 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Saab Cars / September 2005Lack of Heat C900
My 85' C900 Turbo had a problem with the heater control valve being stuck. I replaced this unit with a new one, and was expecting hot air when I turned the switch to hot, and the car was able to warm up a bit. Unfortunately, I'm getting sort of a luke-warm kind of air, and was wondering why that may be. There is no shortage of air flow (although the air stops flowing when the selector is in some positions) Also, the coolant is heating up to temp, the thermo is opening up(and I'm pretty sure the air is bled out of the system too) Does anyone have an idea what this is? I personally think this could be a problem with the heater core. If it's not, what else should I check? I had a problem like this with my full size GMC van last year and it turned out to be a low coolant level.(but the coolant is filled in this one) Also.. can someone tell me why the fan motor runs in some air distribution positions and not in others? I'd like to get these things fixed asap before winter is upon me, and I'm w/o my SAAB! Thank you much! -Larry > My 85' C900 Turbo had a problem with the heater control valve being stuck. > I replaced this unit with a new one, and was expecting hot air when I turned [quoted text clipped - 18 lines] > Thank you much! > -Larry Did you get a kink in the hose anywhere? Also are you sure the connecting rod from the heater knob to the valve behind the dash is connected? > (and I'm pretty sure the air > is bled out of the system too) Why are you sure? What did you do to bleed air out of the heater core? > Does anyone have an idea what this is? I personally think this could be a > problem with the heater core. Most likely air in the heater core. > Also.. can someone tell me why the fan motor runs in some air distribution > positions and not in others? It is meant to do that.  SignatureGrunff > My 85' C900 Turbo had a problem with the heater control valve being stuck. > I replaced this unit with a new one, and was expecting hot air when I turned > the switch to hot, and the car was able to warm up a bit. Did you get the linkage rod back onto the valve? You can check through the left speaker grille in the dash. Dave Yeah, I put it on there myself, and turned it up and down a good number of times to make sure I had it on right. The selector on the new ones is pretty much idiot proof. It attaches to the control valve one way, and 1 way only... To answer Grunff and James's questions A kink in the hose? I'm pretty sure I didn't get that. I've got pretty decent air flow coming out of the vents. Why are you sure? What did you do to bleed air out of the heater core? I'm not sure. I've never had to bleed air out of a coolant system before. Is bleeding air out of the heater core different than bleeding air out of the coolant system at the thermostat housing? What I did was open up the valve before the thermostat opened, and closed it once i saw some antifreeze flowing out. Initially, I had figured that filling up the coolant system completely would fix my issue, but that hasn't worked either. > Does anyone have an idea what this is? I personally think this could be a > problem with the heater core. Most likely air in the heater core. If that's all it is, wonderful! I just wish I were more in tune with how to fix these things! I can fix computers, build networks, architect email systems, peoplesoft environments, etc. But with cars, I'm semi-adept at best. >> My 85' C900 Turbo had a problem with the heater control valve being >> stuck. [quoted text clipped - 4 lines] > Did you get the linkage rod back onto the valve? You can check through > the left speaker grille in the dash. > Most likely air in the heater core. > > If that's all it is, wonderful! I just wish I were more in tune with how to > fix these things! I can fix computers, build networks, architect email > systems, peoplesoft environments, etc. But with cars, I'm semi-adept at > best. If the valve is definitely open, and you have the correct thermostat, then I'd say it's an air-lock. You can usually fix by revving the engine with the valve on max. If that doesn't do it, then you may need to force beeld the core. You do this by disconnecing both hoses, and connecting a garden hose to the core. Flush it through with plenty of water at high flow, then reconnect the hoses. SignatureGrunff >> Most likely air in the heater core. >> >> If that's all it is, wonderful! I just wish I were more in tune with how >> to fix these things! I can fix computers, build networks, architect >> email systems, peoplesoft environments, etc. But with cars, I'm >> semi-adept at best. > If the valve is definitely open, and you have the correct thermostat, then > I'd say it's an air-lock. I drove it about 10 miles last night, and was driving steadily at about 50-60mph. most of the trip, and that didn't fix anything. I'll try opening the bleeder valve and revving it. The pain is that most of these things take 2 ppl to do. > You can usually fix by revving the engine with the valve on max. If that > doesn't do it, then you may need to force beeld the core. You do this by > disconnecing both hoses, and connecting a garden hose to the core. Flush > it through with plenty of water at high flow, then reconnect the hoses. Grunff; Would a coolant flush & Fill @ my local SAAB dealer take care of this problem? -LC >>> Most likely air in the heater core. >>> [quoted text clipped - 15 lines] >> disconnecing both hoses, and connecting a garden hose to the core. Flush >> it through with plenty of water at high flow, then reconnect the hoses. > Would a coolant flush & Fill @ my local SAAB dealer take care of this > problem? Possibly, but it really depends what the problem is - you need to investigate further. If the revving doesn't work, then you really need to hook up a garden hose to the heater core and flow water through it; this will tell you if the valve is stuck or there is a blockage. SignatureGrunff Grunff, Considering that I just replaced the valve with a brand new one, that's why I initially thought that it most likely might be the heater core. So I think I'll try your test. What will a clear(non-blocked) result look like, and what might one that has some degree(even heavy) blockage look like? Thanks! -LC >> Would a coolant flush & Fill @ my local SAAB dealer take care of this >> problem? [quoted text clipped - 3 lines] > hook up a garden hose to the heater core and flow water through it; this > will tell you if the valve is stuck or there is a blockage. > Considering that I just replaced the valve with a brand new one, that's why > I initially thought that it most likely might be the heater core. Yes, I realise that, but it really could be one of a number of things. The new valve could be blocked. The core itself could have a blockage. > So I think I'll try your test. What will a clear(non-blocked) result look > like, and what might one that has some degree(even heavy) blockage look > like? If it's clear, it'll flow very well. If there's much of a blockage, you will get reduced flow. With the water running, turn the heat up + down. The flow should increase and decrease accordingly. Let us know the results. SignatureGrunff I tried this... looks to be pretty clear. The core was in near pristine condition when I took it out the other day. Once I put the water on, there was about a 2-3 second delay till I saw fluid coming out of the bottom port. After that, it took about 30 seconds to clear all the antifreeze out of the core, and flowed well throughout the test, and I put the hose up to both ports, and water flowed well going either direction. I think I got it bled correctly now.. I shut the screw when the fans were running. We'll see on the temperature of the cabin air tonight once the ambient temp outside goes down. I didn't turn the heat up and down.. It was set to full heat the whole test. >> Considering that I just replaced the valve with a brand new one, that's >> why I initially thought that it most likely might be the heater core. [quoted text clipped - 13 lines] > > Let us know the results. > I tried this... looks to be pretty clear. The core was in near pristine > condition when I took it out the other day. [quoted text clipped - 12 lines] > I didn't turn the heat up and down.. It was set to full heat the whole > test. Well, sounds like your core is clear, and full of water. I'd hook it back up, run the engine for a while and see what happens - if you still don't get heat, then I'd start looking at the thermostat. SignatureGrunff Okay.. I'll have to try that tonight and get back with you. As far as the thermostat goes.. the engine isn't overheating, it's opening up properly, etc. Is there a saab-specific reason you think this could be the culprit? >> I tried this... looks to be pretty clear. The core was in near pristine >> condition when I took it out the other day. [quoted text clipped - 16 lines] > up, run the engine for a while and see what happens - if you still don't > get heat, then I'd start looking at the thermostat. > Okay.. I'll have to try that tonight and get back with you. As far as the > thermostat goes.. the engine isn't overheating, it's opening up properly, > etc. Is there a saab-specific reason you think this could be the culprit? Yes, your engine uses a magical 3 position 'stat. Cold: coolant circulates through block + heater core, not rad. Hot: coolant circulates through block, heater core + rad Too hot: coolant circulates through block + rad The idea being if the engine is too hot, you don't waste precious time circulating the coolant through the heater core. When your engine is at working temp, do the core in/out hoses get hot? As hot as the rad top hose? SignatureGrunff Yes, both the top and bottom hoses get hot. Are they as hot as the top radiator hose, of that I am not sure.. I'll have to check on that one. Is it possible that it's only working on the cold and too hot positions, and not the hot? >> Okay.. I'll have to try that tonight and get back with you. As far as >> the thermostat goes.. the engine isn't overheating, it's opening up [quoted text clipped - 12 lines] > When your engine is at working temp, do the core in/out hoses get hot? As > hot as the rad top hose? > Yes, both the top and bottom hoses get hot. Are they as hot as the top > radiator hose, of that I am not sure.. I'll have to check on that one. > Is it possible that it's only working on the cold and too hot positions, and > not the hot? It's very possible, yes. Where did you get the stat from? What's the heat situation now that you've flushed the core? Still the same? SignatureGrunff The top hose, and the core hoses both get hot... they're not exactly the same temp... the top radiator hose is a little hotter, but not much. Heat inside the car is still the same.. luke-warm. The stat was in the car when I purchased it in January, so I have no idea. Looks like I need to try replacing this thing. >> Yes, both the top and bottom hoses get hot. Are they as hot as the top >> radiator hose, of that I am not sure.. I'll have to check on that one. [quoted text clipped - 5 lines] > What's the heat situation now that you've flushed the core? Still the > same? > The top hose, and the core hoses both get hot... they're not exactly the > same temp... the top radiator hose is a little hotter, but not much. Heat > inside the car is still the same.. luke-warm. > The stat was in the car when I purchased it in January, so I have no idea. > Looks like I need to try replacing this thing. It's worth replacing the stat every 2-3 years as a matter of course anyway. I don't know what the climate is like where you are, but if it's hot, it's worth getting a lower temp stat than the standard - 83C is a good medium. SignatureGrunff >The top hose, and the core hoses both get hot... they're not exactly the >same temp... the top radiator hose is a little hotter, but not much. Heat >inside the car is still the same.. luke-warm. >The stat was in the car when I purchased it in January, so I have no idea. >Looks like I need to try replacing this thing. Perhaps. The hose connecting to the top port on the back of the heater control valve should by the one that's connected to the water pump. If you have rust-like gunk accumulating throughout the coolant system giving it a very good flush should help, but it depends how well the coolant mix has been maintained and how often the previous owner(s) checked it. I did a heater valve replacement on my 1985 900i some time back - check "http://lios.apana.org.au/~c900/heatervalve.html" if you'd like to see what I did. A few people have offered some extra tips and advice which I still need to incorporate into the page. Regards, Craig. SignatureCraig's Saab C900 Page --> http://lios.apana.org.au/~c900 Sydney, NSW Australia Craig's Saab C900 Workshop -- For all Saab C900 Enthusiasts world-wide! http://www.saab900classic.net http://www.saab900.org c900@lios.apana.org.au Come and explore our site, and check out our web-forums, mailing list, etc. Other possibility is the water pump. If the pump is deteriorated (and they do sometimes), the flow will be enough to maintain circulation through the engine, but outposts like the heater matrix suffer from reduced water flow. Not sure how you can test it, but they're not that expensive to replace. Steve >I tried this... looks to be pretty clear. The core was in near pristine >condition when I took it out the other day. [quoted text clipped - 30 lines] >> >> Let us know the results. The fan should be running in all posistions except 0. In <=> it goes on a "4th" speed. So what would make the fan stop in positions other than <=>? > The fan should be running in all posistions except 0. In <=> it goes on > a "4th" speed. a blown resistor for speed 1 2 or 3 I would think. However, the fan is very quiet at speed 1 and to a lesser extent 2. If you move the fan speed control higher you should see a difference, except in the big <=> which is always a speed "4". see if you feel air moving in when the car is stationary in speed 1. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.