1999 Pontiac Grand Prix coolant problem

Hi, Here is the deal. My son bought car and found full of bars leak. We were told intake gasket was bad and had it supposedly changed, doesn't look like it was apart to me but I know
nothing. Car still uses antifreeze. None in the oil, radiator builds up pressure when running and overflows when cap is removed. None on the ground either. This leads my friend to believe it has a cracked head. So I guess my question is could it still be the intake(my friend says the intake won't put pressure and bubbles in the radiator) or is it for sure a head gasket or cracked head, my friend says it is for sure a bad head. Oh, the guy who put the intake gasket in said he did a leak down test on the cylinders and there was no problem, so it is a head problem this also leads me to believe he didn't put the intake gasket in. Thanks for any info with this problem, Kirk
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I forgot to add it is a 3.1L if it makes a difference.

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Kirk Frei wrote:

What do you mean by the above statement? It's normal for the radiator/cooling system to build up pressure when the engine is running, and it's normal for the coolant to overflow when you remove the cap. What would not be normal is if the cooling system were to continue to bubble into the overflow bottle after the engine reached operating temps.
I would suggest that you have the vehicle properly diagnosed.

Your friend is correct about the intake gasket....but the jury is still out on his bad head/gasket theory. More "proper" diagnosis is needed.

I don't think you can draw these conclusions from what you've said here. You may be right, but I'd get another shop to have a look and see. 2nd opinion and all that!
Ian
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Thanks for the info, I was thinking that if the car was running it should not overflow when the radiator cap is removed. Kirk

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You have a leak. Mine did the same thing. 99 Monte 3.1L Sometimes it would travel down the backside of the engine and make a very small puddle. Coolant can evaporate from a small leak also and never make a puddle. Like the quick disconnect heater hose fittings on Chevy p/u's.

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Kirk Frei wrote:

It all depends.....is the engine cold? If you just start the vehicle and it immediately begins to pressure up the cooling system, yes...you may have a problem. If you take the cap off after the engine is hot, there will be pressure in the system...that's normal.
Ian
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