Selling a Car With a Blown Head Gasket: Repair It or Move It On?

White smoke from the exhaust, mayonnaise under the oil cap, a temperature needle with a mind of its own. Head gasket failure is one of the most common reasons a good car suddenly becomes a decision, because the fix is labour-heavy and the quote often rivals the car's value.

Here is how to make that decision quickly, and what the car is worth either way.

The repair maths

A head gasket itself is a cheap part. The cost is the hours: stripping the top of the engine, skimming the head if it has warped, and rebuilding. On some engines it is a straightforward day; on others it is engine-out money. The dividing line for repair is usually whether the head warped or cracked from overheating. Caught early on a car you like, repair can make sense. Driven hot for weeks, the damage compounds and the retail quote climbs past sensible.

The critical rule while you decide: stop driving it. Every hot run risks turning a head-gasket car into a scrap-engine car, and that distinction is worth real money.

What it's worth to the trade

More than you think, for one reason: to a rebuilder, a head gasket job at trade cost is routine work, and to a breaker your car is a healthy gearbox, body, interior and electronics wearing one sick engine. Cars with confirmed head gasket failure but honest history sell reliably to both. What kills value is mystery. "Overheats, cause unknown" gets priced as a possible cracked block; "head gasket confirmed by garage, report available" gets priced as the known job it is.

How to list it

State the symptoms precisely and when they started. Include any diagnosis paperwork, the service history, and whether the car still starts and idles. Photograph the whole car, the engine bay and the oil cap honestly. If a garage quoted the repair, mention the figure; it anchors buyers to the retail cost you avoided and frames your price as the bargain it is.

Skip the scrap quote

A scrap price values your car by weight, as if the head gasket took the interior, panels and gearbox with it. The trade values everything the failure did not touch. List free on Second Gears, let verified UK trade buyers, rebuilders, breakers and dealers, make direct offers, and let the buyer handle collection.

List your car free on Second Gears. Sell direct, not at auction, and keep the difference.