I am trying to figure out where the engine coolant sensor is located?

Left front of engine block near alternator its screwed into the head no specials tools just a deep socket. Here are the diagrams below to show you where the coolant temperature sensor is on both 6 and 8 cylinder engines. Check out the diagrams (Below). Please let us know what you find.

But you need more tools I assume you have to remove the alternator

Do you have the 4.2L or the 5.3L engine?Because i just caught you out 6 as the engine i thought you put 8 so thats the location i gave the sensor for.The trailblazer has a inline 6 or V8 engine.If you have a 6 cylinder is a inline 6.

hoe yo install coolant temperature sensor

ENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENT

REMOVAL PROCEDURE
NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1.Turn the engine OFF.
2.Disconnect the negative battery terminal. CAUTION: Refer to Battery Disconnect Caution in Service Precautions.
3.Drain coolant below the level of the ECT sensor. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System.
4.Disconnect the ECT sensor electrical connector (1).
5.Remove the drive belt and the generator.
6.Carefully remove the ECT sensor (1).

INSTALLATION PROCEDURE
NOTE:
*Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.
*Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.
1.If installing the original sensor or a new sensor without sealant, apply thread sealer P/N 12346004 or equivalent.
2.Install the ECT sensor. NOTE: Refer to Fastener Notice in Service Precautions. Tighten Tighten the ECT sensor to 16 N.m (12 lb ft) .
3.Connect the ECT electrical connector (1).
4.Install the generator and the drive belt.
5.Connect the negative battery terminal.
6.Refill the engine coolant. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System.

where is the coolant temp sensor located

Hello - bikerthug Here is the info you requested Hope this helps. If you would like to offer feedback on your experience with me/us - feel free to go into the blue "Give Feedback" area under ImpalaSS

ENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENT REMOVAL PROCEDURE NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system. Turn the engine OFF. Disconnect the negative battery terminal. CAUTION: Refer to Battery Disconnect Caution in Service Precautions. Drain coolant below the level of the ECT sensor. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System.

Disconnect the ECT sensor electrical connector (1). Remove the drive belt and the generator.

Carefully remove the ECT sensor (1). INSTALLATION PROCEDURE NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system. Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage. If installing the original sensor or a new sensor without sealant, apply thread sealer P/N 12346004 or equivalent.

Install the ECT sensor. NOTE: Refer to Fastener Notice in Service Precautions. Tighten Tighten the ECT sensor to 16 N.m (12 lb ft) .

Connect the ECT electrical connector (1). Install the generator and the drive belt. Connect the negative battery terminal. Refill the engine coolant. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System.

where is this coolant temp sensor located

front right engine block near the generator. see picture bellow.

where and how to change a coolent temp. sensor on my 03 trailblazer.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENT REMOVAL PROCEDURE NOTE: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system. 1.Turn the engine OFF. 2.Disconnect the negative battery terminal. CAUTION: Refer to Battery Disconnect Caution in Service Precautions. 3.Drain coolant below the level of the ECT sensor. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System. 4.Disconnect the ECT sensor electrical connector (1). 5.Remove the drive belt and the generator. 6.Carefully remove the ECT sensor (1). INSTALLATION PROCEDURE NOTE: *Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system. *Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage. 1.If installing the original sensor or a new sensor without sealant, apply thread sealer P/N 12346004 or equivalent. 2.Install the ECT sensor. NOTE: Refer to Fastener Notice in Service Precautions. Tighten Tighten the ECT sensor to 16 N.m (12 lb ft) . 3.Connect the ECT electrical connector (1). 4.Install the generator and the drive belt. 5.Connect the negative battery terminal. 6.Refill the engine coolant. Refer to Draining and Filling Cooling System (Body Vin Code 6)Draining and Filling Cooling System (Body Vin Code 3) in Cooling System.

my engine check light is on, and i took it to get a diagnostic test and they said the coolant sensor is defective. where on my vehichle is this sensor located?

(1) Engine Coolant Temperature (ECT) Sensor (2) Engine Harness (3) PCM C1 (4) PCM C2 (5) Powertrain Control Module (PCM) C3

Number 1 shows the connector for the sensor. You will find the sensor mounts to the engine just behind the alternator.

I replaced the engine which is an 2008-2009, but the head is for an 2002 4.2L. there are no ports for the water temperature sensor to go due to the change in design from Cheverolet. Is there another port i can use in the block for this sensor?

Good morning.

I attached a picture of the location of the coolant sensor for the 2002 for you to view. it needs to go there and cannot be relocated.

Roy

I know where the stock sensor location is. I do not think you understand the question. There is no threaded water temperature sensor ports on both my block or my head.

So Roy, do I drill and tap the 2008 block to put in that location? Or is there another passage on the block that can be used? There is a plug beside the thermostat to the right

I posted the picture for the 2002. is that what you installed?

If it is next to the thermostat, yes as that is the location of the sensor. make sure you use a pipe thread tap.

Roy

The block is an 2008 which was the year Chevrolet moved the sensor to the back of the head. But my head is an 2002 which does not have the port in the back of the head. But can i remove this plug and use it instead? The first picture is the 2008 motor the second is the old 2002 block.

Sorry first and third pictures are the 2002 block second is the 2008 block.

yes, remove that plug for the sensor.

Roy

Now I see the old sensor in the old block but the hex plug is what I am talking about here Roy. I know it is for water but it is okay to use it instead?

yes, it may not be the same size. if it is not, you may need to get a adapter sleeve to fit it.

Roy

Yeah, i was thinking reducer to the sensor size.

correct, any plumbing supply or Lowe's and Home Depot would have the adapter.

Roy

locate temp sensor on motor

engine coolant temp. (ECT) sensor is on left front of engine block, near the alternator.