Mello

I haven't had any heat since I got this car. So everything seems to be working. All *****, flaps, servos, clips etc that I know about. I just can't get a lick of hot air to come out of the heater. It seems that hot water isn't making its way into the heater. The two insulated pipes in the passengers footwell, which I believe are for coolant, don't seem to be getting hot. I've jacked up the front of the car to bleed, but no improvement. I don't even get heat when I really step on the gas, like some people have had with air in the system. Could there be that much air trapped in the heater that coolant can't come through? I was thinking of opening the system at the heater valve, and forcing water through the heating system with a hose or pump. Any suggestions?

AR10

Yup, sounds like air in there. Just keep bleeding out from the
screw on the upper hose outlet. Elevating the front may help.
Try it with engine running. Be careful! It will be hot!

Mello

I did it with the engine running for a long time. It seemed like I was just getting coolant. I kept adding coolant to the tank and letting it bleed. I guess if there's alot of air in the heater, the coolant can't push through, so it just circulates elsewhere as if the heater valve is closed.

Techno Duck

Make sure the vacuum line on the heather control valve is connected and intact. The valve is located by the waterpump on the 16v engines.

marky522

Yeah, sounds like you are having issues with the heater control valve. You wouldnt have that much of an issue with an air bubble.

Mark

Mello

It's not the heater control valve. The valve is designed to fail in heat mode, and I replaced it anyway. It opens and closes as intended. The two flaps under the dash move as intended also.

75ohm

It needs to burp.

nickg

my s2 cab was like that..make sure the water pump is circulating well..it maight be when cold, but not so when hot

Mello

Hey nick!! No heat ever ever ever. I think I'm going to open the bleeder and open the system by the heater valve and force water into the heater itself.

AR10

One possibilty: I have seen heater cores plugged up with radiator
sealer (stop leak). One of the worst is Bar`s Leak if it used in excess.
You can try removing both hoses at the core and force water through
with a hose and maybe with compressed air.

Mello

OK, so I just opened up the cooling system at the hard pipe by the headers. I also opened the bleeder and reservoir cap. I then took a garden hose and forced water into the cooling system towards what I believe goes through the heater core. My goal was to push any air out of the heater core. The water seemed to go in fine, making the level at the reservoir rise, and I believe something came out of the bleeder. I then quickly removed the hose and reclamped at the hard pipe. Then I started the car and bled as usual, topping off the reservoir with coolant. STILL NO HEAT!!! I then rechecked everything. I unclipped the heater flaps and played with them manually. STILL NO HEAT!!! Is there anything I could be missing? The heater valve is new and fine, the water pump was replaced just before I got the car. I can't think of any reason why I can't get hot air. Not even a little bit!

75ohm

Do you have a hot temp at the heater valve? How about at the return line? How about at the water pump to the radiator?

Rock

My girlfriends car has this problem. I bled her coolant system to the maxin. Its not air in the system.

The problem has something to do with one of the relays im thinking, as the control unit works properly.

This is what I did to get her heat. There is a little plastic clip under the drivers that holds a little metal rod. Pull that open, and im almost 100% positive HEAT will blow. Im not sure how to totally fix this, but I clipped it in the summer for her A/C and it worked fine.

Winter came however and she had no heat, so this is what I had to do.


Unless you already tried this.... and thats what you meant by heater flaps lol. Then I DONT KNOW!

Mello

The rods and clips check out fine. The heater control valve feels hot. This is an S2 so the heater control valve is at the front of the engine. The hard pipe by the headers feels hot, but it IS right by the headers so I'm not sure. Down in the passengers footwell are two insulated pipes that I believe are for the coolant to the heater core. Those DONT feel like they're getting hot. Where is the return line?

Clint's 944

Go to autozone or whatever you have up there and get a radiator pressure tester through a free loan a tool. Pressurize the cooling system up to 15 lbs or so and then turn the bleeder screw, if there is air...it will come out.
I do this all the time with my S2 and I never have any problems bleeding it out.

Good luck!