Next to the thermostat. you will see it when you remove the hose
If you mean for Coolant level sensor it is on the bottom of the plastic coolant dish on the passenger side of the car.
I have 1993 Volvo 960 and the coolant senor is located on the back of the block ( next to fire wall) The access is very difficult because the are two water hoses and some electrical wires right next to it.
In a 1993 Volvo 940, the block temperature sensor is typically located on the engine block, near the thermostat housing. It can be found on the driver's side of the engine, often near the cylinder head. This sensor monitors the engine's coolant temperature and sends the information to the gauge on the dashboard. If you're having trouble locating it, consult your vehicle's repair manual for a detailed diagram.
On a 1989 Volvo 740, the coolant temperature sensor is typically located on the engine block near the thermostat housing. It is usually positioned on the driver's side of the engine, close to the intake manifold, and may have a single or dual wire connector. To access it, you may need to remove any obstructing components, such as the air intake or engine cover.
To replace the engine coolant temperature sensor on a Volvo S70, first, ensure the engine is cool and disconnect the negative battery terminal. Locate the sensor, typically found near the thermostat housing or on the engine block, and unplug the electrical connector. Remove the old sensor using a socket or wrench, then install the new sensor, taking care to apply any necessary sealant. Reconnect the electrical connector and the battery terminal, and check for leaks after refilling coolant if necessary.
I'm not sure what you're asking, but if you mean that you are getting an OBD-II diagnostic code of P0128 from your Volvo S40, that code corresponds to a problem with coolant temperature. On a first generation Volvo s40 (99-04), this usually means that the thermostat or electronic coolant temperature sensor are malfuctioning or have failed.
To install the coolant sensor on a 1998 Volvo S70, first ensure the engine is cool and disconnect the battery. Locate the coolant temperature sensor, typically found near the thermostat housing on the engine block. Remove the electrical connector and unscrew the old sensor using a socket wrench. Install the new sensor by screwing it in place, reconnect the electrical connector, and then reattach the battery. Finally, check for leaks and ensure the coolant level is adequate.
Try looking on the EGR valve underneath the intake manifold.
in mirror
On the passenger side of the engine compartment there is a surge tank remove that and the sensor is in the bottom. It will be the clear plastic tank where you add Coolant.
If a complete tune-up (with new ignition wires, plugs, air filter, cap, rotor) does not improve gas mileage, replace the coolant temperature sensor. The sensor is located under the intake manifold. Cost is about $39.00. Check the shape of the wiring socket to make sure you get the right sensor.
It is located in the intake pipe between the MAF sensor and the throttle.