Quick Answer
A rattling noise from your chainsaw can be caused by loose or worn out parts, such as the chain or bar, or by a damaged or bent guide bar.
Cause of Rattling Noise: Loose or Worn Out Parts
A rattling noise from your chainsaw often indicates a problem with the chain or bar. Check the chain tension by pulling the chain tight and then releasing it; if it returns too quickly, it’s too loose. Aim for a tension of 1/4 inch (6-8 mm) when the chain is in its normal running position. If the chain is too tight, it can cause the guide bar to vibrate and produce a rattling noise.
Identifying and Fixing Loose or Worn Out Parts
Inspect the chain and guide bar for any signs of wear or damage. Check for loose or worn out bolts and tighten them according to the manufacturer’s instructions. If the chain or bar is damaged, replace it with a new one that meets or exceeds the manufacturer’s specifications. Use a bar oil to keep the guide bar lubricated and rust-free. For a 16-inch (40 cm) bar, use 1-2 ounces (30-60 ml) of bar oil per 10 hours of use.
Additional Causes of Rattling Noise
In some cases, a rattling noise can be caused by a bent or damaged guide bar. Check the guide bar for any signs of damage or bending. Use a ruler or straightedge to measure the bar’s straightness; if it’s bent more than 1/8 inch (3 mm), replace it. A bent guide bar can cause the chain to vibrate and produce a rattling noise. In rare cases, a rattling noise can be caused by a damaged or loose sprocket or other internal components. Consult the manufacturer’s instructions or a professional mechanic for assistance in diagnosing and fixing these issues.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.