Land Rover Engine Coolant Temperature Sensor O-Ring - Genuine Land Rover LR001996

Product Information

Land Rover Coolant Temperature Sensor diagram for LR2

The engine coolant temperature (ECT) sensor, or simply coolant temp sensor, plays a vital role in monitoring the engine's operating temperature and communicating this information to various vehicle systems. This sensor is located in the engine's coolant passage typically in the cylinder head or block. It works by varying its resistance based on the temperature: as the engine heats up, the resistance decreases, and as it cools down, the resistance increases. The ECT sensor sends this data to the ECU, which uses it for several critical functions, such as the air-fuel mixture, ignition timing, and control of the cooling fans and dashboard temperature gauge. There are many European applications where there is more than one coolant temp sensor, separating the signals used for engine ECU and other functions such as gauges and fans.

A faulty sensor might send incorrect temperature readings to the ECU, resulting in poor engine performance. The most common example is if the sensor incorrectly signals that the engine is colder than it is, the ECU will enrich the air-fuel mixture unnecessarily, leading to rough idling, poor fuel economy, or even black smoke from the exhaust due to unburnt fuel.

Conversely, if the sensor falsely indicates an engine overheating condition, the ECU might trigger warning lights, prematurely activate the cooling fans, or even cause the car to go into "limp mode," limiting engine power to prevent damage (however this is a rarer failure mode).

• Wrong Temp Readings: If the coolant temperature gauge is acting unpredictably, or reading consistently too high or too low, it may be either a coolant temperature sensor or a thermostat. Because of this, it’s common to replace both of these parts at the same time for the best probability of success while the cooling system is opened.
• Running too rich: If you have noticed the temperature gauge is low and the exhaust is black and sooty, the engine might be stuck in the warm-up loop due to a bad coolant temperature sensor even though the engine is at the proper operating temperature controlled by the thermostat.
• Non-linear or suspicious live data output: For vehicles equipped with OBDII, use a scan tool to monitor the exact temperatures being output from the sensor. As the car warms up the output should be smooth and linear. If there are dead spots or it acts suspiciously, you may need to replace the sensor.

About Genuine Land Rover

The same parts Land Rover used to build your vehicle are sold as replacement parts under the “Genuine Land Rover” brand. These are manufactured under Land Rover’s direction, guaranteeing top quality. As you’d expect, they also carry a premium price and are sold exclusively through the Land Rover dealership network.

Genuine Land Rover parts trace their origins back to the earliest days of the brand in 1948, when Rover engineers built the first Series I using robust, serviceable components designed for durability in harsh environments. Over the decades, Land Rover established partnerships with leading European suppliers to ensure consistent quality and performance. This tradition continues today, with Genuine Land Rover parts representing the official replacement components engineered to the same specifications as those used on the production line.

What many owners don’t realize is that Land Rover doesn’t manufacture most of these parts themselves. Instead, they design the components, contract trusted suppliers to produce them, and then verify the quality. Many of these suppliers have partnered with Land Rover for decades. In the industry, they’re known as OEMs (Original Equipment Manufacturers)—brands you probably recognize, including Lemforder, ZF, Sachs, Bosch, Valeo, Zimmermann, Siemens VDO, Corteco, and more. It’s not unusual to open a Genuine Land Rover box and find one of these brands inside—just re-badged with a Land Rover logo.

On our site, look for OE tags on product pages to quickly spot parts that come straight from the original manufacturers. Choosing these can save you a significant amount compared to buying them in Genuine packaging. For more details on how to identify OE and OEM parts, check out our OE Academy.