is the intake valve gasket going to give me problems on a 2003 pantiac montana with 79000 miles and if so how can i prevent it or fix it?

There is no known way to prevent it and it does not happen to all the gm 3.1/3.4 engines, My mom has a 04 Montana and has 255000kms on it and only maintance has been done to it. The only way to fix it is to take the top (most) of the engine apart and put the new "good" gaskets on. I have a 02 malibu with the 3.1 and no problems. As I said it does not happen to all of them, but it has been a pain/nasty mark for GM, as seeing they are not going to fix if the cars that are out of warranty as this will affect over a million auto (small guess). I find that the 3.1/3.4 are really good engines and run good. But this is one of the only issues with these engines, but it can be a nasty repair, sometimes if it is not noticed right away, the whole engine is scrap. Sorry about the bad news.

agreed

I've owned two Montannas - 02 and 04. The 02 had numerous problems, including the intake manifold gasket which went twice. The 02 also had problems with the transaxle twice, some other gasket failure that resulted in all of the coolant dumping on the road and a slew of other things. Everything under GM warranty or 'good will.' I bailed on the lease and signed up for an '04. The 04 was fine.

Ive seen about one 3.1L intake leak to about 10 3.4L intakes. I am a GM service technician, and routinely repair these 3.4L engines. On these engines, you MUST USE A TORQUE WRENCH on the intake bolts. Failure to do so will cause it to fail again in short order. Almost all of these engines seep a little bit through these gaskets, but puddles of coolant in the valley means its time to fix it. Ignoring the problem will cause the head gaskets to fail soon after and possibly complete engine failure. If it needs intake gaskets, do yourself a favour and have it repaired by a qualified technician. If you go to a backyarder or someone who is not an AUTOMOTIVE technician (not a heavy duty mechanic, millwright, welder, etc) and your engine goes boom, suddenly he doesnt know you, and your out $3000 for a new engine install.