Well done fik c it is always good to get feed back rather than like some guys who just keep quiet once they have got the information and fixed the problem.......... I have come across blocked manifolds on the Toyota 4Y engine a lot, seems to be when the engine starts to get a little bit worn and starts to breath through the PCV valve, the gunge then builds up on the hot spot between the exhaust and inlet manifold...........I have seen them so you can hardly get a screwdriver through the hole!