Part 1. Preparation and safety
Objective
- Remove the cylinder heads.
Personal safety
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:
- Work clothing - such as coveralls and steel-capped footwear
- Eye protection - such as safety glasses and face masks
- Ear protection - such as earmuffs and earplugs
- Hand protection - such as rubber gloves and barrier cream
- Respiratory equipment - such as face masks and valved respirators
If you are not certain what is appropriate or required, ask your supervisor.
Safety check
- Some engine parts are very heavy get assistance to lift heavy or awkward parts like the cylinder heads.
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- Mark the heads before removing them they must be replaced back onto the correct side of the block.
- Head gaskets and sealing surfaces can often show clues as to possible causes of engine faults.
Part 2: Step-by-step instruction
- Remove cylinder head bolts
On this engine, some of the bolts that hold the cylinder heads on are under where the valve covers were, and the others are on the outside of the block near where the spark plugs were.
Remove these bolts and put them into a marked bag or bin, but leave two of them in place in the corners. Loosen them, and leave them threaded in three or four turns. When you break the seal of the head gasket, these bolts will stop the head falling off.
- Mark the heads
Before the heads come off make sure that you put an identifying mark on at least one of the heads so you know which head goes on which side of the block.
- Loosen the cylinder heads
Double-check that the safety pin is in your engine stand so the weight of the engine doesn't shift when you try to loosen the heads.
Insert a pry bar or a long socket wrench handle into one of the intake port openings of the head and give it a firm push. You don't want to damage the inside of the intake port so don't push too hard.
- Remove the cylinder heads
Then, remove the safety bolts from the head. Put a few fingers in one of the intake ports and your other hand in an exhaust port to get a good grip before carefully lifting it. Cylinder heads are very heavy, especially if you have a big block, so get some help with this if you need it.
- Look for engine problem evidence
These crusty flakes inside the combustion chamber are burned oil, which is a good indication of worn valve guides. The brown rusty spots on the head gasket, where the water flows from the block into the head, tells you that the motor has suffered some overheating.
Engine symptoms can often be diagnosed by looking at the sealing surfaces of the old gaskets, which sometimes stick to the head, sometimes to the block.
