When overheating occurs only at high speed driving, it indicates inefficient cooling and the most common problem is partially clogged radiator. Normal flushing by draining and refilling the coolant does not help.
Remove the radiator cap and drain the coolant slightly, sufficient for you to have a look at the radiator core internals with the aid of a torchlight. If sediments are present, the radiator core is partially clogged and you would have to service or replace the radiator.
Thursday, August 20th, 2009 AT 2:04 PM