Onset of dull "knocking" noise in running engine at idle; sound similar to connecting-rod or piston wrist-pin bearing knock, but does not increase in severity or frequency as engine speed changes. Simultaneous significant variation in engine idle speed (+/- 200 RPM @ 1,000 RPM idle), and rough transition to cruising speed. Dealership "found" that the internal plate of the plastic intake manifold had come loose and was shifting to produce sound. Dealership speculates that the engine intake manifold developed air / vacuum leaks, compromising engine idle. Owner deduces that dealer was familiar with similar vehicle problems effecting other Windstar. At minimum, the "knock" could trigger expensive- and unnecessary engine repairs. At worst, the intake manifold malfunction could cause loss-of-power or engine inability to operate, triggering accident. A likely side-effect will be the reduction in engine operating efficiency / increase in fuel consumption, and compromises in engine emissions performance. Situation bears similarities to Ford tsb Sep 01, 2001 NHTSA item number: 625749: "make : Ford model : Windstar year : 2001 manufacturer : Ford Motor Company service bulletin num : 15213 date of bulletin: Sep 01, 2001 NHTSA item number: 625749 component: Engine and engine cooling:engine:gasoline summary: Some vehicles may exhibit an engine noise that sounds like a connecting-rod knock or lifter noise.".

- Long Beach, CA, USA

Bought 2001 Ford Windstar in January 2005 with 40,000 miles on it. In August we had to replace the transmission( 46,000 miles). This was $2000. Then in October we had to replace the engine(49,000 miles) because of the head gasket. Ford quoted us $4800 for this and said the car was out of warranty and would not help us defer the cost in any way. We ended up getting a used engine.

- Marlborough, CT, USA

While driving at low speed and turning, the vehicle stalled with out any warning. Also has problem with the steering wheel and the turn signal working intermittently. The dealer replaced the upper intake manifold gasket and the idle air control valve, however the vehicle stalled again and the dealer replaced idle air control valve again. The power steering fluid was low.

- Germantown, MD, USA

While driving 5 mph, the vehicle stalled. The driver was able to restart and drive the vehicle to the dealer inspection. The mechanic replaced air sensor to the engine. Please fill in additional information dealer is aware of the problem.

- Fort Atkinson, WI, USA

While driving at any speed and without warning intermittently engine would stall, causing the consumer to pull over. Dealer inspected vehicle several times, and replaced different parts, but problem still occurring.

- Elizabeth, NJ, USA

Consumer states that when pressing on the brakes engine starts surging and shaking. Dealer can't duplicate problem.

- Edison, NJ, USA