Genuine Mazda Piston Cooling Oil Jet / Spray Nozzle • LF01-10-590A

Genuine Mazda LF01-10-590A Piston Cooling Oil Jet / Spray Nozzle

Replacement Genuine Mazda piston cooling oil jet for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models with 1.8 L8-VE or 2.0 LF-VE MZR petrol engines.

The oil jet is installed in the cylinder block beneath the crankshaft and piston assembly. It receives pressurised oil from the engine lubrication system and directs a controlled spray towards the underside of the piston.

The oil flow helps remove heat from the piston crown while providing additional lubrication around the piston-pin and connecting-rod small-end area. Correct jet operation is particularly important during sustained engine speed and load.

The jet contains a small oil passage that can become restricted by sludge, debris or contaminated engine oil. A blocked, damaged or incorrectly installed jet may reduce piston cooling and local lubrication.

One oil jet is fitted for each piston. The four-cylinder MX-5 NC engine therefore uses four jets in total. This listing supplies one Genuine Mazda jet, so select a quantity of four when replacing the complete engine set.

• Part type: Piston cooling oil jet
• Common names: Piston oil spray nozzle / oil squirter
• Mazda catalogue description: Valve, Oil Jet
• Location: Cylinder block beneath each piston
• Function: Sprays pressurised engine oil onto the underside of the piston
• Additional function: Assists piston-pin and small-end lubrication
• Quantity per cylinder: 1
• Quantity fitted per engine: 4
• Quantity supplied: 1 oil jet
• Mounting hardware included: No additional hardware unless physically supplied
• Piston or connecting rod included: No
• Brand: Genuine Mazda
• Part No.: LF01-10-590A
• Earlier Mazda reference: LF01-10-590
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC 1.8 and 2.0 engines

Typical reasons for replacement:

• Complete engine rebuild
• Crankshaft or piston removal
• Oil jet blocked by sludge or debris
• Jet damaged during engine dismantling
• Restricted or irregular oil spray pattern
• Internal engine contamination or bearing failure
• Thread or nozzle damage
• Replacement cylinder block being assembled

Fitment advice: This oil jet is used in the original Mazda MX-5 NC 1.8 L8 and 2.0 LF MZR cylinder block. Confirm compatibility where an alternative block, engine conversion or modified lubrication system has been installed.

Other items to consider: Inspect all four oil jets, the cylinder-block oil galleries, crankshaft bearings, connecting rods, piston pins and piston undersides. Where an engine has suffered bearing damage or oil contamination, the complete lubrication system should be cleaned thoroughly before reassembly.

Useful tools / consumables: Suitable socket or installation tool, calibrated low-range torque wrench, compressed-air cleaning equipment, lint-free cloths, clean engine oil, engine assembly lubricant and suitable oil-gallery cleaning brushes.

Difficulty guide: DIY Difficulty: Specialist / Advanced. Significant lower-engine dismantling is required. The jet must be installed in the correct position and orientation without damaging its nozzle or restricting crankshaft and connecting-rod movement.

Why Genuine Mazda? Genuine Mazda oil jets are manufactured to match the original cylinder-block thread, nozzle position, oil-flow characteristics and spray direction. Correct geometry helps direct the intended oil supply towards the piston and piston-pin area.

What’s in the box: One Genuine Mazda piston cooling oil jet / spray nozzle, part number LF01-10-590A.

Installation notes: Remove and dismantle the engine in accordance with the applicable Mazda workshop procedure. Clean the oil gallery and mounting location thoroughly before installation. Confirm that the jet passage is clear and that the nozzle has not been bent or damaged. Start the jet by hand, install it in the correct orientation and tighten it to the applicable Mazda specification. Before completing the engine build, confirm adequate clearance from the crankshaft and connecting rod and verify that the lubrication passages are clean and unobstructed.