Head Gasket Replacement
Also called engine head gasket blown
The head gasket seals the cylinder head to the block, keeping combustion pressure, coolant and oil in their own passages. When it fails you get coolant loss without a visible leak, white exhaust smoke, oil and coolant mixing, or bubbles in the expansion tank. Replacing it means removing the head and checking it is still flat, because overheating warps heads and a new gasket on a warped head fails again. If the head is warped or cracked, machining or repair is quoted separately.
What the job includes
- Confirmation by pressure test and combustion gas test before removal
- Cylinder head removal and inspection of the gasket failure point
- Head checked for flatness and crack tested where there is doubt
- New head gasket set, head bolts and any single-use fasteners
- Timing components inspected and reset to specification on rebuild
- Cooling system refilled, bled, and monitored over a full heat cycle
Signs you need this
- Coolant level drops with no external leak anywhere
- White smoke or steam from the exhaust that does not clear
- Bubbles or exhaust smell in the coolant expansion tank
- Creamy deposit under the oil filler cap or on the dipstick
- Overheating that returns soon after the coolant is topped up
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
Confirm the failure
A combustion gas test and a cooling system pressure test confirm the gasket before the engine is opened.
Remove the head
Timing is marked, the head is removed in the correct sequence, and the gasket is examined to see where it let go.
Check the head
Flatness is measured with a straight edge and feeler gauge, and the head is crack tested or skimmed if required.
Rebuild with new parts
Faces are cleaned, a new gasket and new head bolts are fitted, and the bolts are torqued in sequence and angle.
Heat cycle and verify
The system is bled, the engine brought to temperature and cooled, then coolant, oil and compression are rechecked.
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 head gasket replacement
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.