Bottom Line Up Front
If a cylinder head bolt looks OK, you might think it’s safe to reuse it. In most cases, that’s a mistake – certain bolts must be replaced every time you work on the head.
When to Replace or Reuse Cylinder Head Bolts – A Practical Guide
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Image: When to Replace or Reuse Cylinder Head Bolts – A Practical Guide – Performance Comparison and Specifications
Design & Looks
Not all bolts are created equal. Some are simple hex bolts that can be reused if they’re clean and undamaged. Others, like torque‑to‑yield (TTY) or ARP performance bolts, are designed to stretch and stay stretched after the first installation. Visually, TTY bolts look like regular bolts but feel softer when you try to turn them. If you see any signs of stretching, corrosion, or stripped threads, throw them away.
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Performance & Mileage
Using the right bolt affects engine reliability more than you might think. A reused TTY bolt can lose its calibrated stretch, leading to uneven clamping force. That can cause head gasket leaks, overheating, or loss of compression – problems that show up as reduced mileage or power.
- Reuse‑safe bolts: standard steel bolts, fully threaded, no stretch design.
- Replace‑only bolts: torque‑to‑yield, ARP (often marked with a logo), and any bolt that came with a torque angle specification.
Price & Rivals
New bolts aren’t expensive – a set of standard bolts may cost $20‑$40, while a set of TTY bolts can run $60‑$120. The real cost is in the potential engine damage if you reuse the wrong type. Compare that to the peace of mind of a fresh, correctly torqued set.
| Engine | Mileage | Price | Top Features |
|---|---|---|---|
| 2.0 L I4 | 30 MPG | $3,500 | Turbocharged, Direct Injection, Aluminum Block |
FAQ
- Can I reuse cylinder head bolts on any engine? No. Only bolts that are not torque‑to‑yield and show no damage can be safely reused.
- What happens if I reuse a torque‑to‑yield bolt? The bolt may not achieve the correct clamping force, leading to head gasket failure or warped heads.
- How often should I replace cylinder head bolts? Replace them every time you remove the head if they are TTY or ARP bolts; otherwise, inspect and reuse only if they’re in perfect condition.
Got a story about bolt mishaps or a tip that saved you a repair bill? Drop a comment below – we’d love to hear it.
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Source: Read Official News