Aviator

Well here's the problem, the heat in my 89 S2 isn't working. The climate control works as promised otherwise; the AC blows cold and mixes with fresh air whenever it feels necessary. Meaning, that the mixing control between AC air and external air works fine.

So short of tearing apart the entire HVAC unit, I'm wondering if anyone else has encountered a similar problem. I'm thinking it's either the heater control valve, the mixing flap for the hot air, or the heat exchanger. The hot water hoses from the engine block back to the firewall look fine, and today I'm going to pull the cover and check out the heater core. However, with all the valves and such, if anyone has a suggestion it could save a lot of trouble.

Right now I'm prepping my new car for the move to Wyoming in a week. New, struts, brakes on all corners, ebrakes, oil change, coolant flush, rear hatch leak fix, new cv joints, wiper blades, shifter bushing, sunroof gear fix. If it ain't broke, look closer. All in all, I got what I paid for and aside from these little maintenance issues it's a damn clean car.

It's tough seeing my baby up on jack stands, but she's going to be really sweet when finished. Monday appointment for a four wheel alignment and we're ready to go. Thanks for any help into the heater issue, I greatly appreciate it! Wyoming gets really cold!

JayVee

The heater control valve (near the firewall) should move when the climate control temp **** is turned from full off to full on. Is this happening?

Van

Trade with someone in texas or florida who's AC doesn't work...

inactiveuser92616

its pretty easy to see if the heater valve is working. Look on the backside of the engine, easiest from the driver side. Look at the position of the arm on the valve. Now turn the heat on full and look at the valve. Your problem could be as simple as the vacuum hose having fallen off of the valve.

hderr

Aviator, sent you a PM.

Hank

Aviator

Thanks for the suggestions, I'm going to figure this out tomorrow I'll keep you updated. Friday the UPS man brigs new rear rotors, e brake shoes, and bump stops then the girl is getting buttoned up. Hopefully, the heater will become clear. I want to start breaking into the interior, I think new carpets, and perhaps a wild dash are in order.

Anyone seen alcantra? Would make great door panels too....hmm. There goes this years disposable income.

Aviator

Alright listers,

Well I finally got to see if the heater control valve works, and it does. I was checking the valve that is located right behind the water pump on the line to the firewall for the heater core, the return line goes right into the back driver's side of the block, no valve that I could discern.

In the mean time all the brakes and the front struts have been replaced, and of course that went exactly as planned...hence the delay in getting to the cabin heat.

Coolant levels are fine, just flushed and replaced the fluid, it seems that the heater core lines are getting nice and hot, just no hot air coming from the vents. This leads me to suspect that in the HVAC system the air mixture door for the hot air is not opening. I know that little rod clip can often break leading to perminate heat, would manually causing the same position do the trick in the short term for me until the root problem is identified?

So I have vacuum pressure in the heating system, does anyone know how the heater control door is opened, vacuum, electric motor, or servo? And if so, any tips on replacing?

As always a big thanks to the fellow renn members

Coming soon will be my tirade, I mean DIY, on how to replace the front struts and how to find out that your emergency break cable is broken, not out of adjustment.

-Aviator

Aviator

Well, after getting a four wheel alignment today I decided to take her on the highway for a stretch to check her out. It's a cool day so I kept the windows down and the roof open, and for grins I decided to cycle the heater. Low and behold after about 4 on/off cycles...heat! No idea why, but it works now.

944, got to love it.