Sedona 2003 Pressure In Radiator When Starting The Car

[gvelarde]

Hello,
I Was Planning To Buy A Used 2003 Sedona With 130k, The Park Is Been Park For Several Days, When Started I Opened The Radiator Cap After 10 Seconds And A Lot Of Air Pressure Came Out, About 30 To 40psi, Is This Normal In This Kind Of Vans??? I Accelerated In Parking Mode For Few Minutes And Temperture Was No More Than 1/2 The Indication... Someone Knows If This Is Normal?
Thanks

[ron1004]

Welcome to the forum.

That sounds like the cylinder head gasket is gone and the combustion gases pressurising the cooling system.

The fact that it doesn't overheat after a few minutes in the parking lot means that the cooling system is OK, but if the head gasket is gone it will soon displace the coolant and you'll find it start overheating.

I'd stay well clear of this car.

[gvelarde]

Thanks for your answer RON1004, I'm not an expert in cars, but searching on the internet i found that in some makes / years/ models (not necessarily the kia sedona) the water pump starts as soon you start the car and generate this compression automatically... I guess for your answer that this is not the case for the Kia Sedona right? Fixing the gasket is too expensive???
thanks

[ron1004]

Originally Posted by gvelarde

Thanks for your answer RON1004, I'm not an expert in cars, but searching on the internet i found that in some makes / years/ models (not necessarily the kia sedona) the water pump starts as soon you start the car and generate this compression automatically... I guess for your answer that this is not the case for the Kia Sedona right? Fixing the gasket is too expensive???
thanks

Almost all cars I know the water pump is driven off the v-belt or timing belt and run when the engine runs, but the water pumps do not generate any pressure in the cooling system - the pump of course does had a discharge pressure but that does not pressurise the coolant system.
What I understand from your description is that you have pressurised gas coming out the cooling system long before the engine has warmed up, and in that case it points towards a blown head gasket - if you had access to the car long enough before purchasing it, you'd notice that it's losing coolant.

Fixing the gasket is quite expensive and it would be prudent to get the cylinder head overhauled at the same time, or at least skimmed.