coolant leak

O.K... So I have been looking around the forum and think that I might have a good idea about what is going on/wrong but I still have a question. I own a 99 alero/v6 3400. Yesterday I was driving and lost what I would guess was a large amount of my coolant in the span of a grocery store parking lot. I could drive home with low coolant light coming on only for a short while but noticed the temperature gage slowly rising. My question is this... I see a lot of info about the infamous lower intake manifold problem, does it make sense that this could be the problem even though it seemed to puke out most of my coolant all at once? The manifold problem seems like more of a leak thing but that could just be me thinking of previous leaky gaskets I've dealt with in the past. Any info. would be great. Also if it is the manifold how difficult is it to repair. I'm not a gearhead but I'm not afraid to try. Again, thanks for any info. oldE

There are a number of threads with some very good information about the LIM leak problem and how to do the actual job, including some with photos.

If the coolant loss was all at once and it was visibly leaking onto the ground, it may be something other than the LIM gasket (like a hose, radiator, or water pump). If the loss was over a period of time, and just finally got low enough to actuate the light, then it could be a LIM gasket. The two most common external leak points of the LIM are at the front of the engine just behind and below the power steering pump and at the back of the engine just below and forward of the throttle body. Both areas can be seen with a flashlight. If there is a puddle of coolant in either area, you most likely have an LIM gasket leak.

Either way, the best way to detect the leak is to have the cooling system pressure tested.

As for doing the job yourself, it's not extremely difficult, but can be time consuming and will require some special tools, such as a crow foot or swivel socket to get to two of the LIM bolts, and a torque wrench.

jr6078 thank you! You are my first reply on one of these things and I was beginning to give up hope. The way it seemed to me it just dumped out all at one time, however, to be honest I hadn't paid much attention to the coolant before this. Other than checking the pressure what do you think the best thing I can do is? When it happened I popped the hood but by that time it was pretty wet in there. Should I put water in it now that it is dry and see where it is leaking from? Do I have to use coolant? I have been looking at the other posts and have gotten a better idea about what it will take to replace the LIMG. It sounds doable. Again thank you for your attention, you've lifted my spirits.