White smoke and shaking - more than a gasket?

[Ek49ten]

Hi guys. I'm back with another one! You guys are the best online support I have found and appreciate it. So... here it goes, shouldn't be to hard I don't think.

I have a 2000 Pontiac grand am gt with 130k miles on it. It has been very slowly loosing antifreeze sense I got it. Maybe a half gallon a month. I'm not sure if this is a leak or do to this issue now. It has never smoked at all though (I watched this closely when I got it). I mean... no smoke before. Last night I was driving home and it started to overheat (no smoke when driving still). I pulled it over and cooled it off and put a little water in it. When it was cool it started right up and was not smoking. I got about a half mile and it started overheating again. I got it in a gas station and turned it off. I went in and got a bottle of antifreeze and when it was cool it guzzled the entire bottle plus a 1/4 bottle of water. I went to start it and it took about 2 minutes. It acted like it didn't want to start and was struggling. When it finally started it was shaking fairly bad like it was misfiring and there was pure white smoke coming out of the exhaust with a sweet smell and a lot of moisture.

I'm trying to provide as much info on what happened because I know this is probably a blown head-gasket. But I was wondering with those details can you tell if this is more than just a gasket? Like it cracked a head or something? What are other signs of a cracked head? and how much can a cracked head cost? Is the motor toast if this is more than a gasket? I'm really hoping it's just a gasket and hoping it's not to expensive.

[driver540]

Sounds like you blew the gasket. When you added the coolant and water it was filling the oil or cylinders creating the hard start and missing. There is a good chance you may only have to replace the head gaskets. By the sound of it you kept a close enough eye on it to avoid any damage to the heads. The sad part, you can only tell if heads are bad once they are removed. If you decide to fix it, make sure you put a new thermostat in while you will have easy access. Replacing the head gaskets arent too bad of a job. If you do the job, keep us posted and good luck. 8)

[re-tired]

in addition to driver 's excellent advise i would add ..take the heads to a machine shop and have them checked for warpage . this is the main cause of head gasket failure.