Cylinder Head Repair
Also called engine head repair
Cylinder head repair covers the work done once the head is off: measuring and skimming a warped face, cutting valve seats, replacing burnt valves, worn guides and hardened stem seals, and crack testing. Heads warp after overheating and valves burn on engines run hard, which is common on CNG converted cars. Repair restores compression and sealing. It does not address wear in the block below, so if bores or bearings are also worn the head work alone will not restore the engine.
What the job includes
- Head stripped, cleaned and inspected with findings shown to you
- Flatness measured and the face skimmed where it is within limits
- Crack testing before any machining money is spent
- Valves, guides and stem seals inspected and replaced as needed
- Valve seats cut and valves lapped so each cylinder seals
- Reassembly with new gaskets and correct valve clearances set
Signs you need this
- Compression low on one or two cylinders with a leakage test showing escape past the valves
- Persistent misfire on the same cylinder after ignition and fuel checks
- Coolant loss or overheating after a previous head gasket repair
- Ticking from the top of the engine with uneven valve clearances
- Blue smoke at start-up, which often points to worn valve stem seals
Not all of these have to be present, and one of them on its own can mean something else entirely. That is what the diagnosis is for.
How we do it
Strip and clean
The head is dismantled and cleaned so the true condition of valves, seats and the sealing face can be seen.
Measure and crack test
Flatness and valve wear are measured and the head is checked for cracks before any machining is quoted.
Machine and replace
The face is skimmed within limits, seats are cut, and worn valves, guides and stem seals are replaced.
Seal test and rebuild
Each port is tested for sealing, then the head is rebuilt with new seals and springs checked for free length.
Refit and set clearances
The head is fitted with a new gasket and bolts, timing is set, and valve clearances are adjusted to specification.
How we work
The same on every job, which is why we can write it down.
Diagnosis before quote
We find the fault first. A price given over the phone for a noise nobody has heard is a guess.
The price is agreed first
You approve the work and the cost before a spanner is picked up. Extra work means another call.
Parts you can check
We tell you whether a part is genuine, OEM, aftermarket or used, and what each one costs.
Old parts returned
Ask and we will hand back whatever we replaced. It is the simplest proof that the job was done.
Book cylinder head repair
Fill this in and a person will call you back to confirm the time and the price. Only your name and one way to reach you are required.
Before you book
Questions we get asked
If your question is not here, ask it. We would rather answer honestly now than have you find out after booking.