ok i got a game against a empire player and i know there is going to be a stank so here is the question, in combat can the stank only fight the turn it has sp? does it get a free grind in my combat phase. does the tank get to shot its steam canon in h2h so on... LAV your my go to guy do you know?

Stank can only attack on the owning player's turn to my understanding. Even then, it can only do something if it generates the steam points. So do a couple of wounds on it (and hope he doesn't have a life wizard) and it will be useless.

That's correct.
The Stank can only charge SteamPoints in its own phase. So no grinding, shooting, or movement in Your turn. It can also never over-run if breaking a unit in combat. I do believe it may use its cannon in b2b though.

EDIT:
Your best bet against the Stank, as a Daemon player, is definately magic IMO. Remember that the Stank autofails Initiative-tests, which means that a successfully cast Purple Sun or Pit of Shades is all you need to remove it once and for all.

GuO with Balesword and Thirster with Strength 10 would be my next line of 'defense' against the Stank. Just make sure it doesn't get the charge because the crazy contraption can kill just about anything on the charge with a little luck.

As already stated, all you need to do in order to neutralize it is to deal 3-4 wounds. But it's still annoying if it gets one of your big blocks stuck in an eternal combat since it's unbreakable and will stand there to End Game if you don't manage to actually kill it.

as Daemonreign said, magic is your best bet against it. i personally almost never use magic lores that can kill it in one go, so i just charge it with a fiend when it starts to get close enough to charge, and just keep feeding it fiends or furies as long as possible.

IIRC it has a 1+ armour save, so a loremaster with Gold magic is also nasty against it.

thanks guys

Best tips have already been said, but I would like to correct one thing from them. Bloodthirster with awesome strenght really isn't such a great counter against Stank. It only deals around 3,5 wounds to it per turn, which means that it will likely be stuck in combat for 3-4 rounds, which is pretty bad for over 500pts monster. Awesome strenght also makes your thirster quite expensive and it does not give much benefits for anything else.

I'll add one more spell that hasnt been mentioned yet and that would be Miasma of pestilence from Nurgle lore. Get herald of Nurgle and throw it to Stank in melee then finish it off in a 2 rounds with supporting attacks and breath attack. Armour save is tough, but you will likely crack the stank in 2-3 rounds. But in the end, balesword guo is ultimately the best counter. It will automatically deal atleast 3.57 wounds on the first turn even with bad luck and will likely deal 9-12 wounds in a single round against Stank.

Yeah; I'd go with the GuO over any other GD, but I think killing it with fire (i.e., vortexes of doom) is perhaps the most efficient; but I think any Empire player would be just waiting for you to try.

True that Feez, I tests kill it in one shot but in the other hand Empire is notorious for its high magical defenses. All those priests add up in dispel pretty fast.