I have read that the valve seals on the V6 motor go hard and should be replaced at 100000k, anybody know of this?

On the second Gen TR/TS this is common.

3rd Gens the issue has been resolved pretty much.

Unfortunately it's extremely common on the 6G72 12 valve engine (TR-TS V6).

It can also be a very expensive fix, with some places charging in excess of $900 to change the 12 seals, which cost about $30 from Mitsubishi.

As Gas_Hed said, the problem was resolved on the 24 valve TE-TL motors, by using a different material in the seals, and having different seals for exhaust and intake valves.

I have read that the valve seals on the V6 motor go hard and should be replaced at 100000k, anybody know of this?
How long they last depends very much on circumstances.

I'm just getting ready to change the seals on my TR V6 at 230,000 Km. Oil consumption has gone up and I see blue smoke on starting after leaving standing over night.

Rob

go and give Madmagna a pm on this forum
he's very cheap and very good
and yes he did mine