95 Grand Am SE 3.1 Coolant Leak

12-11-2011, 07:27 PM
I've been using this site for a while and usually find my problems already posted but now I have one that I haven't been able to find a thread on.

My car (176k mileage) has been losing coolant at a small rate (low coolant light would come on maybe once every 2 weeks) and I would top off the reservoir and I'd be good. I would never actually see it leak out anywhere, so I always figured the head gasket had a slight leak.

Last Friday, it starts losing coolant at a much faster rate. I went to work in the morning and the Low Coolant light came on. So after work I topped it off. Now I'm used to it taking a little while for the light to go away, so I just went on my way and 10 minutes later, at the gas station, I see lots of water coming out under the passenger side/firewall area.

I finally got the car home and upon further inspection, I see the water is coming out of the passenger side end of the rear cylinder head. It looks as if it's coming from what looks like a small freeze plug on the end of the head. I don't have a cooling system pressure tester but I ran the engine with a hose in the reservoir until I spotted the leak. After that, I had to remove the alternator to be sure that's where it was coming from. The freeze plug and the area around it have a rusty discoloration.

Is it possible to replace the plug with out removing the heads? How do I know for sure if I need a new head gasket? I never got any coolant in the oil or vice versa. If I need head gasket(s), what else should be done while I'm in there? What should be done to the heads while they're off (I would take them to a machine shop if they needed work)? The water pump was replaced about 20k miles ago. I guess the timing chain would be wise to fix while in there. Anything else?

On another note, I am having a hell of a time getting at the bottom bolt on the thermostat housing. Any tricks to that?

I'd appreciate any help or guidance in this matter. I'm fairly competant at working on my car, it's just so much easier when you have the help of people that have done it before.

Thanks in advance,

12-11-2011, 07:29 PM

12-11-2011, 07:30 PM

Tech II
12-12-2011, 03:03 PM
Hard to tell from that picture, but I'm thinking lower intake gasket...

01-11-2012, 12:32 PM
Hard to tell from that picture, but I'm thinking lower intake gasket...

You were correct. Turned out to be the LIM gasket with the added plus of the freeze plug needing replacement.

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