Hey guys,

LIke the title states, my parents have a 1999 Alero with roughly 155,000 miles on it, and recently it stopped blowing heat. I am familiar with bleeding the cooling system, but wasnt sure if the 3400 has a way of doing this..Is there a way? I know that generally air in the cooling system results in no heat as well as occassional overheating issues. As far as I know, the car has yet to overheat.....

So open to suggestions,,,Bleeding cooling system? Heater core?

Thanks!

best way IMPO to start is by if there is an air pocket remove it.How i do this is start the car let it run for 2 3 minutes.. then shut it off jack the car up as high as possible without flipping it lol put it on a safety/jack stand on the side that the radiator fill neck is on and open/take the cap off and start it then let it run like that and it will gurgle out any air pockets that are present...
Heater core..Not sure on the aleros but usually the plastic box that surrounds them has a evap hose
Its just a outlet for moisture if the heater core is bad it usually will be wet...Also you can wait untill the coolant is warm and touch both heater core hoses and see if they are both warm

One more thing if it is a thermostat suspected also..after being at op temp touch the upper and lower rad hose if one is cold and the other is hot your thermo is bad or it has more major issues

Warning THE COOLING SYSTEM CAN BE VERY HOT SO BE CAREFUL TOUCHING HOSES OR ANYTHING THAT HAS TO DO WITH THE COOLING SYSTEM.Pleas do not reach for the lower hose with the car running as the fan is electric and could kick on at anytime

If you do need to remove air from the cooling system, there should be a bleeder screw on top of the thermostat housing. Loosen that a bit and then start the engine to work out the air bubbles with minimal mess.

If that doesn't fix your problem, and you've touched the hoses that you've been told to touch, test the air mix actuator.

Oh yeah i did not know the 3400 had an air bleeder screw.....Thanks for adding that collin

Most engines do; Yonkerse'* mileage may vary.

The 3800 does, at least.

neither my l27 or l67 had one....mustve been the oddballs lol..

Thanks for replying with suggestions. I was thinking there may be a bleeder valve on the 3400....but I'm really most familiar with the 3800.

I will be home the next few days and will do the recommended checks to determine the issue!

Thanks!