Vehicles taking damage for no reason?

[voltex]

I don't really know how to explain this other than sometimes during/after a battle my vehicle will continue taking damage by unknown means, It will drop off in chunks of around 100hp I think and I can't determine the cause of it, the only thing I can think of is I'm still being hit but for some reason just cant see the projectiles but it even happens if I'm behind cover. There have even been times when I've gone from full to less than half health with no idea of what is hitting me.

This has been happening to me for a while but seems to be happening more often recently and the only vehicles I've had this problem with are the med, mammoth and flame tanks, I'll try to record a demo to review the next time it starts to happen if I can remember.