Head Gasket Repair Cost Calculator
This blown head gasket repair cost estimator prices a full head gasket replacement by engine configuration (inline-4 vs V6/V8), shop labor rate, head machining add-on and new head bolts — plus a symptom checker and a repair-vs-replace-engine decision gate. 100% anonymous: no email, no phone number, no lead-gen funnel. Planning estimates from 2026 U.S. industry data — always get 3 itemized local quotes before you authorize a teardown.
Repair cost estimator
Blown head gasket symptom checker
Tick every symptom you have seen. This is a screening aid only — it is not a diagnosis, and a head gasket job should never be authorized on symptoms alone.
Repair vs replace-engine vs sell gate
Enter what your car is worth (private-party value). Uses the estimate from the first tab.
What a head gasket does — and why the bill is huge
A head gasket is a thin multi-layer steel seal sandwiched between the engine block and the cylinder head. It keeps combustion pressure, coolant, and oil in their own channels. When it blows — almost always because the engine overheated once — those channels cross-contaminate. The gasket itself is cheap ($180 – $540 for the set); the bill is the teardown: intake and exhaust manifolds, timing components, and accessories all come off to reach the head, which is $1,260 of labor alone on a typical inline-4 $1,590 job.
Head gasket replacement cost by engine configuration
Typical cost at a $140/hr shop rate, new head bolts, no machining — all figures from the estimator engine above.
| Engine | Heads | Book time | Typical total |
|---|---|---|---|
| Inline-4 (I4) | 1 | 8–12 hrs | $1,590 ($1,350 – $2,130) |
| Inline-6 (I6) | 1 | 10–14 hrs | $1,910 ($1,670 – $2,450) |
| V6 | 2 | 12–17 hrs | $2,470 ($2,050 – $3,050) |
| V8 | 2 | 14–19 hrs | $2,810 ($2,370 – $3,410) |
| Boxer / flat-4 (Subaru) | 2 | 14–20 hrs | $2,710 ($2,290 – $3,430) |
The jump from inline to V engines is structural: a V6/V8 has two cylinder heads and two gaskets, so the teardown labor roughly doubles — a V6 runs about $2,470 before machining vs $1,590 for an inline-4. Boxer engines are the outlier: the flat layout leaves no room to work, so the engine often has to come out entirely.
Head machining (resurfacing): the hidden add-on
Overheating warps the cylinder head. Before the new gasket goes on, the head should go to a machine shop to be measured and skimmed flat again — skipping this is the classic reason a fresh gasket fails early. Resurfacing costs about $200–$500 per head (typically $300), so an inline-4 adds about $300 while a V6 adds about $600 for its two heads. Pressure testing and valve work cost extra if the head is cracked.
| Heads to machine | Typical machining cost | When it is needed |
|---|---|---|
| 1 head (I4 / I6) | $200 – $500 | After any serious overheat — always have the head checked |
| 2 heads (V6 / V8 / boxer) | $400 – $1,000 | Same rule; both heads get checked and usually both get skimmed |
Blown head gasket symptoms
Learn to read what the engine is telling you — and what each sign actually proves. No single symptom is a diagnosis; the symptom checker above scores them together.
| Symptom | What it means |
|---|---|
| Thick white (sweet-smelling) exhaust smoke | Coolant is being burned inside a cylinder — the most recognizable sign. A little vapor on a cold morning is normal; a constant thick cloud is not. |
| Milky / chocolate oil on dipstick or filler cap | Coolant mixing with the engine oil. Check the oil, not just the cap — short trips can leave harmless condensation on the cap alone. |
| Engine overheating repeatedly | Hot combustion gases leaking into the cooling system overwhelm it, or coolant loss leaves too little fluid to cool with. |
| Coolant disappearing with no visible leak | It is going somewhere internal — into a cylinder, into the oil, or out the exhaust as steam. |
| Bubbles in the coolant reservoir while running | Cylinder pressure escaping past the gasket into the cooling system. Never open a hot radiator cap to check this. |
| Rough idle / misfire after cold start | Coolant seeping into a cylinder overnight fouls the plug until the engine warms up and burns it off. |
Worked examples
Every figure below is produced by the estimator engine on this page — change the inputs above and you can reproduce each one.
Inline-4 sedan, no machining
The straightforward case: one head, flat and true, no machine shop.
Estimate: $1,590 (typical range $1,350 – $2,130)
Breakdown: labor 9 hrs × $140 = $1,260; gasket set $240; new head bolts $90.
V6 with warped head (machining)
Overheated once on the highway: both heads need resurfacing.
Estimate: $3,070 (typical range $2,450 – $4,050)
Breakdown: labor $1,960; gasket set $420; machining 2 heads $600; bolts $90.
Subaru boxer-4, engine-out + machining
Flat engine, no room to work: the engine comes out for the job.
Estimate: $3,310 (typical range $2,690 – $4,430)
Breakdown: labor $2,240; gasket set $380; machining $600; bolts $90.
The repair-vs-scrap decision
A $3,070 V6 repair on a car worth $3,000.
Bill = 102.3% of car value — repair exceeds what the car is worth
Consider a used-engine replacement ($3,500 – $7,000 installed) or selling as-is / for scrap ($300–$1,000).
Frequently asked questions
How much does it cost to replace a head gasket?
For 2026, a blown head gasket repair typically costs $900–$2,500+ nationally. This estimator prices a straightforward inline-4 job at about $1,590 (typical range $1,350 – $2,130) at a $140/hr shop rate — $1,260 labor (9 book hours), $240 for the gasket set, and $90 for new head bolts. V6/V8 and boxer engines run higher because they have two cylinder heads.
Why does a V6 head gasket job cost so much more than a 4-cylinder?
A V6 has two cylinder heads and two head gaskets, so the teardown is roughly doubled: about 14 book hours vs 9 for an inline-4. This estimator prices a V6 with head machining at about $3,070 (range $2,450 – $4,050) — $1,960 labor, $420 gasket set, $600 machining for both heads, and $90 bolts — nearly twice the inline-4 job.
What does head machining (resurfacing) add to the bill?
Resurfacing a warped head at a machine shop costs about $200–$500 per head. On a 4-cylinder that adds about $300 to the mid estimate ($1,890 with machining vs $1,590 without); on a V6 with two heads it adds about $600. Any engine that overheated badly enough to blow the gasket should have the head checked for warpage.
How long does head gasket replacement take?
Book time runs 8–20 hours depending on configuration: ~9 hours for an inline-4, ~14 for a V6, ~16 for a V8 or Subaru boxer — and a boxer often needs the engine pulled, which pushes it to the top of the range. That is why labor, not the gasket itself, is most of the bill.
What are the symptoms of a blown head gasket?
The classic signs are thick sweet-smelling white exhaust smoke, milky or chocolate-colored oil on the dipstick or filler cap, repeated overheating, coolant vanishing with no visible leak, bubbles in the coolant reservoir while the engine runs, and rough idle or misfire after a cold start. Try the symptom checker above — but confirm with a combustion-gas (block) test or compression test before authorizing a teardown.
Can you drive with a blown head gasket?
You can, but you should not. Combustion gases in the cooling system and coolant in the oil destroy bearings and can crack or warp the head further — turning a $1,590 gasket job into a full engine replacement. If the temperature gauge spikes, pull over and shut the engine off.
Is it worth fixing a blown head gasket?
Compare the bill to the car’s value with the decision gate above. As an example, a $3,070 V6 repair on a car worth $3,000 is 102.3% of its value — the repair exceeds what the car is worth, so selling as-is or replacing the engine usually makes more sense. The rule of thumb: under ~50% of value, repair; over ~70%, reconsider the car.
Should I replace the engine instead of the head gasket?
A used-engine replacement typically runs $3,500 – $7,000 installed — more than most head gasket jobs, but sensible when the block or head is cracked, the mileage is very high, or the car is worth little more than the gasket bill. Ask the shop to price both options in writing.
Do the head bolts need to be replaced?
Yes — most modern engines use torque-to-yield (TTY) head bolts that stretch on installation and must not be reused. A new set costs about $50–$130, and this estimator includes $90 for them by default. Reusing stretched bolts risks the new gasket failing early.
Can a blown head gasket be fixed with a sealant additive?
Pour-in sealants are a temporary gamble, not a repair: they rarely seal a real breach for long and can clog the heater core and radiator, making the final repair more expensive. No reputable shop warranties a sealant fix. Budget for the real job — about $1,590 for a typical inline-4.
How much does it cost to machine a warped cylinder head?
About $200–$500 per head at an automotive machine shop — typically $300 for a straightforward resurfacing, more for pressure testing or valve work. Inline engines have one head; V6/V8/boxer engines have two, doubling this line item (about $600 on a V6).
Why is a Subaru head gasket job so expensive?
The boxer engine’s cylinders lie flat, leaving almost no room to work — the engine often has to come out of the car. This estimator prices a boxer-4 with machining at about $3,310 (range $2,690 – $4,430): $2,240 labor (16 book hours), $380 gasket set, $600 machining, $90 bolts. It is one of the priciest mainstream head gasket jobs.
Related auto tools
Sources: wanasignauto.com head gasket replacement cost guide; airtasker.com US head gasket repair cost data; cartreatments.com 2026 blown head gasket guide; bumper.co UK head gasket cost guide; golden-horse.ae head gasket repair calculator. Full citations in SOURCES.md.
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