hi, my astra 1.7 dti 2001 van with 93,000 miles on the clock. recently the header tank has been letting of steam, the fan doesnt come on and it doesnt overheat. i havent driven the van for over half hour. but i think if i had driven it for longer, the tank or tubes would blow.
i took the thermostat out today. tested it. it is working. left it out and theres still some pressure building up in the cooler pipes, iv attached a pic to show where its building up. http://s758.photobucket.com/albums/x...rent=astra.jpg

theres no water in the oil, oil in the water. the exhaust blows no smoke at all, im out of ideas to whats wrong so i need some help please. if anyones in swansea and wouldnt mind taking a look id be really grateful.
1 more question is this the right haynes manual for the van http://cgi.ebay.co.uk/Vauxhall-Opel-...item563bb3654c
thanks alot.