COGENG 128-8945 1288945 342-2924 3422924 Water Temperature Sensor 325C 325D 325D

Decompose Pictures (Text Description)
    [ELECTRICAL CONNECTOR]  ← 2-pin Deutsch (matches CAT ECM)
            │
    [LOCKING TAB]           ← Audible "click" when connected
            │
    [BRASS / STEEL HOUSING] ← Hexagonal shape for wrench tightening
            │
    [INTERNAL THERMISTOR]   ← NTC (Negative Temperature Coefficient) element
            │
    [SENSING TIP]           ← Extends into coolant stream
            │
    [RUBBER O-RING]         ← Pre-installed, prevents coolant leaks
            │
    [THREADED BASE]         ← 1/8-27 NPT (most common)

How a Water Temperature Sensor Works:

NTC Thermistor Behavior:

• Temperature ↑ → Resistance ↓ → Voltage ↓

• Temperature ↓ → Resistance ↑ → Voltage ↑

COMPATIBLE MODELS & PART NUMBER GUIDE

Additional Compatible Models (Verify Before Purchase):

⚠️ Important: The 342-2924 and 128-8945 are often used interchangeably. The difference is typically the connector type or manufacturing revision. Both fit the same applications.

COMPATIBILITY NOTES

✅ Direct OEM replacement for:

• CAT Part Number: 342-2924 / 3422924

• CAT Part Number: 128-8945 / 1288945

✅ Designed For:

• CAT 325C (C9 engine)

• CAT 325D / 325D L (C7 / C7.1 engine)

• CAT 385C (C13 / C15 engine)

• CAT 330 / 330B / 330B L (3066 engine)

• CAT W330B (3066 engine)

✅ Engine Compatibility:

• CAT 3066 (6.6L, 6-cylinder)

• CAT C9 (9.3L, 6-cylinder, ACERT)

• CAT C13 (12.5L, 6-cylinder, ACERT)

✅ Electrical Specifications:

• Connector: 2-pin Deutsch (standard)

• Operating Voltage: 5V DC (reference from ECM)

• Output: Variable resistance (NTC thermistor)

✅ Mechanical Specifications:

• Thread Size: 1/8-27 NPT (most common)

• Hex Size: 17mm, 19mm, or 22mm

• Sealing: Rubber O-ring (pre-installed)

⚠️ Before purchasing, please verify:

❌ NOT Compatible With:

• CAT 325B (different sensor design)

• CAT 320B / 320C with 3066 engine (check connector)

• CAT C15 engine (different sensor calibration)

• Non-CAT equipment (different ECM calibration)

Installation Decomposition Diagram

Step-by-Step Installation – 15 Minutes or Less:

┌─────────────────────────────────────────────────────────────────┐
│  STEP 1: SAFETY FIRST                                           │
│  └── Turn off engine and allow to cool (coolant is HOT)        │
│  └── Disconnect batteries (negative first)                     │
│  └── Wear safety glasses – coolant can spray                   │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│  STEP 2: LOCATE OLD SENSOR                                      │
│  └── Thermostat housing (typically)                            │
│  └── Cylinder head (near water outlet)                         │
│  └── Follow upper radiator hose to engine block                │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│  STEP 3: REMOVE OLD SENSOR                                      │
│  └── Disconnect electrical connector (press locking tab)       │
│  └── Use appropriate wrench (17mm, 19mm, or 22mm)              │
│  └── Turn counter-clockwise – have rag ready for coolant drip  │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│  STEP 4: INSTALL NEW COGENG SENSOR                              │
│  └── Check rubber O-ring is in place (pre-installed)           │
│  └── Apply clean coolant or sealant to O-ring                  │
│  └── Hand-tighten into port                                     │
│  └── Torque to 15–25 Nm (11–18 ft-lbs) – DO NOT OVERTIGHTEN   │
│  └── Reconnect electrical connector (click = secure)           │
└─────────────────────────────────────────────────────────────────┘
                              ↓
┌─────────────────────────────────────────────────────────────────┐
│  STEP 5: TEST & VERIFY                                          │
│  └── Reconnect batteries                                       │
│  └── Refill coolant (if drained)                               │
│  └── Start engine – check for leaks at sensor base             │
│  └── Check dashboard temperature gauge                         │
│  └── Use CAT ET to verify ECM temperature reading              │
│  └── Allow engine to warm up – gauge should rise smoothly      │
└─────────────────────────────────────────────────────────────────┘
Tools Required:

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.

Frequently Asked Questions

Q1: What is the difference between 342-2924 and 128-8945?
A: Both are water/coolant temperature sensors for CAT equipment. The difference is typically:

• 342-2924: Often the newer part number superseding 128-8945.

• 128-8945: Older part number – may have a slightly different connector or thread.
  Both are fully interchangeable for the listed models. We recommend matching your old sensor part number for absolute certainty.

Q2: What are the symptoms of a failing water temperature sensor?
A: Common symptoms include:

• Check Engine Light (CEL) with codes: 110-03, 110-04.

• Temperature gauge reads 0°C or pegged at maximum.

• Engine derates (reduced power) due to incorrect ECM readings.

• Hard starting in cold weather (no cold-start assist).

• Cooling fan runs constantly or never runs.

• Poor fuel economy.

• Engine overheating without warning.

Q3: Is this a genuine CAT 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.

Q4: Will this sensor fit my CAT 325D L?
A: Yes – the 325D L uses the same water temperature sensor as the standard 325D.

Q5: Will this sensor fit my CAT 385C?
A: Yes – the 385C with C13 engine uses this sensor.

Q6: Will this sensor fit my CAT 330B L with 3066 engine?
A: Yes – the 330B L with 3066 engine uses this sensor.

Q7: Will this sensor fit my CAT W330B wheel loader?
A: Yes – the W330B uses the same sensor as the 330B excavator.

Q8: Do I need to drain the coolant to replace this sensor?
A: No – the sensor is located high on the engine, so minimal coolant loss occurs. Have a rag ready for any drips.

Q9: Do I need CAT ET to install this sensor?
A: The sensor is plug-and-play, but we recommend using CAT ET to:

• Clear stored diagnostic codes.

• Verify the temperature reading after installation.

• Perform sensor calibration if required.

Q10: What is the correct torque for this sensor?
A: 15–25 Nm (11–18 ft-lbs) . Do not overtighten – the brass housing can crack.

Q11: Is this sensor in stock for immediate shipping?
A: Yes – COGENG maintains stock of 500+ units. Orders ship within 24–48 hours.

Q12: 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.

Q13: How do I place a trial order?
A: Contact your COGENG distributor. MOQ is 1 piece.

If codes persist after sensor replacement, check the wiring harness for damage.

Additional Parameters

CAT Engine Coolant Temperature Reference

Ordering Information

To ensure we ship the correct sensor, please provide:

1. Machine Model: (e.g., CAT 325D L, CAT 330B, CAT 385C, CAT W330B)

2. Engine Type: (3066, C9, or C13)

3. Old Part Number: (Check the stamp on the old sensor – 342-2924 or 128-8945)

4. Photo of Old Sensor: (Highly recommended – helps identify connector and thread type)

✅ In Stock – Ready to Ship.
✅ MOQ 1 piece accepted for trial orders.
📞 Contact COGENG supplier today to place your order!

*Shipping Details Delivery Return*
Sales Price:
The displayed price is for reference only. Please contact COGENG sales support for the exact price.
Shipping Method:
Sea, land, or air transport; the specific method is determined based on the nature of the shipment.
Estimated Delivery Time:
Based on the dispatch time from the logistics carrier; the displayed arrival time serves as the reference.
Contact information is provided at the bottom of the page.
Merchant Return Policy:
Products shipped are not eligible for return or exchange.

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