Sometimes water drips down onto the back of the air filter box where it hinges to allow opening to replace the airfilter, and this allows water to leak into the front chamber of the airbox. From here it can wet the Air Mass Meter (if you are lucky, as this will stop the car) or get sucked directly into the turbocharger compressor wheel, and thence via the charge cooler directly into the engine! Again: if you are lucky, this might cause hydraulic lock, but can cause bent con. rods etc. (If you get hydraulic lock: take out the glow plugs, and turn the engine over by hand, and the water will squirt out, but you will need to drain all the post compressor induction system too)

Where does the water come from?

Look at the black plastic moulding below the windscreen. It is secured by three self tapping screws at the inferior edge. The middle one of these screws into a plastic insert in the steel bulkhead just above the airfilter box.... In certain situations, when the rain and wind are just right this acts as a spout, and directs a stream of water onto the vulnerable back hinge / joint of the airbox. The water does not come from the air inlet at the front of the grill. The back part of the airbox below the airfilter has drain holes to allow any water coming in with the air to drain out before the air is filtered. However there can be no drain holes once the air has been filtered, as otherwise this would defeat the purpose of having an airfilter, so once the water has gotten into the post airfilter part of the system, it can only go into the engine: as described above.

Not sure anout Fiat fix. Seal screw hole with silicone sealer.

Hope that solves the mystery.

I know this is an old story but I have just come accross this thread while trying to work out what to do with my fiat panda multijet 1.3 (2005, 93K mileage). It had to be towed away after it wouldn't start, the garage advised water in the air filter and I must have been in a flood. I definately haven't driven through a flood but I do live on top of a hill and it has rained a bit lately, even in August! Ironically it had full service and MOT a couple of weeks before, at a different garage.

The garage suggest the options of stripping the engine to work out the damage, if necessary repair valve or rods or worst case scenario new engine or scrap the car. I don't have the money to do costly repairs and the car is getting on, but don't want to scrap it if there is something we can try as it is a lovely economical drive. I will suggest to the garage trying what has been outlined above re plugs etc. If anyone knows how much this type of work could cost, has found links to other forums suggesting solutions or has other suggestions that could work, please post.

Thanks