Comprehensive Guide for Installing an Oil Pressure Gauge on an LS-Derived Engine
What Type of Adapter is Needed for Installation?
To install an oil pressure gauge on an LS-derived engine, you will need specific adapters due to the metric ports on these engines. The factory ports on LS engines are typically M16x1.5 or M12x1.5, which do not match the standard 1/8″ NPT threads of most oil pressure senders. You will need an adapter to convert these metric threads to 1/8″ NPT.
Some of the recommended adapters include:
- AutoMeter Adapter #2268: This adapter threads into the M16x1.5 port on the back of the engine and provides a 1/8″ NPT port for the oil pressure sender.
- AutoMeter Adapter #2277: For the M12x1.5 port on the passenger’s side cylinder head, this adapter is used to get a proper 1/8″ NPT port.
Should I Use the Factory Oil Pressure Sender or a Separate Gauge Sender?
Compatibility and Modifications:
– Gen III Engines: For most Gen III LS engines, the factory oil pressure sender is not required for the ECU (Engine Control Unit) to function. The oil pressure signal is typically sent directly to the dashboard gauge or light.
– Gen IV and Special Cases: Some Gen IV engines and engines with Variable Valve Timing (VVT) or Displacement on Demand (DOD) might use the oil pressure signal for the PCM (Powertrain Control Module). However, for most LS swaps, the factory sender is not necessary for the ECU.
– Separate Gauge Sender: If you are installing an aftermarket oil pressure gauge, you will need a separate gauge sender. This sender should be compatible with your gauge type (mechanical or electric) and should match the thread type of the adapter you are using.
How Do I Tap the Engine Block for the Oil Pressure Gauge Sender?
Step-by-Step Instructions:
- Choose the Installation Location:
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You can use the factory port on the back of the engine or the passenger’s side cylinder head. Alternatively, you can drill and tap the cover plate above the oil filter for a precise reading.
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Tools and Materials Needed:
- Drill bit (5/16″)
- 1/8″ NPT pipe tap
- Teflon tape or sealant
- Socket wrench
- Ratchet and extension
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Safety glasses and gloves
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Drilling and Tapping:
- Remove the Cover Plate: If you choose to drill and tap the cover plate, remove it by unscrewing the two bolts holding it in place. The gasket is reusable.
- Drill the Blind Hole: Use a 5/16″ drill bit to drill through the blind hole in the cover plate.
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Tap the Hole: Use a 1/8″ NPT pipe tap to create the threads. Tap only halfway through to ensure the sender does not bottom out. Check the fitment of the sender as you tap to avoid over-tapping.
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Installation:
- Apply Sealant: Apply Teflon tape or sealant to the threads of the sender to ensure proper sealing.
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Install the Sender: Screw the oil pressure sender into the newly tapped hole. Ensure it threads in properly, leaving a couple of threads for tightening.
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Precautions:
- Avoid Over-Tapping: Do not tap the hole too deeply, as this can cause the sender to bottom out and potentially damage the threads.
- Clearance Issues: If you have stock exhaust manifolds, clearance might be an issue, and remote mounting of the sender may be necessary. Aftermarket headers usually provide enough space.