1990 Bonneville SE

My car doesn't produce enough hot air through the vents in the winter.
One mechanic suggested I flush the heater core out, while a second and third mechanic said to change the thermostat to a 195 for the winter.

Any suggestions?
PS I have already purchased a the 195 degree thermostat along with the o-ring. I read somewhere on here that a gasket or seal is also necessary? If I decide to go with the replacement of the thermostat to solve the heating issue, what is the proper way to install it?

thanks

Change the thermostat. You can use a bead of RTV (silicone, but get the right stuff) to form a gasket for the thermostat housing if you can't buy a gasket.

When your car is up to operating temperature, what is the reading on the coolant temperature gage?

This should give you a good idea on what you need to do to change the thermostat. https://www.gmforum.com/t278803/

Do you have a lot of air blowing? Or is it just blowing cool.

Thanks for the responses.
The temperature gauge is at the normal half way mark when the car is warmed up and the vents are blowing strong. I the temp gauge indicates it is operating at normal temps, is it still a thermostat issue?

Are there markings on your gage so you could tell us what the temp is? Can you post a picture of your gage at full operating temp?

The reason I told you to change your thermostat is because it is so cheap and easy to change, it is worth doing it just to understand if it is the issue or not. If the problem is solved, great, if not, you have not invested a lot of time and money.

This could be the air mix actuator. Simply not adding much if any hot air.

Thanks, I read the link on installing a new thermostat. It seems pretty straight forward. The only question is how do I know if there is air in the system and I need to bleed it? It mentions the need to bleed out the air bubbles, if necessary.

Danthurs is right in that it could be the air mix actuator, but since you already have the thermostat and it is an easy install, I would still install it. Even if the thermostat is not the problem it will at least rule that out.

I'm not sure our cars have a bleeder for air in the cooling system. I fill mine, start the engine with the rad cap off and add more fluid as the car comes up to temperature. Put the radiator cap back on, drive it until up to full operating temperature and with the heat turned on full. Once the car has cooled down (DO NOT OPEN THE CAP WHEN THE COOLANT IS HOT) remove the rad cap and top up if required. Make sure the overflow bottle is at the correct level.

I hope it'* the thermostat though. Oh yeah, I just wanted to know and how every necessary part before I begin. All I need is a thermostat and the o-ring right? Sorry for the dumb question that may seem obvious to those mechanically inclined. I think I read somewhere that a gasket may be needed?

I've tried to remove the thermostat housing twice this past week and it seems stuck. I removed the engine cover with the 3800 on it, removed a bolt and tried to remove the housing but it doesn't budge.
I'm I doing something wrong? Are there two bolts? Do I have to remove something else besides the one bolt?