I have a Kia Sedona and its losing coolant through the header tank due to too much pressure.?

Question

When I take the rad cap off with the engine running ,coolant flows out. What can it be?

Answer 1

Blown head gasket.

$900.00 plus parts.

Answer 2

why do poeple allways assume the head gasket
1. possible airlock in the pipes try bleeding them including the rad.
2 blockage in the system to fix/test remove top pipe from rad end push a hoise into the pipe turn on if wayter flows from the rad then the sytems clear and you have probably blown the head gasket
3 remove the thermostat (follow the top hose to the engine there shoul be a small ally casing called the thermostat housing remove the housing) put the hose on without the thermostat and flush again if water passes through the system take the thermostat indoors put in pan of boiling water and leave for a few minute if the centre of the thermostat moves then see 2 if it does not move replace the thermostat with a new one then refill and bleed the cooling system

the thermostat is the most likley culprit if it is when you buy the new one test it before fitting

Answer 3

The cooling system is pressurised to stop the water boiling, if you remove the cap whilst the engine is running you release the pressure and the water boils over.
You should never release the radiator cap with the engine running it's bloody dangerious !!
Your problem is no doubt caused by a broken head gasket get it checked out at a garage >

Answer 4

NEVER TAKE THE RADIATOR CAP OFF WHILE THE VEHICLE IS RUNNING. the coolant system is pressurized to reduce the boiling point of the coolant, when de-pressurized the coolant boils immediately