No
You can catch Heatran in stark mountain. You end up defeating team galactic and you lead buck to the magma stone. Heatran will appear after you speak with buck in the back of stark mountain. I think your thinking of Diamond or Pearl, I tried it in Platinum. Doesn't work.
After buck has gone back into Stark mountain with it you go back in talk to him he leaves you take the magma stone and Heatran apppears (lvl 50).
Yes, Heatran can be found in Mt Stark (You need to have gone through once with Buck already), he will place the Magma stone back, Heatran will return.
get heatran
Visit stark mountain a second time and you should battle heatran and keep the stone. I do not know completely because I have platinum
in Stark Mountain. need magma stone
Heatran is encountered at level 70. Heatran lives at the top of Stark Mountain. Go to the top of Stark Mountain with a trainer named Buck. Buck will then take the Magma Stone and leave Stark Mountain, which causes the mountain to act up. Talk to Buck at his house, and he will put the stone back. Go back to the top of Stark Mountain and Heatran will be there in the place of the Magma Stone.
stark mountain
well.... you get heatran in stark mountain which is close to resort area u go in there and beat team galactic then u come out then u haft to go back in to get the magma stone in doing that you wake up heatran and then u battle him hope you get him
help buck get to the magma stone then go to the house next to the Pokemon center in the survival area then talk to buck then go to where the magma stone was and heatran will be there
Stark Mountain (where Heatran is)
in stark mountain