Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2012 Mazda 3 L4-2.5LFACTORY OEM SERVICE PROCEDURE
Cylinder Head Assembly
Cylinder Head
Measure the length of each cylinder head bolt.
Cylinder Head Bolt Length L 145.2-145.8 mm {5.717-5.740 in}
Cylinder Head Bolt Maximum 146.5 mm {5.767 in}
Tighten the cylinder head bolts in the order shown in the following 5 steps using the SST (49 D032 316).
Tightening torque
Step 1 3-11 Nm {31-112 kgf-cm, 27-97 in-lbf}
Step 2 13-17 Nm {133-173 kgf-cm, 116-150 in-lbf}
Step 3 43-47 Nm {4.4-4.7 kgf-m, 32-34 ft-lbf}
Step 4 88-92°
Step 5 88-92°
Camshaft
Temporarily tighten the camshaft cap bolts evenly in 2-3 steps.
Tighten the camshaft cap bolts in the order shown in the following two steps.
Tightening torque
Step 1 5.0-9.0 Nm {51-91 kgf-cm, 45-79 in-lbf}
Step 2 14-17 Nm {1.5-1.7 kgf-m, 11-12 ft-lbf}
Exhaust Manifold Specifications
Camshaft Gear/Sprocket Specifications
Measure the length of each cylinder head bolt.
Cylinder Head Bolt Length L 145.2-145.8 mm {5.717-5.740 in}
Cylinder Head Bolt Maximum 146.5 mm {5.767 in}
Tighten the cylinder head bolts in the order shown in the following 5 steps using the SST (49 D032 316).
Tightening torque
Step 1 3-11 Nm {31-112 kgf-cm, 27-97 in-lbf}
Step 2 13-17 Nm {133-173 kgf-cm, 116-150 in-lbf}
Step 3 43-47 Nm {4.4-4.7 kgf-m, 32-34 ft-lbf}
Step 4 88-92°
Step 5 88-92°
Camshaft
Temporarily tighten the camshaft cap bolts evenly in 2-3 steps.
Tighten the camshaft cap bolts in the order shown in the following two steps.
Tightening torque
Step 1 5.0-9.0 Nm {51-91 kgf-cm, 45-79 in-lbf}
Step 2 14-17 Nm {1.5-1.7 kgf-m, 11-12 ft-lbf}
Exhaust Manifold Specifications
Camshaft Gear/Sprocket Specifications
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.