Airflite40

The first snag with my new 951.

The 951 was a little low on coolant, so I topped it off the other day, no leaks, checked oil etc.

I left the reservoir cap off and started the car and turned the heat to full on to get the coolant moving and circulate. I put the cap on after like 30 seconds.

Everything was fine, later that evening went for a drive and all of a sudden I had no A/C, heat, nothing.
I would turn the fan speed **** and it did absolutely nothing. I could turn on the A/C and hear the compressor click on, the engine fans were running fine, so the control unit wasn't broken.

I left it alone and the next day the fan speed **** was working again, everything seemed good....until the car warmed up, and I have heat blowing out of the vents, no matter if they are on/off.
If I turn on the A/C I get super cold air cycled with blasts of HOT air.

I figure the heater control valve is stuck in the open position, since this is a florida car so who knows when the heat was actually last used.
I checked the clip under the dash that also fails per clarks-garage and it was NOT broken.

SO, I know what the damn HCV looks like, but I can't seem to get to it. If I could just push it back closed that would make me happy until I pull off the intake in a couple weeks and do a tune up.
Is there any way to reach it with the intake on???

Airflite40

bump too meach reading??

jfeid

Mine was stuck last year. The only way I could get it to shut-off the heat was to run it at full heat for a couple of minutes after the engine warmed up (selected from your dash) and then shut it off at the dash. If this did not work, I kept repeating it until it did shut off. It would always shut off sometimes it took a few cycles. I am not sure how the valve works with the dash controls since it is activated by the vacuum system in the dash. It would reset itself to full heat almost every time I started the car.

After a month, I broke down and replaced the valve and the hoses around the valve. You are better off replacing the hoses since leaving them on and just replacing the valve seems impossible. Plus with a 20 year old car it doesn't hurt to replace these heater hoses anyway. You can get to it, but it requires removing some of the hardware that holds the reference sensor connections and a skinned knuckle or two. Be careful when you cut the hoses (to remove them since you are not going to keep them) at the connections to the heater core in the firewall and from the engine tube to the valve. JF 86 951

Glen Watkins

Mine gets stuck occasionally as well... cycling the heat on and off usually sorts it out.

tifosiman

FYI I had a problem once when the heat was on all of the time, and the clip wasn't broken. I replaced the HCV, and still constant heat. Finally I replaced the climate control unit and that solved the problem.

Airflite40

thanks guys I'll try cycling the heat

Airflite40

well, cycling the heat on off seemed to do the trick. I have cold a/c again and no more heat all the time!!
Thanks guys.

Basically what I did was when the car warmed up, I turned the temp all the way up, and turned the fans to 4.
Then after 15 seconds, I turned the temp all the way to cold and I could hear the air stop for a second, switch, and start blowing lukewarm air.
Then I turned it back up to hot, then back to cold again.
Next I hit the A/C button, and all was good! steady cold air again.

Toolmaster

If you can get to the valve, a little spray silicon in the vacuum hose should do the trick to solve this on a longer lasting basis... Assuming the valve isn't leaking of course.

Good luck!