99 Grand Am GT Coolant Leak

[dmallett]

My 99 Grand AM has been leaking coolant for some time. After reading other threads on the site I agree that it was probably the intake manifold. I took it to a local repair shop and they agreed. I picked the car up after having it repaired, and it overheated on the way home. Coolant was pouring from the reservior overflow. The shop felt that there may have been an air bubble in the line, or that the thermostat may have been stuck. They changed the thermostat, refilled the coolant, and bled the lines. After that I continued to smell coolant and would see small amounts on the ground. The reservoir would remain empty, and if I added any fluid it pours from the overflow after the engine is warm leaving the reservior empty. I took it back and they said that there was a small leak from the waterpump. I was a little surprised by this, but was so fed up with dealing with it that I agreed to have it fixed. After this, it seemed to be fixed for a week or so. Then it started leaking slowly again. The fluid seems to be coming from the overflow. There is a hissing sound coming from the reservoir as well after turning the car off. Then the other day it overheaded on me. The fluid was dry. I added more fluid, bled the lines, added more fluid once the engine block filled. 2 days later the low coolant light is back on and I can smell fluid. I can not see anywhere on the engine where coolant is coming from other than the overflow.

What would cause fluid to pour out of the reservoir when the levels are low to begin with? Is this a sign of an improperly repaired manifold gasket? Please help.

[xeroinfinity]

Had the same troubles with my 99 GA. What I found was that if you over fill the reservior it blows the excess out but it has a syphon effect. What I mean is it just keeps spewing out coolant. I bent the over flow hose up a little to keep it from syphoning out coolant. Air pockets will over heat the engine and you could very well blow a gasket in doing so. When filling the coolant did you run the heater? You should because air traps in there easily and will cause flow trouble.

Even with low coolant when the engine gets hot it takes less coolant to fill the motor so the extra coolant starts back flowing. Running the shit out of the car can make it overflow, then the next day it would be low and I'd get the low coolant light(until it warmed up).

Somethinng else to try is take the reservior off and clean it with some soap and water, may be something cloging up a hose or inlet/outlet. Also look at the ends of the radiator for cracks(they are plastic) this is also commen for this type of radiator to leak there. Hope this helps explain everthing. Oh ya Welcome to AF.

[dmallett]

Thanks for the advice and the welcome. I did not run the heater while filling the fluid. I'll give that a try as well as cleanign the reservior tank. This has been a frustrating ordeal. Hopefully this helps. Thanks

[xeroinfinity]

Originally Posted by dmallett

Thanks for the advice and the welcome. I did not run the heater while filling the fluid. I'll give that a try as well as cleanign the reservior tank. This has been a frustrating ordeal. Hopefully this helps. Thanks

Run the heater for sure! air traped wont allow enough coolant into the system.

[tehman]

i just replaced a little plastic coupler on my 99 SE, it was a slow leak, but a leak nonetheless. its where the heater core hoses attatch to the engine pipes. it was very brittle..broke off in the hose. its a pain in the ass, but might be worth checking out. you should know if its leaking right away if the back of your engine is orange from coolant.