Yesterday upon squeezing my upper rad. hose i could hear some bubbling type noises comming from the back of the block. I understand this is probably not too good. Any ideas would be awesome. I searched already and didnt come up with anything really straight forward.

 

The only coolant lines on the back of the engine I can think of are the input/output lines for the heater core. One runs to the back of the block and the other to the therostat housing I believe.

 

haha i hate those lines, they always have coolant in them!!

there's also the water pipe

 

AH yes I forgot about that. Maybe a bad Oring? You will have to do some looking around.