2007–2009 Saturn Aura Repair Manual

• Coverage in this file: 2007 Saturn Aura XR page headers with the 2.4L inline 4-cylinder engine, RPO LAT, VIN 5. This PDF is the 2007 engine-mechanical section; it does not contain separate 2008 or 2009 engine-mechanical sections.
• Covers major on-vehicle repair procedures including timing-chain and tensioner service, intake and exhaust camshaft/lifter work, camshaft actuators, cylinder-head replacement, oil-pan service, piston/connecting-rod and bearing replacement, cylinder-sleeve replacement, and complete engine replacement.
• Provides full off-vehicle overhaul coverage for block disassembly, cylinder honing, crankshaft and bearing inspection, piston/rod disassembly and assembly, cylinder-head disassembly and assembly, oil-pump service, thread repair, balance-shaft timing, final engine assembly, and engine pre-lubrication.
• Diagnostic content includes base-engine misfire and internal-noise symptom tables, compression and cylinder-leakage testing, oil-consumption and oil-pressure diagnosis, oil-leak checks, crankcase-ventilation diagnosis, and drive-belt noise, wear, tracking, and tensioner diagnosis.
• Includes reference data for fastener tightening, engine mechanical specifications, bearing and bushing clearances, piston-ring and cylinder inspection limits, valve and spring data, lubrication specifications, engine identification, and threaded-hole repair dimensions.
• Contains 582 numbered figures ranging from disassembled component views and timing/alignment illustrations to fastener-sequence diagrams, inspection views, lubrication cutaways, and special-tool setups, plus a dedicated illustrated Special Tools section.

Engine Mechanical Architecture

The engine description goes well beyond a basic specifications sheet. It identifies the aluminum inline-four block with pressed-in iron cylinder liners and a bedplate-style upper/lower crankcase, then explains the crankshaft, connecting rods and pistons, dual balance shafts, cylinder head, valve train, camshaft drive, manifolds, and lubrication circuit. The balance shafts share a roller-chain drive with the water pump, while the camshaft drive uses its own chain, guides, hydraulic tensioner, and camshaft position actuators.

The lubrication section traces pressurized oil through the crankshaft, connecting rods, balance shafts, camshaft bearing surfaces, hydraulic lash adjusters, and timing-chain tensioner. It also identifies the gerotor oil pump in the front cover and the cartridge-style filter arrangement. Because the overhaul chapters require precision measuring equipment, an approved engine stand, lifting equipment, and multiple dedicated service tools, this manual is best suited to professional technicians and experienced engine rebuilders rather than beginners.

Diagnostic and Specification Highlights

The diagnostic section starts with strategy-based engine-mechanical diagnosis and then breaks faults down by symptom. Coverage includes misfire with and without internal engine noise, upper- and lower-engine noise, no-crank conditions caused by a non-rotating crankshaft, coolant entering the combustion chamber or engine oil, compression and leakage testing, oil consumption, oil pressure, oil leakage, crankcase ventilation, and accessory-drive belt problems.

Specification tables support those procedures with bore and stroke data, compression ratio, cylinder condition limits, crankshaft and connecting-rod bearing clearances, piston-ring end gaps, valve stem-to-guide clearances, camshaft measurements, lubrication data, and component-specific torque/angle requirements. Valve specifications distinguish stem-to-guide clearance from the other valve, guide, seat, and spring measurements used during cylinder-head inspection.

Repair Depth, Illustrations, and Special Tools

The repair coverage is split into on-vehicle and off-vehicle work. On-car sections cover items such as the front cover, crankshaft seals, timing system, camshafts and actuators, valve stem seals and springs, cylinder head, oil pan, pistons and rods, flywheel, cylinder sleeves, and engine removal/replacement. The overhaul portion continues through cleaning, inspection, measurement, honing, thread repair, reassembly, timing, manifold installation, and engine pre-lubrication before startup.

Representative figures include Cylinder Head and Components, Engine Block and Components, Timing Chain and Components, Identifying Proper Exhaust/Intake Camshaft Alignment Positions, Cylinder Head Bolt Tightening Sequence, and Cutaway View of Lubrication System. The illustrated tool list identifies equipment such as EN 45680-850 for cylinder-sleeve removal/installation, J 8087 cylinder bore gage, J 35667-A cylinder-head leakdown tester, J 44217 timing-chain retention tool, J 43650 balance-shaft bearing remover/installer, and J 45299 engine pre-luber.

The manual also flags repair traps that matter during internal work. Improper handling of the timing-chain tensioner piston can activate the tensioner and require it to be reset, while incorrect cylinder-sleeve tooling, alignment, or lubrication can damage the block or installation equipment. Engine removal and overhaul work should be performed with suitable lifting/support equipment and the safety precautions specified for the operation.

This is an engine-mechanical repair PDF, not a complete vehicle service manual. Procedures that belong to other vehicle systems are cross-referenced rather than reproduced as full transmission, electrical, brake, HVAC, or body chapters.