How to Remove a Stuck Cylinder Head Bolt

Removing a cylinder head is a tough job. Running into frozen cylinder head bolts makes the job even harder. Fortunately, there are tricks to removing a stubborn cylinder head bolt that will make life a lot easier.

Method 1 of 3: Use a breaker bar

Materials Needed

using a breaker bar to remove the head bolts

Step 1: Use a breaker bar. Head bolts are usually torqued down really tight.

One way to remove really tight head bolts is with a breaker bar. This method allows for more leverage than a traditional ratchet and socket.

Method 2 of 3: Use impact force

Materials Needed

using an impact wrench

Step 1: Use impact force. You can hit the center or the head of the bolt with a chisel or punch to try to free the corrosion between the threads.

An alternate approach to this method is to use an impact wrench on the bolt a several times in both the forward and reverse directions.

Method 3 of 3: Drill the bolt out

Materials Needed

  • Chisel
  • Drill
  • Hammer
  • Protective gloves
  • Repair manuals
  • Safety glasses
  • Screw extractor

hole punched in the top of the bolt

Step 1: Punch a notch in the top of the bolt. Use a hammer and punch to make a notch in the top of the bolt.

This serves as a guide for your drill bit.

drilling out the bolt

Step 2: Drill through the bolt. Use a drill bit one size larger than the notch made with the chisel to drill straight through the bolt.

Then, follow up by drilling through the bolt again using a bit that can drill a hole large enough for a screw extractor or easy out.

using a screw extractor

Step 3: Remove the bolt. Hammer an “easy out” or screw extractor into the hole you drilled.

Then, turn the tool counterclockwise to remove the bolt. You may need to hold the head of the tool with a pipe wrench or locking pliers.

Head removal and repair is a job best left to professionals. As you can see, the task can get really nasty if things don’t go as planned. If you’d prefer to leave your cylinder head repair to a professional, give the experts at YourMechanic a call.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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