Key Features and Benefits
- Billet aluminum construction: Precision-machined for durability and secure mounting.
- Two interchangeable center bolts: Includes M20×1.5 and 3/4-16 UNF thread configurations.
- Two 1/8 PT sensor ports: Designed for compatible aftermarket oil-pressure and oil-temperature senders.
- Additional M12×1.25 port: Provides another sensor mounting option using a washer-style seal.
- Dual sealing sizes: Includes 56mm and 65mm O-ring configurations.
- Sandwich-style installation: Fits between the engine block or filter housing and the original oil filter.
- Universal application: Designed for a variety of Japanese performance engines with compatible filter mounting dimensions.
- Retains factory filter location: Does not require relocating the oil filter or installing remote oil lines.
- Supports performance monitoring: Helps enthusiasts install gauges for oil pressure and oil temperature.
GReddy 12002801 Product Specifications
| Specification | Details |
|---|---|
| Manufacturer | GReddy / TRUST |
| Manufacturer part number | 12002801 |
| Product name | Universal Oil Filter Block Sensor Adapter |
| Product category | Oil filter sandwich adapter / gauge sensor adapter |
| Material | Billet aluminum |
| Engine-side center bolt option 1 | M20×1.5 |
| Engine-side center bolt option 2 | 3/4-16 UNF |
| Sensor ports | Two 1/8 PT |
| Additional sensor port | One M12×1.25 |
| O-ring sizes | 56mm and 65mm |
| Mounting location | Between engine oil filter mounting surface and oil filter |
| Oil-pressure sensor included | No |
| Oil-temperature sensor included | No |
| Oil filter included | No |
| External oil cooler included | No |
| Application | Universal, dimensional compatibility required |
Why Oil Pressure Monitoring Matters
Oil pressure is one of the most important indicators of engine lubrication health.
Your engine depends on pressurized oil to lubricate crankshaft bearings, connecting rods, camshafts, timing components, and other moving parts.
Turbocharged engines also rely on consistent oil delivery to protect the turbocharger’s bearing assembly.
When oil pressure drops unexpectedly, serious damage can occur quickly.
Installing an aftermarket oil-pressure gauge gives drivers a way to monitor pressure during cold starts, warm idle, acceleration, and sustained engine operation.
Our Oil Pressure Warning Light Diagnosis Guide explains why low oil pressure can indicate problems involving the oil pump, oil pickup, engine bearings, or lubrication system leaks.
The GReddy 12002801 makes it easier to add a compatible oil-pressure sender without modifying the engine block itself.
Why Oil Temperature Is Just as Important
Oil pressure tells you about the lubrication system’s operating pressure, but oil temperature provides another important piece of information.
As engine oil heats up, its viscosity generally decreases.
During extended track sessions, high-load driving, or turbocharged operation, oil temperatures can rise significantly.
An aftermarket oil-temperature gauge can help drivers identify when the lubrication system is operating outside the desired temperature range.
The GReddy 12002801 provides a dedicated location for a compatible oil-temperature sender.
Monitoring both pressure and temperature helps drivers understand how their engine behaves under different conditions.
Three Sensor Ports for Flexible Gauge Installation
One of the biggest advantages of the GReddy 12002801 is its combination of three sensor mounting ports.
| Sensor port | Quantity | Intended use |
|---|---|---|
| 1/8 PT | 2 | Compatible oil-pressure or oil-temperature sensors |
| M12×1.25 | 1 | Compatible washer-seal sensor or fitting |
This configuration allows builders to select sensor positions based on available clearance and the physical dimensions of their senders.
For example, a larger oil-pressure sender may require a different mounting position than a compact oil-temperature probe.
Always confirm that the sensor body clears the engine block, exhaust components, and surrounding accessories.
Unused ports must be sealed with the correct manufacturer-specified plugs and sealing method.
1/8 PT vs. 1/8 NPT: Don’t Make This Installation Mistake
The GReddy 12002801 uses 1/8 PT sensor ports, also identified as Japanese/BSPT tapered pipe threads.
These are not the same as 1/8 NPT threads commonly found on some American aftermarket gauge sensors.
Although the two thread types appear similar, their thread geometry and pitch differ.
Attempting to force an NPT sensor into a PT/BSPT port can damage the adapter and create an oil leak.
Before purchasing your gauges, verify the sender thread specifications.
If your sender uses 1/8 NPT, choose a properly rated conversion adapter rather than attempting to install it directly.
For additional guidance, our How to Wire Aftermarket Gauges Right article covers correct sensor selection, wiring, grounding, and the installation mistakes that can cause inaccurate readings.
What Vehicles Fit the GReddy 12002801?
The GReddy 12002801 is a universal oil filter sandwich adapter rather than a vehicle-specific direct-fit component.
It is designed to accommodate common Japanese oil filter mounting threads, but fitment depends on more than thread size.
Required Compatibility Checks
| Fitment requirement | What to verify |
|---|---|
| Oil filter mounting thread | M20×1.5 or 3/4-16 UNF |
| Sealing surface | Compatible with the supplied 56mm or 65mm sealing configuration |
| Oil filter clearance | Sufficient room for the added adapter thickness |
| Engine accessories | No interference with brackets, mounts, belts, or nearby components |
| Exhaust clearance | Adequate distance from manifolds, headers, and turbochargers |
| Sensor clearance | Enough room for senders, fittings, and wiring |
| Oil filter compatibility | Correct thread, sealing surface, and engine filtration requirements |
GReddy describes this adapter as suitable for many Japanese gasoline engines, including compatible Toyota, Nissan, Mazda, and Mitsubishi applications.
However, a matching oil filter thread does not guarantee fitment.
For Pro Street Online’s year/make/model database, list this product as Universal Fitment – Verification Required rather than assigning every vehicle that uses an M20 or 3/4-inch oil filter thread.
GReddy Oil Filter Sandwich Adapter vs. Oil Filter Relocation Kit
An oil filter sandwich adapter and an oil filter relocation kit serve different purposes.
The GReddy 12002801 is designed primarily to provide sensor mounting locations while keeping the original oil filter position.
A remote oil filter relocation kit moves the oil filter to another location using an engine-side adapter, oil lines, and a remote filter mount.
| Feature | GReddy 12002801 | Remote oil filter relocation kit |
|---|---|---|
| Adds oil-pressure sensor ports | Yes | Depends on kit |
| Adds oil-temperature sensor ports | Yes | Depends on kit |
| Retains engine-mounted oil filter | Yes | No |
| Requires remote oil hoses | No | Yes |
| Includes oil cooler connections | No | Depends on kit |
| Installation complexity | Generally lower | Generally higher |
| Universal fitment | Requires verification | Requires verification |
If your primary goal is installing oil-pressure and oil-temperature gauges, the GReddy 12002801 is a more direct solution than relocating the entire oil filter assembly.
Installation Guide: What to Know Before You Start
Installing a sandwich-style oil filter adapter is generally straightforward, but correct sealing and clearance are critical.
Step 1: Verify Fitment
Confirm the engine’s oil filter mounting thread and sealing surface dimensions.
Select the correct GReddy center bolt and sealing arrangement.
Step 2: Remove the Factory Oil Filter
Allow the engine to cool and follow the vehicle manufacturer’s oil service procedure.
Remove the oil filter and inspect the original mounting surface.
Make sure the previous filter gasket has been completely removed.
Step 3: Install the GReddy Adapter
Position the adapter with the appropriate O-ring and center bolt.
Follow GReddy’s installation instructions for orientation, sealing, and tightening.
Avoid improvised gasket arrangements or excessive tightening.
Step 4: Install the Gauge Sensors
Install compatible oil-pressure and oil-temperature senders in the appropriate ports.
Use the sealing method specified for each thread and sensor.
Do not substitute NPT fittings for PT/BSPT fittings.
Step 5: Route Sensor Wiring
Keep the wiring away from exhaust components, moving engine parts, and sharp edges.
Our Aftermarket Gauge Wiring Guide explains how to protect signal wires and avoid common grounding problems.
Step 6: Reinstall the Oil Filter
Use an oil filter compatible with the engine and selected adapter configuration.
Check that the filter clears all surrounding components.
Step 7: Check for Leaks and Verify Readings
After installation, confirm the engine oil level and inspect the adapter and filter sealing surfaces.
Follow the appropriate oil system priming procedure if required.
Start the engine only when the system is ready, verify that oil pressure develops normally, and shut it down immediately if pressure is absent or a significant leak appears.
Recheck the oil level and inspect the installation after the first heat cycle.
Frequently Asked Questions
What does GReddy 12002801 do?
It creates mounting locations for aftermarket oil-pressure and oil-temperature sensors between the engine and oil filter.
Does it fit M20×1.5 oil filter threads?
Yes. GReddy includes an M20×1.5 center bolt configuration.
Does it fit 3/4-16 UNF oil filter threads?
Yes. A 3/4-16 UNF center bolt configuration is also included.
How many sensor ports does it have?
Three: two 1/8 PT ports and one M12×1.25 port.
Can I install 1/8 NPT sensors?
Not directly. The 1/8 PT ports require compatible PT/BSPT fittings or properly specified adapters.
Does it include oil-pressure and oil-temperature sensors?
No. Sensors and gauges are sold separately.
Does it relocate the oil filter?
No. The original oil filter remains mounted at the engine.
Does it include an oil cooler?
No. This is a gauge sensor adapter, not an external oil cooler kit.
Will it fit my Honda, Toyota, Nissan, Mazda, or Mitsubishi?
It may fit compatible applications, but the filter thread, sealing surface, clearance, and sensor positioning must be checked before ordering.
Will this adapter increase horsepower?
No. It is a monitoring accessory that supports the installation of oil-pressure and oil-temperature gauges.
Upgrade Your Engine Monitoring With GReddy
The GReddy 12002801 Universal Oil Filter Block Adapter provides a practical way to add oil-pressure and oil-temperature monitoring to a compatible performance engine.
With billet aluminum construction, interchangeable M20×1.5 and 3/4-16 UNF center bolts, two sealing configurations, and three sensor ports, it offers flexibility for a wide range of custom gauge installations.
Whether you’re maintaining a modified street car or preparing a track-focused build, accurate engine monitoring is an important part of protecting your investment.
Choose the GReddy 12002801 when you need a genuine oil filter sandwich adapter for compatible 1/8 PT oil-pressure and oil-temperature sensors.
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