92 Sunbird losing coolant

Hi everyone, new member here and am having a problem with my 92 Sunbird with a 3.1 engine,170,00 original kilometers, automatic transmission. I recently bought this car and at the time it had been sitting for over a year, car had been in an accident and the front passenger's side had been damaged. When i bought this project i checked all fluids popped in a new battery and it fired right up, although car had been damaged on the front passenger's side it ran and steered quite well so instead of towing it home, i put on a permit and drove it some 70 miles to my house, with zero problems.
The car has sat for a few months in my backyard and now i am trying to restore it and make it roadworthy, i have removed the damaged fender and front plastic bumper as well as the hood (all were damaged) and replaced the fuel vapor cannister which was damaged and mounted another i pulled from a local auto wrecker. All the parts i need are currently available at this auto wrecker and are even the right colour...so all should be good right?
Wrong, when i moved the car into the garage to start working on it i experienced coolant loss, the car never overheated and was immediatly shut off, after i removed the damaged parts, i then topped up the coolant overflow with water and started the car. Once again i began to lose coolant immediatly and from where i was looking with my trouble light it appears to be coming from the back of the engine closest to the dash.
I need to know if the 3.1 has a hose or frost plug back there that might be causing this problem, my Haynes manual gives very little detail on the 3.1 engine and i am currently undecided weither to continue with this rebuild if the problem is a rear seal or something equally extreme...any thoughts on this problem would be greatly appreciated, sincerely Wiley1803.
P.S. I would really like to find an exploded view of the 3.1 engine so i can better decide what is actually causing this problem and how i should tackle it, so if anybody knows where i can find this it would help immensely....thanks again.

Since you're in Canada, I suspect this car has the engine block heater in it. It takes the place of one of the rear freeze plugs, and is common to leak on older examples. That is the only thing other than the heater core drain, located in the firewall just behind the engine toward the pasenger side. Normally, when the heater core is leaking, you'll either get a sweet smell inside the car, or steam on the windshield. However, since you're not letting the car get warmed up, you may not get the smell.

Since you're in Canada, I suspect this car has the engine block heater in it. It takes the place of one of the rear freeze plugs, and is common to leak on older examples. That is the only thing other than the heater core drain, located in the firewall just behind the engine toward the pasenger side. Normally, when the heater core is leaking, you'll either get a sweet smell inside the car, or steam on the windshield. However, since you're not letting the car get warmed up, you may not get the smell.
Thanks for your input richtazz, it is appreciated.

Hi everyone, new member here and am having a problem with my 92 Sunbird with a 3.1 engine,170,00 original kilometers, automatic transmission. I recently bought this car and at the time it had been sitting for over a year, car had been in an accident and the front passenger's side had been damaged. When i bought this project i checked all fluids popped in a new battery and it fired right up, although car had been damaged on the front passenger's side it ran and steered quite well so instead of towing it home, i put on a permit and drove it some 70 miles to my house, with zero problems.
The car has sat for a few months in my backyard and now i am trying to restore it and make it roadworthy, i have removed the damaged fender and front plastic bumper as well as the hood (all were damaged) and replaced the fuel vapor cannister which was damaged and mounted another i pulled from a local auto wrecker. All the parts i need are currently available at this auto wrecker and are even the right colour...so all should be good right?
Wrong, when i moved the car into the garage to start working on it i experienced coolant loss, the car never overheated and was immediatly shut off, after i removed the damaged parts, i then topped up the coolant overflow with water and started the car. Once again i began to lose coolant immediatly and from where i was looking with my trouble light it appears to be coming from the back of the engine closest to the dash.
I need to know if the 3.1 has a hose or frost plug back there that might be causing this problem, my Haynes manual gives very little detail on the 3.1 engine and i am currently undecided weither to continue with this rebuild if the problem is a rear seal or something equally extreme...any thoughts on this problem would be greatly appreciated, sincerely Wiley1803.
P.S. I would really like to find an exploded view of the 3.1 engine so i can better decide what is actually causing this problem and how i should tackle it, so if anybody knows where i can find this it would help immensely....thanks again.
I have found the source of the leaking coolant but am still not sure what i am dealing with (possibly heater core hose ,but unsure), i have a few pictures showing first the general location and then a more detailed look at the actual problem area but am currently unable to post attachments. If anyone can tell me how i can post these pics for viewing i think it would help out alot...thank you.

I have further isolated the problem and found it to be a drain plug that is located behind the engine,it seems there are two hoses running to the heater core and right beside these two hoses is a small plastic plug which sticks out of the car facing the back of the engine (possibly an overflow).
Everytime i put water in the coolant resovoir to start the car, water runs out this plug immediatly and on startup it shoots out until the low coolant light comes on inside the vehicle, any ideas as to what is causing this?
I am a little confused as to why this plug or drain will allow the coolant to escape so easily, any help on this matter would be welcomed.

sincerely Wiley1803.

if the car has been sitting for a while, hoses could be plugged. see if thier is a way to replace this plug and try it out.

if the car has been sitting for a while, hoses could be plugged. see if thier is a way to replace this plug and try it out.
Thanks for your input and if i follow you correctly you are saying heater core hoses may be plugged therefore diverting the coolant to the plug i mentioned earlier which acts as a overflow for the coolant circulating in the car's cooling system.
I have wondered this as well and think i will end up replacing heater core and hoses but am currently reading more before taking this action...thank you again.

same problem here :(

When I bypassed the heater core hoses, all leaking stopped. Therefore, I suspect a leaking heater core. I am gonna start wrenching on mine today to see if that is the problem.

The 3.1s have a quick disconnect fitting on the coolant tube running to the throttle body (on the back of the engine) This fitting is notorious for rusting out and causing fluid loss.....