Inlet Manifold Fault - Duratec

Background

The 1.8 and 2.0 Duratec-HE petrol engines fitted to Mk3 Mondeos have swirl plates (also called tumble flaps) fitted in the inlet tracts to modify the incoming airflow under certain conditions for allegedly improved smoothness, economy and emissions.

However, the flaps in early vehicles (built up to late 2002) are susceptible to falling apart and getting ingested by the engine. This frequently causes engine damage and has caused several vehicles to be written off. Sometimes this is preceded for a long time by an audible rattle, other times failure is sudden and catastrophic.

Ford are not accepting any liability for this, so don't expect a result there. Feel free to voice your displeasure to them, though.

Affected vehicles

The exact date of introduction of the revised manifold - which appears to have cured the issue - is not exactly known. The closest we can say at the moment is that a 2.0 litre car built on 28 August 2002 had the old manifold, and a 1.8 litre car built on 4 December 2002 had the revised one. Check your build date at eTIS (free registration).

How can I tell if I'm affected?

If your car is from around the changeover point, or if you're unsure if the work's already been carried out by a previous owner, the easiest way to establish if your car is affected is to measure the diameter of the oil separator pipe. This seems to have been changed at the same time as the revised manifold was introduced. If the pipe is ½" (just under 13mm) outside diameter, you have the old separator and manifold; if it's ¾" (19mm), you have the new parts. Of course, it's possible an old manifold has been fixed in the past without upgrading the separator.

Unfortunately, this pipe isn't particularly easy to see or access to measure. You need to remove the engine cover first, then your best view of it is with a torch down the gap between the rightmost two cylinders as you look at the engine. Here's a diagram showing the pipe with the manifold removed:

The photos below show this pipe being checked with a 15mm open-ended spanner inserted in the gap below the throttle body - the old pipe would fit inside 15mm, but as this car has the new pipe, it doesn't fit. You really don't want to drop anything down there - this spanner has a ring on the other end with an old piece of speaker cable threaded through it to act as a safety rope. You could make a gauge out of stout cardboard with "jaws" around 15mm across if you don't have a suitable spanner to hand.

The car in the photos has been converted to LPG, so ignore the bank of injectors at the top of the first photo. Use the fuel rail pulse damper (the shiny cylindrical thing with the black vacuum pipe) just left of centre to locate the area in the engine bay that you need to look.

What happens if it breaks?

Read Robert Jenkins' article for the gory details.

How can I tell if failure is imminent?

Hold the pointy end of a screwdriver on each inlet tract of your running engine in turn, putting the blunt end to your ear. The usual safety notes apply - don't wear a tie or dangle long hair into a running engine. If you can hear a rattle (as opposed to the normal injector ticking sound), you have a problem. However, no rattle doesn't necessarily mean no problem.

What can I do about it?

You have four options, that you can either implement yourself or get a garage to do. Removing the manifold is a fairly lengthy but not particularly tricky job and is covered in a separate article, or alternatively, get the Haynes manual.

• Do nothing. Not recommended, as failure can be sudden.
• Remove the flaps and rods completely, and seal up the holes with something like Araldite. Several MEG members have done this and at least one (Dazzaman) has successfully passed an MoT test. A cheap solution that requires a moderate level of skill.
• Replace the valves. A kit was available early on to permit this to be done, and that seems to be available again now. This solution is cheaper and easier than the next one, and retains the intended function of the flaps. You may also choose to upgrade the oil separator at the same time.
• Replace the entire manifold. This is the expensive and comprehensive option. Either use a second-hand manifold from a 2003 or later car, or buy a new one direct from Ford.

More details on all of these can be found in this thread.