Christopherb611

This is my first post here and I'm not exactly sure how everything works but I appreciate any input at all because I am stumped. I am trying to flush my coolant as I bought the car a little over a year ago and am not sure the last time it was changed. So I watched the video thinking pretty standard procedure blah blah. I go to turn my heat on with the key to the 2nd position and ambient air comes out. I checked the heater control valve and it doesn't move at all when switching to AC or heat. The lever to the heater control valve moves freely when cable is detached and when i manually pull it open i can feel heat on both sides of the hoses. I saw billman chime in to one of the threads talking about the air mix blend motor or one of the cables became disconnected. I'm not sure about the possibilities of an air bubble in the system or the thermostat but the car runs fine and doesn't overheat at all. I've never taken a dash apart and honestly am intimidated at the thought of it and was wondering if there is anything someone can suggest me look into before doing so or flushing the coolant and adding new fluid in and hoping the culprit was an air bubble. Also not sure if I can even do a proper coolant flush and change considering the heater control valve doesn't move. Again any input is appreciated

Car Analogy

The problem with an air bubble is its a ticking time bomb, no way to know when it'll go off. It'll seem fine, then one day overheat out of the blue, destroying engine.

So saying it seems fine doesn't overheat isn't meaningful. Maybe it is fine, but the fact it hasn't overheated yet isn't a fact that helps prove that.

Did you at least raise front of car, park on hill whatever? Did you cycle both bleeder screws multiple times, until no initial air? Did you use a Lisle type funnel, and let it idle long time, then get some revs in?

I would be wary of how fully bleed can be without heater valve operating. But if you didn't do all those things above, you have more to worry about.

Christopherb611

I haven't tried those methods of bleeding. I have yet to bleed the car because the heat didnt then started investigating and noticed the issue with the heater control valve not opening or closing. I'm not sure if there is any air in the system at all that's the problem. I guess I should flush it regardless to try to eliminate an air bubble being a variable

dwb993

These cars are notorious for being finicky with a coolant bleed. Read through Billman's bleed procedure thoroughly. His writeup is one of the more complete I have seen. Go here: https://s2000.club/installguides.php and under the "Engine/Chassis/Trans" section, click the link for "Draining and Filling Coolant". Follow those instructions. Be sure to read through them BEFORE actually doing anything under the hood, as there is a lot of info there.

Christopherb611

Thank you so much, all of that information is super informative. Only question I have is since the heater control valve doesn't move should I manually pull it open during the bleeding/ filling process?

dwb993

I can't answer that with certainty. Sorry.

Christopherb611

where's Das billman God when you need him lol, i appreciate all your help

Chuck S

It shouldn't. It should move when you turn the temperature dial either way -- makes no difference if AC is running or not. Yes, you can run the heat full blast while the AC is running. (Or did you mis-type this?)

Regardless you can manually put the valve in max heat to bleed the system and figure out if something is loose later.

-- Chuck

Christopherb611

yes it was a mis-type, I meant when you adjust the dial between cold and hot. Good to know, just didn't want to inadvertently cause more air bubbles or not have the entire system be flushed if valve was closed when trying to bleed. I'm guessing if heat still doesn't come on after this the air mix control motor is the issue. Thanks again for your response