ViewController variable release

Question

I added a timer in a VC and when I call the delegate to change the view to another VC I found that the timer is still counting which didnt released as expected

- (void)goTitle {
NSLog(@"go title");
IPAD03ViewController *vc = [[IPAD03ViewController alloc] initWithNibName:@"IPAD03ViewController" bundle:nil];
[viewController.view removeFromSuperview];
[window addSubview:vc.view];

}

Does anyone has any ideas?