Ford Mustang: common faults & what to check

Which Ford Mustang are you looking at?

6 generation variants documented. Pick the shape you recognise: the faults, the servicing and the timeline below all narrow to it. Free, no account needed.

Petrol

2 variants documented

2015–2023S5502015–2023S5505.0 V8 petrolPetrolDocumented issues7 knownSee faults & what to checkPhoto: Michael Barera via Wikimedia Commons, CC BY-SA 4.0.

2023–nowS6502023–nowS6505.0 V8 petrolPetrolDocumented issues6 knownSee faults & what to checkPhoto: Alexander-93 via Wikimedia Commons, CC BY-SA 4.0.

Fuel not stated

2 variants documented

2015–2023S5502015–2023S5502.3 EcoBoostFuel not statedDocumented issues5 knownSee faults & what to checkPhoto: Michael Barera via Wikimedia Commons, CC BY-SA 4.0.

2023–nowS6502023–nowS6502.3 EcoBoostFuel not statedDocumented issues5 knownSee faults & what to checkPhoto: Alexander-93 via Wikimedia Commons, CC BY-SA 4.0.

Engine not documented

2 variants documented

1994–2005SN951994–2005SN95Engine not documented for this generationEngine not documentedDocumented issues3 knownSee faults & what to checkPhoto: IFCAR via Wikimedia Commons, Public domain.

2005–2015S1972005–2015S197Engine not documented for this generationEngine not documentedDocumented issues3 knownSee faults & what to checkPhoto: Sicnag via Wikimedia Commons, CC BY 2.0.

Now narrow it to the engine

A 1.8 and a 2.4 of the same car do not fail the same way, so the faults below narrow to the engine as well as the year. Free, no account needed.

Start your free check on this Ford Mustang

No plate needed. You get the risk score, the buyer's checklist and the guided inspection for the exact car you picked above — not the whole nameplate.

The checks worth doing on a Ford Mustang before you hand over any money. Every documented fault is listed below, each with its own page.

• Serious issue

  Check oil level and condition.

  See why

  Coyote 5.0 V8 oil consumption and oil starvation under sustained cornering

  The S550 Coyote 5.0 V8 has insufficient oil drain-back passage capacity for sustained high-lateral-G cornering. Oil collects in the cylinder head and starves the bottom end. Documented heavily in track-day communities. Even street driving with spirited cornering can accelerate wear. High oil consumption between services (up to 1L/1,000km under track use) is a separate but related symptom from the same drain restriction.

  What you would notice

  • Oil level drops between services without visible external leak
  • Blue smoke on overrun after spirited driving
  • Low oil pressure warning light during hard cornering
  • Ticking or rattling from engine after track or canyon driving

  Typically $800–$6,500 to put right.

• Serious issue

  Ask to see the car cold and check the coolant reservoir level before it is started, then look again after the drive.

  See why

  Head gasket failure and coolant loss (3.8 Essex V6, 1994-1998)

  The pre-1999 3.8 Essex V6 pairs aluminium heads with a cast iron block, and the different expansion rates wear and break down the head gaskets, letting coolant into the cylinders or exhaust gas into the cooling system. Left alone it causes overheating, which warps the aluminium heads and turns a gasket job into a heads-and-machining job. Ford ran an extended warranty (98M01) and later extended coverage on related 3.8 vehicles after a class action, but those programmes are long expired. Ford also advised new head bolts with every gasket repair. The 1999-on split-port 3.8 in the New Edge car was revised and head gasket failures became far less common.

  What you would notice

  • Coolant level keeps dropping with no visible leak
  • White sweet-smelling smoke from the exhaust, especially on cold start
  • Temperature gauge climbing in traffic or on hills
  • Bubbles in the coolant reservoir with the engine running
  • Rough idle or misfire on a cold start

  Typically $2,500–$5,500 to put right.

• Serious issue

  Check service history for TSB 17-0007 valve spring replacement.

  See why

  5.0 Coyote V8 Valve Spring Fracture

  Ford issued TSB 17-0007 covering premature valve spring failure on the 5.0L Coyote V8. Springs fracture at high RPM, causing a collapsed valve, misfire, and in severe cases valve-to-piston contact and complete engine failure. The TSB applies to 2011-2017 Coyote engines but failures on S550 (2015+) Mustangs are well documented. A significant proportion of enthusiast-driven Mustangs reach high RPM regularly, making this a material pre-purchase risk in the NZ used market.

  What you would notice

  • Single-cylinder misfire under load at high RPM
  • P030X misfire code for one cylinder
  • Ticking from valve train under load
  • Sudden loss of power accompanied by rough running

  Typically $1,800–$5,500 to put right.

• Serious issue

  Ask for the engine to be cold and stand at the front of the car during start-up.

  See why

  Timing chain tensioner arm and guide wear (4.6 2V V8 GT)

  The 4.6 2V uses two long timing chains with nylon-faced tensioner arms and plastic guides. On 2000-on engines the nylon face can wear through to the aluminium base, the chain goes slack and slaps, the plastic guides break, and debris can block the oil pickup screen. Ford issued a service bulletin for the same wear on 2000-2003 Crown Victoria and Grand Marquis with this engine, and Mustang owners report the same failure at higher mileage. Caught early it is a timing chain kit; if a chain jumps or the oil pickup starves, the engine can be badly damaged.

  What you would notice

  • Rattle or grinding from the front of the engine, loudest on cold start
  • Slapping chain noise at idle that changes with revs
  • Check engine light for cam timing or misfire
  • Fine glittery or plastic particles in the oil

  Typically $2,500–$5,000 to put right.

• Costly issue

  Test cold and warm shifting through all gears, focusing on 1st-2nd.

  See why

  MT82 Manual Gearbox 1st and 2nd Gear Synchro Wear

  The Getrag MT82 6-speed manual fitted to V8 and EcoBoost Mustangs has extensively documented synchroniser wear in 1st and 2nd gear. The unit uses a single-cone synchro design inadequate for the torque output of the 5.0 V8. Symptoms appear from 50,000 km and worsen progressively. Ford issued TSB 12-12-4 and later revised fluid specifications, but the underlying design weakness remained. Documented by Mustang communities in the US, UK, and Australia.

  What you would notice

  • Notchy or crunching shift into 1st or 2nd gear, especially when cold
  • Grinding on aggressive 1-2 shift under load
  • Difficulty selecting 1st from rest
  • Synchro crunch on downshift into 2nd

  Typically $2,200–$5,500 to put right.

• Costly issue

  Start it cold and listen to the idle for an uneven beat, resting a hand on the centre console to feel a shake.

  See why

  4.6 V8 three-valve ignition coil failure and misfire

  The 4.6 three-valve V8 in the S197 Mustang is well known for ignition coils that break down with age and heat, typically somewhere between 50,000 and 130,000 km. A weak coil misfires under load first — pulling uphill or accelerating hard — before it starts affecting idle. Running on a misfire pumps unburnt fuel into the exhaust and can kill a catalytic converter, which is what turns a cheap fix into an expensive one. Coils and plugs are usually done as a set on a car of this age. Related and worth knowing: on 2005-2008 build cars the two-piece spark plugs are notorious for snapping off in the head during removal, so a plug change on those is a job to have done by someone who has met them before.

  What you would notice

  • Shaking or juddering under acceleration, especially uphill
  • Flashing engine warning light — that means an active misfire
  • Rough or uneven idle
  • Loss of power and worse fuel economy

  Typically $400–$2,500 to put right.

Ford Mustang service schedule

What falls due, and at what distance, for each generation of the Ford Mustang. These are the model’s intervals — the car’s own service book is the only thing that can tell you what has actually been done to it.

What these repairs cost on other cars

Some of the Ford Mustang’s documented faults are repairs other models share. Each page lists the documented NZ cost for every model it affects.

• Timing Chain Replacement Cost
• Head Gasket Repair Cost

Other Ford models