note: Always match your original sensor part number. 4436537 is the Hitachi OEM number for this sensor.
✅ Direct OEM replacement for:
Hitachi part number: 4436537
✅ Designed For:
Hitachi ZX110 excavator
Hitachi ZX120 excavator
Isuzu 4JJ1 engine family
✅ Electrical Specifications:
Connector: 2-pin (Deutsch / AMP – matches Hitachi)
Operating Voltage: 5V DC (reference from ECU)
Output: Variable resistance (NTC thermistor)
✅ Mechanical Specifications:
Thread Size: 1/8-27 NPT or M10x1
Hex Size: 17mm, 19mm, or 22mm
Sealing: Rubber O-ring (pre-installed)
⚠️ Before purchasing, please verify:
| Check Item | Why It's Important |
|---|---|
| Machine Model | ZX110 or ZX120 (not EX series) |
| Machine Serial Number | Helps confirm specific configuration |
| Old Part Number | 4436537 or confirm |
| Connector Type | 2-pin (photo recommended) |
| Thread Size | 1/8-27 NPT or M10x1 |
❌ NOT Compatible With:
Hitachi EX110, EX120 (older series – different sensor)
Hitachi ZX130 (verify)
Hitachi ZX110-5 / ZX120-5 (check connector type)
Non-Hitachi equipment (different ECU calibration)
Installation decomposition diagram
Tools Required:
| Tool | Purpose |
|---|---|
| 17mm, 19mm, or 22mm wrench / socket | Remove and install sensor |
| Torque wrench (recommended) | Achieve 15–25 Nm spec |
| Clean rag | Wipe coolant spills |
| Flashlight | Locate sensor |
| Coolant (recommended) | Top up if needed |
Installation Tips:
⚠️ Engine must be cool – hot coolant can cause severe burns.
🧹 Clean mounting surface – debris can prevent proper sealing.
💧 Apply coolant to O-ring – helps seating and prevents twisting.
🔧 Do NOT overtighten – brass housing can crack at >30 Nm.
🚫 Never use PTFE tape – can clog coolant passages.
🔌 Listen for "click" – confirms connector is fully seated.
🔍 Check for leaks after engine reaches operating temperature.
Q1: What are the symptoms of a failing water temperature sensor on a Hitachi ZX110/ZX120?
A: Common symptoms include:
Check Engine Light (CEL) with error codes.
Temperature gauge reads 0°C or pegged at maximum.
Engine derates (reduced power) due to incorrect ECU readings.
Hard starting in cold weather (no cold-start assist).
Cooling fan runs constantly or never runs.
Poor fuel economy.
Engine overheating without warning.
Q2: Is this a genuine Hitachi OEM part?
A: No. COGENG is an aftermarket manufacturer (ISO9001) . Our parts are built to OEM specifications, offering the same fit and function at a reduced cost.
Q3: Will this sensor fit my Hitachi ZX110?
A: Yes – the ZX110 is one of the primary compatible models.
Q4: Will this sensor fit my Hitachi ZX120?
A: Yes – the ZX120 is one of the primary compatible models.
Q5: Will this sensor fit my Hitachi ZX110-3?
A: Yes – the -3 series is compatible with this sensor.
Q6: Will this sensor fit my Hitachi EX120 (older model)?
A: No – the EX series uses a different sensor design. This sensor is for ZX Series only.
Q7: What is the correct torque for this sensor?
A: 15–25 Nm (11–18 ft-lbs) . Do not overtighten – the brass housing can crack.
Q8: Can I install this sensor myself?
A: Yes, with basic mechanical skills (15–20 minutes). If unsure, professional installation is recommended.
Q9: Is this sensor in stock for immediate shipping?
A: Yes – COGENG maintains stock of 500+ units. Orders ship within 24–48 hours.
Q10: How long does shipping take?
A:
Express (DHL/FedEx/UPS/TNT): 3–7 business days worldwide.
Air freight: 7–12 days.
Sea freight: 20–40 days.
Q11: How do I place a trial order?
A: Contact your COGENG distributor. MOQ is 1 piece.
Q12: What is the warranty?
A: COGENG provides a 6-month warranty against manufacturing defects.
| Code | Description | Likely Issue |
|---|---|---|
| 110-03 | Engine Coolant Temp Sensor – Voltage High | Sensor open circuit / disconnected |
| 110-04 | Engine Coolant Temp Sensor – Voltage Low | Sensor shorted / internal failure |
| 110-08 | Engine Coolant Temp Sensor – Abnormal Frequency | Wiring interference / poor connection |
| PID 110 | Coolant Temperature – Out of Range | Sensor reading unrealistic |
If codes persist after sensor replacement, check the wiring harness for damage.
| Parameter | Value |
|---|---|
| Sensor Type | NTC Thermistor |
| Temperature Range | -40°C to +150°C |
| Resistance @ 25°C (77°F) | ~10,000 Ω |
| Resistance @ 80°C (176°F) | ~2,000 Ω |
| Resistance @ 100°C (212°F) | ~1,000 Ω |
| Connector Type | 2-pin Deutsch / AMP |
| Thread Size | 1/8-27 NPT or M10x1 |
| Hex Size | 17mm / 19mm / 22mm |
| Housing Material | Brass / Stainless Steel |
| Seal Material | Nitrile rubber (NBR) |
| Operating Voltage | 5V DC (from ECU) |
| Response Time | <5 seconds |
| ISO Standard | ISO9001:2015 |
| Country of Origin | China (Guangdong) |
| HS Code | 90259000 |
| Weight | Approx. 40g |
| Condition | Temperature | Gauge Reading | Action |
|---|---|---|---|
| Cold Start | 0-30°C (32-86°F) | Cold | Glow plugs active |
| Warmup | 30-70°C (86-158°F) | Rising | Normal |
| Normal Operating | 75-95°C (167-203°F) | Mid-range | Normal |
| High Temp Warning | 100-105°C (212-221°F) | Red zone | Check cooling system |
| Overheat / Derate | >105°C (>221°F) | Red zone | Engine derates |
To ensure we ship the correct sensor, please provide:
Machine Model: ZX110 or ZX120
Machine Serial Number: (helps confirm configuration)
Old Part Number: 4436537 (or confirm)
Photo of Old Sensor: (recommended – helps identify connector and thread type)
✅ In Stock – Ready to Ship.
✅ MOQ 1 piece accepted for trial orders.
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