1999 Ford Expedition Problems: 1 Issues Every Owner Should Know
1999 model year · 0+ owner reports · Updated April 2026
According to Au7o's analysis of 0+ owner reports, the 1999 Ford Expedition has 1 documented known issues, with 1 rated critical. The most serious is 5.4L 2-Valve Spark Plug Blow-Out From Cylinder Head ($150-$400 repair). Across all issues, repair costs range from $150 to $400. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 1997-2008 Ford Expedition 5.4L Triton, the 5.4L Triton 2-valve V8 in 1997-2008 Expeditions is notorious for spark plugs ejecting from the aluminum cylinder heads. The 2-valve heads have only 4 threads holding each spark plug, which is insufficient for the clamping force needed. Over time, the threads strip and the spark plug launches out of the head under combustion pressure, taking the ignition coil with it. This typically happens when spark plugs are removed and reinstalled, or spontaneously at high mileage.
Common Symptoms
- Loud popping noise from engine
- Spark plug and coil found on top of engine
- Engine misfire on one cylinder
- Hissing noise from plug hole
- Loss of power and rough running
How to Fix
If a spark plug has blown out, a thread repair kit (Time-Sert or Heli-Coil) can permanently restore the threads without removing the cylinder head ($150-400 per plug at a shop). Prevention: Use anti-seize on spark plug threads, torque to exactly 22-25 ft-lbs (do not overtighten), and avoid changing plugs when the engine is hot. Time-Sert inserts are considered the superior repair ($30-50 per kit DIY). Some shops specialize in this repair and can do it in 30-60 minutes per plug.
What Owners Are Using
Parts and tips from 0+ owners who fixed this issue
- Tip
- UpgradeIridium spark plugs offer long life and consistent performance (NGK Iridium IX Spark Plugs)
- UpgradeAnti-seize compound prevents spark plugs from seizing in aluminum heads (Permatex Anti-Seize Lubricant)