The Volvo P2 achilles heel?

The Volvo P2 generation are robust cars that can handle long mileage. One reason is the very good rust protection - galvanized with a thick layer of zinc, protecting plastic trim, and several components in the undercarriage are made out of aluminum, including the whole subframe both in front and rear.

However, the Volvo P2 has one achilles heel, and that is actually rust. The front strut towers may start to rust on the underside, and if untreated it will continue to rust until the rust is visible from the top, under the hood. Then it is rusted through, and very difficult to treat. This may be the end of the car.

Here is a good video explaining the problem:

www.youtube.com/watch?v=a3gNNboxytg

However, if you inspect the strut towers once a year and remove rust before it grows, you may keep your car for a long, long time.

The inspection can easily be done, but since the rust tend to start on the least visible spot, you have to use a mirror or sit inside the wheel arch to be able to see it.

A rusty strut top mount is used as an explanation of this rust problem. However, I believe there is one additional source to this rust problem. If you inspect the tower you will find a gap where the tower "ends". This small gap will get filled with dirt, water and salt. In time this will make the tower start to rust from the bottom, all along the gap. The rust will spread upwards, meeting the strut mount rust that will spread downwards.

Both earlier and later models are vulnerable to this rust from the tower bottom. Here you can see a photo of where the rust starts:

Here is a photo where the surface rust is removed. You can clearly see that in this case the rust from the bottom gap is a much bigger concern than the rust from the strut top mounts.

After cleaning the gap, I would recommend to fill it with butyl sealing to prevent dirt and water entering the gap.