oil in water

I just got a 95 lumina APV 3800 with what was believed to be a rear head gasket failure but now im starting to wonder. It was leaking coolant badly from the back of the block and also there was a little oil in the water but no moisture in the oil. After I pulled the alt. I found a plastic fitting for a water line on the block broken (must be the cause of the water leak). My question being can oil get into the water from just a LIM gasket failure or should I just replace all of it since i'm already there? Thanks
Devon in MI

Are you sure the oil in hte water is motor oil? There have been reported cases of transmission oil leaking through the radiator cooler...otherwise lower intake manifold gasket failure is a known occurrence with the 3800. Head gasket failures are very rare on the 3800.

OK mabye I wont go as far as the head gasket - the engine runs great but the previous owner told me alot of oil was leaking off the back of the block, but I believe it was oil in the water leaking from that bypass hose fitting. Will it be obvious when I pull the intake if its the culprit? And is there a way to test that radiator? Thanks
Devon MI

A head gasket failure would be accompanied by several or all of these symptoms: fluctuating temp indicator, overheating, poor heater performance and steam venting the radiator. As for the transmission cooler and LIM gasket I have not experienced those but I know loosing coolant from the back of the engine is a classic symptom. Others will surely come in this thread and comment. More have talked about this in the Bonneville forum...but there are more occurrences with the series 2 3800..
http://www.automotiveforums.com/vbulletin/showthread.php?t=283650

which I am not sure if it was actually used in the Transport/APV following its introduction in 1995 in other GM cars...1995 was the last year the 3800 was used in the Transport/APV
If you dare disconnecting the cooler lines from the radiator.....I'd block one port and use compressed air in the other to see if bubbles come through the coolant from the top of the radiator......The suggestion about the radiatior is "do not forget to check that out also, just in case"....; although this event has been reported, I see that as a low probability..unless you have already determined the "oil" was transmission type...

Well, ill start digging into it tonight after I get home from work. Looked on car-parts.com and found a radiator locally for $50. I hope thats the problem so I dont have to start tearing into the engine.

Wll I just got homw and relised that I have tranny lines and what appears to be oil lines running to the radiator. I cant tell if the oil in the radiator is from the tranny or engine.

There are no motor oil lines to or around the radiator. But there are lines from the power steering that go to a loop of piping tied to the lower frame just under the radiator.

I see that now -- trans cooler on both sides.