Clear Analog Pointer

The traditional pointer makes temperature changes easy to recognize at a glance.

After installation, drivers can learn the normal needle position under different conditions, including:

• Highway driving
• Stop-and-go traffic
• Extended idling
• Towing
• Hot weather
• Steep climbs
• Marine operation

A rising pointer can provide early notice of low coolant, restricted radiator flow, cooling-fan failure, thermostat trouble or a failing water pump.

Yellow Nighttime Illumination

Yellow illumination improves dial visibility during nighttime operation.

The warm lighting complements many classic dashboards and traditional gauge layouts without looking overly modern. The lighting circuit operates on 12V DC and draws up to approximately 0.3 amps.

Compact 2-Inch 52mm Housing

The gauge measures approximately 2 inches, or 52mm, making it suitable for many universal:

• In-dash openings
• Under-dash panels
• Dashboard pods
• Marine instrument panels
• Custom gauge clusters

Measure the mounting opening and available rear clearance before modifying the dashboard.

1/2-Inch NPT Sensing Bulb

The mechanical sensing bulb installs through a 1/2-inch NPT fitting.

Verify that the intended coolant port or adapter uses a compatible tapered NPT thread. Vehicles may instead use:

• 1/8-inch NPT
• 1/4-inch NPT
• 3/8-inch NPT
• Metric straight threads
• BSP pipe threads

An appropriate adapter may be required. Similar-looking threads are not automatically compatible, because plumbing standards apparently needed their own version of regional warfare.

Sealed 1.8-Meter Capillary Tube

The sensing bulb connects permanently to the gauge through an approximately 1.8-meter—or six-foot—sealed capillary tube.

Despite some listings calling this a “wire,” it is not ordinary electrical cable.

Never:

• Cut the tube
• Shorten it
• Splice it
• Crush it
• Create sharp bends
• Twist the sensing bulb
• Route it against exhaust components

Damage to the sealed tube will permanently disable the gauge.

Product Specifications

• Brand: SREUOIL
• Manufacturer part number: RSC093A
• Gauge type: Mechanical water-temperature gauge
• Display type: Analog pointer
• Gauge diameter: 2 inches / 52mm
• Fahrenheit range: 110–265°F
• Celsius range: 40–130°C
• Illumination: Yellow
• Lighting voltage: 12V DC
• Maximum lighting current: Approximately 0.3A
• Sensor fitting: 1/2-inch NPT
• Capillary-tube length: 1.8 meters / approximately six feet
• Construction material: Aluminum
• Installation type: Universal mechanical
• Application: Compatible automotive and marine cooling systems

The brand and model information were verified against the matching SREUOIL product listing.

What’s Included

• One SREUOIL 52mm mechanical temperature gauge
• Attached sensing bulb
• Attached 1.8-meter sealed capillary tube
• 1/2-inch NPT mounting fitting
• Illumination wiring
• Installation components

Confirm the exact package contents against physical inventory before publishing.

Compatible Applications

The gauge can be installed in compatible 12V applications, including:

• Passenger cars
• Classic vehicles
• Pickup trucks
• Motorcycles
• RVs
• SUVs
• ATVs
• Tractors
• Boats
• Marine engines
• Caravans
• Custom equipment

“Universal” refers to the basic gauge design. Fitment still depends on the mounting opening, capillary-tube length and sender-port thread.

Why Choose a Mechanical Gauge?

Mechanical temperature gauges offer several practical advantages:

• Direct temperature measurement
• No sender-resistance mismatch
• Temperature display without electrical power
• Traditional analog appearance
• Straightforward operation
• Compatibility with older vehicles

The primary tradeoff is installation. The capillary tube cannot be disconnected from the gauge, so the entire sensing bulb and tube must be carefully routed through the vehicle.

Installation Notes

The sensing bulb must be installed where it remains in contact with circulating engine coolant.

Potential locations include:

• Cylinder head
• Intake manifold
• Thermostat housing
• Engine block
• Coolant outlet

Before installation:

1. Let the engine cool completely.
2. Disconnect the negative battery terminal.
3. Confirm the coolant port uses 1/2-inch NPT threads.
4. Plan the entire capillary-tube route.
5. Mount the gauge in a compatible 52mm opening.
6. Route the sensing bulb through a protected firewall opening.
7. Keep the tube away from exhaust components.
8. Avoid belts, pulleys and cooling fans.
9. Leave enough slack for engine movement.
10. Install the bulb using the proper fitting.
11. Connect the illumination to fused 12V power.
12. Bleed air from the cooling system.
13. Check the fitting for coolant leaks.
14. Test the gauge before driving.

Do not remove the factory electronic coolant sensor unless the vehicle manufacturer confirms it is safe. That sensor may control the cooling fans, fuel mixture, ignition timing and dashboard warnings.

If rising temperatures occur alongside corrosion, coolant loss or visible leakage, review our guide to the seven signs of a failing radiator.

Frequently Asked Questions

Is this a mechanical or electrical gauge?

It is a mechanical temperature gauge. The 12V connection powers only the yellow dial illumination.

What temperature range does it display?

The dial displays 110–265°F and 40–130°C.

Is the 1.8-meter line electrical wire?

No. It is a permanently sealed mechanical capillary tube connecting the sensing bulb to the gauge.

Can the capillary tube be shortened?

No. Cutting or modifying it will permanently damage the gauge.

What thread size does the fitting use?

The supplied fitting uses 1/2-inch NPT threads.

Does it fit every 12V vehicle?

No. The lighting is compatible with 12V systems, but installation also requires a suitable 52mm opening, enough routing length and a compatible coolant port.

Will the temperature reading work without electrical power?

Yes. The mechanical reading should operate without power, but the yellow illumination will not.

Does the gauge have an overheating alarm?

No alarm is specified. The operator must monitor the pointer.

Can I add an adapter?

A compatible adapter may be used if it securely holds the sensing bulb in circulating coolant without restricting flow or preventing proper insertion.

Can this be used on a boat?

It may be used in compatible marine cooling systems. Protect the gauge, lighting connections and capillary tube from corrosion, moisture and physical damage.

What should I do if the gauge reads hot?

Reduce engine load and pull over safely if the temperature continues rising. Shut the engine off if steam appears or coolant escapes. Never remove a radiator cap while the cooling system is hot.

Our guide on how to deal with an overheating engine explains the next diagnostic steps.

Simple Mechanical Coolant Monitoring

The SREUOIL mechanical water-temperature gauge offers direct analog monitoring in a compact 52mm package.

Its dual-scale dial, yellow illumination, 110–265°F range and six-foot capillary tube make it a practical option for compatible classic vehicles, trucks, boats and custom builds.