Grand Am Cooling System

My dad took his 1997 Pontiac Grandam SE to his dealer and they put the wrong coolant in his engine and drove it around for 3 months until he took his car to get an oil change where they oil guys discovered the mistake. Nothing happened to the car. But recently he had a leak in the cooling system and when he took it to get it tested at a local car shop they said he had a blown head gasket. But there was no oil or gas leak and the car still starts. Is it possible that the wrong coolant cause a broken head gasket and is it possble for a car to start and run with a broken head gasket. My dad says the car runs fine but heats up quickly. He said it make no noise and only leaks coolant.

Your engine size would help.

But to answer the question No, I doubt that mixing the two was the cause unless it was
overheating every day for 3 months.
You can have a blown gasket and not notice any real difference. No oil contamination, no coolant loose. Maybe low compression in the leaknig cylinder(s).

IMO being a 97' it was probly time for the gakset change anyway.

The engine size is a 2.4L 4 cylinder engine. The only thing is that the car runs fine. There is no noise it starts perfect and even with the cooling system not working, my dad still drives it to the grocery store which is two blocks from where he lives. The car only starts to over-heat if driven for more than 30 minutes. He noticed his coolant leaking when he got back from the airport after he dropped me off at Midway Airport in Chicago. Its about an hour and a half drive there and back.

Also, how much do you think it costs to change a head gasket. The gasket itself isn't expensive but I don't think costs more than $1000 for labor from some local company.

Head gasket on that motor is a major job. I did my 95, took 11 hours with 2 of us working on it. Price it out, I found a place near me that would have done mine for $850 plus parts, but I didn't want to spend that kind of money on it (I'm cheap, car has 270k miles on it) so I did it myself.

it is a labor intensive job that requires so many things to be removed :shakehead

A good shop manual makes a world of differance in doing your own repairs on something like this.

I'd charge about the $1k for the job.
But Heads are hard to find locally for me.

Thanks For Your Help! We aren't sure what will become of the Grand Am now. My step-mom wants to purchase a Jeep Liberty. I don't like the Jeep Liberty but i'm not going to buy it.:rolleyes: