Metal plugs aka rust traps

[mike.p.smith915]

Hi,

Does anyone know if the metal plugs found in the XJS floor pan have a purpose other than causing localised corrosion?

In the process of restoring my car I am finding the plugs look ok inside the car but underneath they have allowed water to get into the under-seal and caused localised rusting. In some cases sections of the floor have needed to be replaced as a result.

They look like drain plugs (see attached) but why you would need so many I don't know which makes me wonder are they there for a different purpose e.g. to prevent resonance in the floor pan or to allow for heat expansion.

The reason for asking is I am closing these off with fresh steel as I restore the car to prevent further rust penetration. I just want to be sure I am not causing another problem by doing so.

Thoughts welcome?

Regards
Mike

[almcl]

I believe the holes are there to let the fluid out from, for example, the floor pan when the body goes through the anti corrosion 'bath' prior to painting during the production process. The plugs are then inserted afterwards, but of course haven't had the same degree of protection, which might explain the corrosion. There was a picture of this in the early Series XJ model brochures.
Don't think there's any harm in taking them out and welding the hole shut, but it's a dead give away that the floor has been repaired?

[mike.p.smith915]

Hi Al,

Thank you for your reply. That makes sense. I couldn't understand why you would need so many drains for something like rain water getting in or any fluid leaks. Good point on originality. If the plugs are OK underneath I will leave them in place and make sure they are well undersealed. If the floor has already gone then I am ok to show it has been repaired.

Thank you again.

Regards
Mike

[Mercury RV]

Hi, You could always do what I will be doing which is to remove ALL the metal plugs and treat the exposed metal edges, then take the correct size rubber grommet, coat the edges with Dinitrol ML wax and replace them, the rubbers don't corrode of course and make a water tight seal, not sure really why Jaguar did not use rubber grommets, perhaps we will never know. Have you also seen how many there are in the floorpan as well and under the rear seat base!! Kindest regards, Simon (Kent)