I noticed a small puddle of coolant in the driveway a couple days ago. When I got out today I smelt antifreeze really bad and notice it dripping from the bottom in a couple spots. I popped the hood and it seemed like it was coming from the front of the motor. I checked my coolant level it was fine as well as the oils which looked a good color. So if you have any thoughts or could help me out I'd appreciate it.

Three things:
#1 LIM gasket bad
#2 hairline crack on top right side of edge of radiator
# 3 water pump starting to go

All three are super common problems with the the 4.3L which is common engine for the Sonoma (assuming you have 4,3L)

How many miles on your Sonoma?

Which coolant level did you check? Radiator or overflow bottle?

Taking a "morning" look at your post, I am guessing you have a hairline crack in the plastic part of your radiator, on the top, right side. The reason you see only a little bit of coolant is that it only leaks when the engine is hot; and since the hairline crack is at the top. You can check for this two ways (1) check for wetness at the top of the radiator immediately after a long trip (2) look for wetness under the hood near the front on the frame, block etc. The wetness may look oil like, as the coolant slowly combines with the oil and dirt on the frame and engine and looks like thin oil.

We need to know your mileage and if you have ever changed your LIM gasket. You will be replacing the LIM gasket as your 4.3L engine approaches 70k plus miles. Finally, the water pumps also fail on the 4.3L, a new OEM pump runs about $40.

Assuming the LIM gasket is original and the radiator is the source of the leak, I would consider replacing the LIM gasket, radiator and water pump both as a repair and as a preventative measure. Total parts cost (Delphi radiator $100, FELPRO LIM Gasket set $60, AC DELCO water pump $40. All parts from rockauto.com . $200 in parts (plus your labor) and coolant.

All the above parts are interconnected. Changing them out at the same time will actually save you time and money in the long run.

146,000

I'd guess your LIM gasket has already been replaced, so makes a case that the radiator is the more likely source of the leak.

A cooling system pressure test is a sure way to pinpoint, but you may have more than one leak (radiator and LIM gasket as an example, both may have issues).

lower intake manifold possibly leaking in the back. i understand that it may have already been replaced.. but with what? the same problem plastic gasket that came with the vehicle from the manufacturer. now with the new style gaskets you should have no problems