Parts for your 2008 Mitsubishi Outlander-Head gasket

2008 Mitsubishi Outlander head gasket — what it does and when to sort it

Yes, the 2008 Mitsubishi Outlander uses a head gasket. Technical documentation backs this up: the Mitsubishi Motors Workshop Manual for the CW-series Outlander (MY2007–2012) details cylinder head service and gasket specifications for the 2.4‑litre 4B12 and 3.0‑litre 6B31 engines, and Mitsubishi’s ASA electronic parts catalogue lists a “gasket, cylinder head” for those engines. Both are designed around a multi‑layer steel (MLS) gasket sandwiched between the alloy head and the block.

On this Outlander, the head gasket’s job is to keep three critical systems perfectly separate under heat and pressure: combustion, engine oil and coolant. The MLS design tolerates thermal cycles well, maintaining clamp load and sealing as the engine warms and cools. When it’s healthy, there’s strong compression, no oil in coolant, no coolant in oil, and no gas slipping into the cooling passages. That’s what keeps it running sweet under the bonnet on school runs and long Kiwi or Aussie highway hauls alike.

Head gaskets aren’t a scheduled replacement item, so the best “maintenance” is prevention. Stick to the factory service schedule, use the correct spec coolant and engine oil, and never ignore overheating. Cooling system health is everything here: a tired radiator cap, a lazy thermostat, or a weeping water pump can spike temperatures and stress the gasket. If the timing gear is off for other work (belts/chains, water pump), it’s a good chance to inspect for early signs of trouble.

• Watch for tell‑tales: unexplained coolant loss, pressurised hoses from cold, white exhaust steam, milky oil, rough cold starts, or bubbling in the expansion tank.
• If suspected, get a chemical block test, cooling‑system pressure test and compression/leak‑down test.

If a head gasket has failed, a proper repair on the Outlander involves removing the head, checking flatness, crack‑testing, cleaning mating surfaces, and fitting a quality MLS gasket with new torque‑to‑yield head bolts. Follow the workshop’s torque‑angle sequence—no re‑torque required on new TTY bolts. Expect a solid day (4‑cyl) to two days (V6) of labour, and it’s smart to address timing components, thermostat and any tired hoses while you’re in there. Using genuine or premium-equivalent parts and keeping the cooling system pristine will give the new gasket a long, happy life.

• Does the 2008 Outlander have a head gasket on both the 2.4 and 3.0 engines?
  Yes. Both the 2.4‑litre 4B12 four‑cylinder and the 3.0‑litre 6B31 V6 use a multi‑layer steel head gasket between the cylinder head and block, as outlined in Mitsubishi’s CW‑series workshop manual and parts catalogue.
• What symptoms point to a blown head gasket on a 2008 Outlander?
  Common signs include overheating, sweet‑smelling white exhaust steam, milky residue under the oil cap, unexplained coolant loss, hard pressurised radiator hoses from cold, bubbling in the expansion tank, and misfires on start‑up. Testing (block test, pressure test, leak‑down) confirms it.
• Is it safe to keep driving with a suspected head gasket issue?
  Best not. Driving can escalate damage—warped heads, scored bores, even a hydro‑locked cylinder. If the temp gauge climbs or symptoms appear, park it, let it cool, and arrange a tow to a workshop.