Engine Removal
Step-by-step guide to removing the Renesis 13B-MSP engine from the RX-8 (Series 1, 2004-2008). The engine is pulled out the top with the transmission staying in the car — the conventional RWD method, as opposed to the Mazda factory manual which drops the entire subframe from underneath.
Source: RotaryResurrection AGP — photo-documented procedure. Adapted with permission. Original PDF (RENESIS 13B-MSP Engine Removal)
:::tip Time Estimate Approximately 3 hours at a steady pace once you're familiar with the procedure. :::
Before You Begin
Tools Required
| Tool | Size / Type | Notes |
|---|---|---|
| Socket set | 10mm, 14mm, 17mm, 19mm, 21mm | Most commonly used sizes; use 6-point sockets to avoid rounding bolts |
| Gear wrench | 14mm | For A/C compressor top bolts |
| Breaker bar | 1/2" drive | For stubborn motor mount and cross-member bolts |
| Long extensions | Various | For reaching bolts from the wheel wells and engine bay top |
| U-joint socket adapter | For bell housing bolts from underneath | |
| Engine hoist (cherry picker) | 2-ton minimum | With chain and load leveler |
| Floor jack + jack stands (or car ramps) | Front of car ~15" off the ground; car ramps preferred for extra clearance | |
| Flat blade screwdriver | Thin blade | For oil cooler C-clips |
| Pliers / vice grips | For hose clamps and stuck hoses | |
| Pry bar | For separating engine from transmission | |
| Punch | For exhaust studs if they break | |
| Shop rags / towels | Oil spillage catch | |
| Penetrating lubricant | For rusty fasteners — spray and let sit overnight if possible | |
| Tape + marker | For labeling connectors | |
| Nylon lashing straps | For reaching the rear engine lifting point if chain hooks won't fit | |
| 15L drain container | Large enough for coolant drain |
Safety & Preparation
- Photograph everything before disconnecting — wiring, hose routing, connector positions
- Label every connector with numbered tape as you disconnect it
- Work on a cold (or lukewarm) engine to avoid burns
- Have drain pans ready for oil and coolant (~9L coolant, ~5.7L oil)
- Ensure you have enough space around the vehicle for the engine hoist
- Check ceiling clearance if working in a garage — you may need to lower the car on jacks to gain relative height for extraction
- Spray penetrating lubricant on rusty bolts the night before — especially exhaust fasteners and cross-member bolts
- Avoid using socket adapters (1/2" to 3/8") under heavy torque — they snap. Use proper 6-point sockets that match your breaker bar drive
This procedure is written for Series 1 (2004-2008 MY). Steps marked with * may differ slightly for Series II (2009-2012 MY).
:::warning Automatic Transmission Cars If your RX-8 has an automatic transmission, expect significantly more difficulty accessing the block drain bolt and oil cooler lines — the AT cooler lines leave almost no room. Consider skipping the block drain bolt and draining coolant only from the radiator. :::
Phase 1: Underhood Disconnection (Top Side)
1.1 — Hood, Battery & Air Intake
- Remove the hood (2 bolts each hinge + washer nozzle line)
- Remove the battery
- Remove the battery box and battery tray
- Remove the air filter box and base
1.2 — Air Pump & PCM
- Remove the air pump
- Remove the air pump support bracket (2 bolts) — provides extra clearance for engine extraction
- Remove the PCM lid
- Unplug the PCM* and remove it
- Remove the upper small coolant hoses going to the coolant reservoir tank from the tank; lay aside on the engine
:::danger Label Your Connectors Number (or mark) all coil wiring plugs (1 to 4) and injector wiring plugs before disconnecting. This saves hours of confusion during reinstallation. :::
1.3 — Engine Wiring Harness
:::tip Keep Harness Connected for Now If you need to crack the front crank pulley bolt (19mm), keep the wiring harness connected so you can still crank the engine with the starter. Use the starter bump trick: place a breaker bar on the crank bolt, brace it against the frame, then bump the starter — the engine rotation cracks the bolt loose instantly. Disconnect the harness only after this step. :::
- Locate the junction box on the driver's side of the engine bay — a black plastic box where the engine harness and chassis harness meet via 4-6 large multi-pin connectors
- Unplug all connectors* on the engine side of that junction box (these are the ones going toward the engine, not toward the firewall/fuse box)
- Lay the engine harness aside on top of the engine
- Unbolt the battery wiring harness from the chassis crossbar
- Unplug/unbolt the battery harness from the main fuse box
- Unplug the connectors holding the chassis harness to the engine harness above the radiator fans (the cross-connect cable to the fuse box and main battery cables up front — easy to forget)
- Pull the harness back and lay it on top of the engine out of the way
1.4 — Brake Booster Hose
- Remove the brake booster hose from the brake booster
- Lay it on top of the engine out of the way
1.5 — A/C Belt
- Remove the A/C belt
1.6 — Fuel Lines
- Disconnect both fuel lines by prying off the colored retaining clip and pulling the line up
- Note: One clip has a second small plastic retainer inside (burgundy color piece under the blue clip) — do not lose it
- Reinstall clips onto the lines immediately after removal so you remember their orientation
- Remember for reinstallation: Blue line = front, Red line = back
:::danger Never Cut the Fuel Line If a heater hose is stuck, you can cut it — it's replaceable. But never cut the fuel line. :::
1.7 — A/C Compressor (Top Bolts)
- Unplug the A/C compressor electrical connector from the top
- Lay it on the engine
- Remove the 2 top A/C compressor bolts (a gear wrench works best)
Phase 2: Front End Disconnection
2.1 — Oil Cooler Lines
- Disconnect the oil cooler lines*
- For dual-cooler models: there are 3 lines up front
- One comes from the engine and goes under the front crossbar
- The other 2 are under the driver's frame rail near the radiator
- The top line does not go to the engine but must be moved to access the bottom one
- Use a thin blade flat screwdriver to gently pry the retaining C-clip out (don't lose or bend it)
- Twist/pull the hose end off the metal pipe
- Be prepared to catch oil spillage with a towel
- Lay the 2 hoses from the engine facing up near the engine
:::tip Seized Oil Cooler Lines If the oil cooler line from the front cover is seized, it is easier to unbolt it from the front cover under the A/C compressor (accessible from under the car). Be ready with a shop rag — it's full of oil. Wedge it out of the way beside the steering shaft. :::
Phase 3: Raise Vehicle & Drain Fluids
- Jack the front of the car up and place it securely on jack stands ~15" off the ground (or use car ramps for better clearance and stability)
- Remove both front wheels
:::tip Car Ramps vs Jack Stands Car ramps provide significantly more under-car clearance than jack stands and are more stable. They make under-car work much easier for this job. :::
3.1 — Drain Coolant
- Drain the coolant at the radiator (petcock at bottom)
- Drain from the middle side iron housing (left side, just above oil pan)
3.2 — Drain Engine Oil
- Drain the engine oil
3.3 — Lubricate Exhaust Fasteners
- While fluids are draining, apply penetrating lubricant to the 3 exhaust fasteners holding the main catalytic converter onto the exhaust manifold header
Phase 4: Coolant & Vacuum Hoses (Underneath)
- Remove the lower 1" diameter coolant hose for the coolant reservoir tank from the engine; lay aside
- Remove the upper radiator hose from the engine (use lubricant on the outlet if the clamp won't slide)
- Tuck the hose out of the way
- Remove the heater core hose (right side)
- Remove the lower radiator hose
- Remove the ground wire on the passenger side of the lower intake manifold; lay it aside away from the engine
- Remove the left side heater core hose at the firewall pipe
:::tip Stuck Hoses If hoses are eroded/stuck to the fittings, use vice grips to clamp on and wiggle them free. If a heater hose is completely seized, it can be cut — but never cut the fuel line. :::
Phase 5 — Belts, Pullies & A/C Compressor (Bottom)
- Remove the alternator belt by releasing tension off the alternator
- Remove the crank pullies and trigger wheel by removing the 4x 10mm bolts
:::danger Do NOT Remove the E-Shaft Bolt Do NOT remove the 19mm e-shaft bolt. Only the 4x 10mm pulley bolts. The crank pullies must be removed to provide clearance for the engine to clear the crossbar in the engine bay. :::
- Remove both bottom bolts on the A/C compressor from underneath
- Let the A/C compressor lay down slightly on the steering gear (it stays in the car)
:::warning A/C Compressor Bolts Corrode The A/C compressor mounting bolts are prone to corrosion and breakage. Deal with them while the engine is still supported in the bay — extracting broken bolts from a loose engine on a stand is much harder. :::
Phase 6 — Motor Mounts & Cross-Member
- Remove the motor mount top retaining bolt (14mm) on each side of the car
- Remove the cross-member under the engine/transmission using 17mm and 19mm sockets
6.1 — Exhaust-to-Transmission Bracket
- Remove the small bracket joining the exhaust manifold and the transmission
6.2 — Starter
- Remove the starter*
- The top retaining bolt requires a wrench on the engine side and a socket to remove the nut from the back side
6.3 — Catalytic Converter
- Remove the 3 nuts holding the catalytic converter to the exhaust manifold header
:::tip Broken Exhaust Studs It is not uncommon for one or more studs to break, shear off, or strip. If this happens:
- Hammer the affected stud out backwards with a punch
- Use a replacement bolt and nut during installation
- The gasket/O-ring inside is often rotted — replace it whenever separated :::
Phase 7 — Motor Mount Bracket Removal & Engine Separation
7.1 — Lift Engine Slightly
- Attach the engine hoist and lift the engine about 1/2" to 1" — just enough to take pressure off the motor mounts
- The bracket has a lip on the bottom edge that prevents lifting more than this amount
- The goal is to have neither lip resting on the motor mount
:::tip Engine Support Methods If working without an engine hoist initially, you can support the engine with a cross-bar/Ram across the engine bay, plus bricks and hardwood blocks under the oil pan. The hoist takes over once you're ready to extract. :::
:::tip Factory Lifting Points The RX-8 has small metal lifting tabs — one on the front and one on the rear of the engine. The rear tab is very hard to reach with chain hooks; use nylon lashing straps instead. Keep chains as short as possible to maximize vertical clearance. :::
7.2 — Right Side Motor Mount
- Remove the right motor mount (use long extensions from the top of the engine bay — 14mm nut and 14mm bolt)
- Remove the right motor mount bracket from the engine (3x 17mm fasteners — easiest with a long extension from the wheel well)
7.3 — Left Side Motor Mount
- Push the engine toward the right side
- Unbolt the left motor mount bracket and remove it from the engine (tight fit but possible)
- If unable to remove the bracket, remove the left side motor mount itself for extra clearance
7.4 — Lower Engine for Bell Housing Access
- Lower the engine/transmission about 4 to 5 inches to gain access to the top of the bell housing
- Unplug the front oxygen sensor from the engine harness
- Remove the harness clip from the passenger side of the transmission
7.5 — Bell Housing Bolts (Top)
- Remove the upper 2 or 3 bell housing bolts (easier from underneath with a long extension and u-joint)
- The top driver's side bell housing bolt is behind the slave cylinder line — gently bend the line out of the way to access the bolt
7.6 — Rear Wiring Harness
- Disconnect the rear oxygen sensor and the other connectors on the top rear of the transmission
- Remove the clips holding this harness to the top of the transmission
- Pull the harness out through the top and lay it on the engine (part of the engine wiring harness)
Phase 8 — Engine Extraction
8.1 — Support Transmission
- Support the transmission with a jack and blocks
- Jack it slowly up all the way until the transmission begins to touch the top of the transmission tunnel/firewall
- The engine will move up with it (still connected by the 2 lower bell housing bolts)
8.2 — Disconnect Engine from Transmission
- Put tension on the engine hoist chain to support the engine
- Remove the 2 lower bell housing bolts
- Pry on the bottom of the engine/transmission if needed to get them apart
8.3 — Pull Engine Forward
- Wiggle the engine while pulling forward to separate it from the transmission
- Keep just enough upward tension to prevent the engine from dropping, but not so much that it binds
- Keep the engine as parallel with the transmission input shaft as possible until fully apart
:::caution Critical Clearance Points As you raise and pull the engine forward, watch for:
- A/C compressor — a bolt on the front iron sticks out and can catch it; work side to side until clear
- Passenger side — auxiliary port actuator and MOP* (metering oil pump)
- Manifold to heater core pipe clearance
- Crank pullies will hit the crossbar if not removed beforehand
- ABS module — positioned awkwardly on the driver's side, can interfere during extraction
- Intake manifold — can contact the cowl/firewall area when lifting at steep angles
- Hoses still attached — ensure hoses staying in the car aren't tangled around parts coming out; this is a common snag point :::
:::tip Low Ceiling Garage If the hoist boom hits the ceiling before the engine clears, lower the car on quick jacks to create relative height difference. Shorten chains as much as possible and use a load leveler to tilt the engine during extraction. :::
8.4 — Clear the Engine Bay
- Once the clutch pressure plate is completely clear of the input shaft, raise the engine straight up
- Continue raising slowly, checking clearance on all sides
- The A/C compressor can hang loose and rest on the steering gear
Phase 9 — Engine Out
- Engine is now removed from the vehicle
9.1 — Secure the Transmission
- Replace the cross-member under the transmission
- Lower the jack so the transmission rests on the cross-member
- Reinstall the front wheels
- Lower the car — it can now be rolled around safely while you work on the engine
Reinstallation Notes
| Tip | Detail |
|---|---|
| Pry bar leverage | You'll need a pry bar or pipe for leverage to push the engine back into the transmission — it often won't slide on by hand |
| Wiggle in 2 planes | Adjust angles up/down and side to side to get the engine to mate with the transmission |
| Alignment trick | Put the transmission in gear with the e-brake on, then turn the engine crank to help line up the input shaft with the clutch disc — you'll feel it grab |
| Protect pilot bearing | Pull the engine forward off the input shaft carefully so you don't damage the pilot bearing |
| UIM removal | Remove the upper intake manifold (UIM) to access the top transmission bolts |
| CAT condition | Always check catalytic converter condition before reusing with a new/rebuilt engine |
Fluid Refill After Reinstallation
| Fluid | Quantity | Notes |
|---|---|---|
| Engine oil | ~5.7L | Check on dipstick |
| Coolant (FL-22) | ~9L (2 gallons) | Takes a couple of days to fully bleed — top off before each cold start |
| Fuel & oil | — | Air bleeds itself as soon as the engine starts |
:::info Coolant Bleeding As long as you fill the system with close to 9 litres of coolant, you're close enough to start up. Check and top off for the next couple of days prior to each cold start. :::
Community Tips from Video Sources
Practical advice from experienced RX-8 owners who documented their engine removals on YouTube.
Planning & Approach
| Topic | Advice |
|---|---|
| Transmission | Most experienced mechanics recommend leaving the transmission in the car and pulling only the engine (as described in this guide). Pulling engine + transmission together is heavier, more awkward, and not recommended. |
| Ramps vs stands | Car ramps provide better under-car clearance than jack stands and are more stable for this job |
| Working alone | Feasible with the right equipment (hoist, cross-bar support, ramps). Budget extra time. |
| Expect corrosion | Everything in an RX-8 engine bay corrodes — bolts, lines, fittings. Plan for seized fasteners and have spares for oil cooler lines |
Key Tricks
| Trick | Detail |
|---|---|
| Starter bump for crank bolt | Place a 19mm breaker bar on the front crank pulley bolt, brace it against the frame rail, then bump the starter — the engine rotation cracks the bolt loose instantly. Keep the wiring harness connected until after this step. |
| Rear lifting point | The factory rear lifting tab is very hard to reach with chain hooks. Use nylon lashing straps instead. |
| Shorten chains | Long chains waste vertical clearance. Keep them as short as possible, especially in low-ceiling garages. |
| Low ceiling workaround | Lower the car on jacks to create relative height difference between engine and hoist boom. |
| Hose untangling | Before lifting, verify that all hoses staying in the car are not wrapped around parts that are coming out — a common cause of the engine getting "stuck" mid-extraction. |
| Vice grips on stuck hoses | Clamp vice grips on eroded rubber hoses and wiggle to break them free from metal fittings. |
| Cross-bar support | A Ram or cross-bar across the engine bay + bricks/hardwood under the oil pan supports the engine while you remove mounts without a hoist attached. |
Common Pitfalls
| Pitfall | How to Avoid |
|---|---|
| Rounding off rusty bolts | Use proper 6-point sockets — never 12-point on rusty fasteners. You get one shot at rusty intake bolts; make sure the socket is fully seated. |
| Socket adapter breakage | Don't use 1/2" to 3/8" adapters under heavy torque. They snap on motor mount and cross-member bolts. |
| A/C compressor bolt breakage | These bolts corrode and break. Deal with them while the engine is still supported in the bay. |
| Forgetting electrical connections | Do a visual sweep before lifting. Commonly forgotten: power cross-connect cable to fuse box, main battery cables at the front. |
| A/C lines getting crushed | The A/C lines run near the lifting path and can be crushed or ruptured during engine extraction. Monitor them closely. |
| Block drain bolt on automatics | The AT cooler lines leave almost no room to access or reinstall the block drain bolt. Consider draining coolant from the radiator only on AT cars. |
While the Engine Is Out
Take advantage of the engine bay access while the engine is removed:
- Clean and repaint the engine bay
- Inspect and repair any body rust
- Check all rubber hoses and replace as needed
- Inspect the ABS module area for corrosion
- Verify catalytic converter condition before reinstallation
- Check clutch, pilot bearing, and release bearing condition
Video Sources
| Video | Channel | Link |
|---|---|---|
| DON'T Remove Your Mazda Rx8 Engine Without Watching This | Apex Seal | YouTube |
| How to remove a 2005 Rx8 engine (engine only) | — | YouTube |
| Dorito Removal Complete: Engine Out of the RX8 | Project Doritos Locos | YouTube |
| RX8 Engine Removal!!! RX8 Rebuild Part # 4!! | — | YouTube |
Complete Checklist Summary
Preparation
- Remove hood
- Remove battery, battery box, battery tray
- Remove air filter box and base
- Remove air pump and bracket
- Remove PCM and lid
- Label all coil wiring plugs (1-4) and injector wiring plugs
Electrical
- Disconnect engine-to-chassis harness connectors at junction box
- Unbolt battery harness from crossbar and fuse box
- Disconnect harness connectors above fans
- Unplug A/C compressor connector
Fuel & Vacuum
- Disconnect both fuel lines (save clips and retainers)
- Remove brake booster hose
Belts & Pullies
- Remove A/C belt
- Remove alternator belt
- Remove crank pullies and trigger wheel (4x 10mm) — do NOT remove 19mm e-shaft bolt
Fluids
- Drain coolant at radiator
- Drain coolant at side iron housing
- Drain engine oil
- Lubricate exhaust fasteners
Hoses
- Remove coolant reservoir tank hoses (upper + lower)
- Remove upper radiator hose
- Remove lower radiator hose
- Remove heater core hoses (left + right)
- Remove ground wire on passenger side of LIM
Oil Cooler
- Disconnect oil cooler lines (watch for C-clips and oil spillage)
A/C Compressor
- Remove 2 top bolts
- Remove 2 bottom bolts
- Leave compressor resting on steering gear in the car
Exhaust
- Remove exhaust-to-transmission bracket
- Remove catalytic converter from exhaust manifold (3 nuts)
Drivetrain
- Remove starter
- Remove motor mount top bolts (both sides, 14mm)
- Remove cross-member (17mm + 19mm)
- Remove right motor mount + bracket
- Remove left motor mount bracket (or mount for extra clearance)
Transmission Separation
- Unplug front O2 sensor
- Disconnect rear O2 sensor and connectors
- Remove transmission harness clips
- Remove upper bell housing bolts (2-3)
- Support transmission with jack
- Remove lower bell housing bolts (2)
- Wiggle and pull engine forward off input shaft
Extraction
- Raise front of engine while moving forward in increments
- Watch A/C compressor, auxiliary port actuator, MOP, heater core pipe
- Raise straight up once clear of input shaft
- Secure transmission on cross-member, reinstall wheels, lower car
Denotes steps that may differ slightly for Series II RX-8 (2009-2012 MY).
Sources: RotaryResurrection AGP, 2013 (PDF); Apex Seal YouTube channel; Project Doritos Locos YouTube channel; various community contributors.