Citroen XM Forum

On Saturday I was once again very fortunate to have the use of a local friend's garage and lift that as always proved most helpful. All went fairly well with the work on my car and I managed to thoroughly clean down and liberally apply waxoil in various locations underneath. Unfortunately I ran out of time to replace the front brake pads, which I had recently noticed were heavily worn, plus the clips on the pins were both seized, but I think I may also now fit new discs. Needless to say I found a few other jobs that need doing and principally a split driveshaft outer gaiter to replace! Regards, Matthew T.

Looking good under there Matthew. Very lucky to have access to a lift.

Noticed an interesting early 2cv in the background.

It appears your v6 has a partial undertray with the air suction flap. I presume it couldn't have a full tray due to the exhaust being too close to the plastic.

Well spotted with the 2cv Russ and Kelvin has a number of Citroëns including a late XM sed auto and early BX diesel! Also in the collection is a TR7 wedge!! The condition of the Germany car underneath is quite impressive with relatively light surface rust on the subframes and no damage or repairs to the jacking points or sills elsewhere. I think it is the steel sump plate that you are referring to Will as there is no undertray. Regards, Matthew T..

Hi Matthew. There is defininitely a plastic attachment forming the air exit flap bolted to the front section of the subframe.

Do you mean this Will, which I think is just to deflect any road debris for hitting the underside and I think all my cars have the feature? With regards, Matthew T.

Hi Matthew,

I do mean that lip and it's associated plastic sheet that is riveted underside of the subframe. That lip creates a low pressure point so that air is drawn out of the engine bay behind the radiator. On diesel engined cars that lip is part of the undertray which then cover under the engine, but wouldnt be safe with the heat of the exhaust and Cat touching it.

Undertrays are good for aerodynamics, cooling airflow and stability.

I have learnt something there Will as I thought the lip was purely for protection. The Poland car does not have this feature so it must have been added early in production I guess. I enclose other photos showing the top of the lip and the subframe without the fitting. With regards, Matthew T.

The mandarins original engine seemed to run hotter with the undertray on. So I took it off just to see if it helped and it did. Not by much, but it was cooler. Still got it, ....horribly oily though.

That is an interesting little feature that lip. I did notice it too. Is it a 24v thing maybe, hence the Poland car doesn't have it?

After further checks rather intriguingly only three of my cars have the fitting, which include the two 24v and the earlier 12v auto. Both the Poland and Gold 12v manuals and the later Cobalt auto are without. Regards, Matthew T.