WhiteOut Posted October 11, 2004 Report Share Posted October 11, 2004 Well its finally happened, I had to use the heat this morning and last night going to and from work. While doing so I noticed that it doesn't seem to be working all that well. In fact it took 10-15 minutes of the car being at running temp for the thing to blow anything resembling "heat". The point is this could suck really bad sometime soon if I don't do something about it. My car is a 95' Cutlass with the 3.4 DOHC and I've got the automatic climate control system. So I guess I'm just wondering if this is a clogged or partially clogged heater core or if perhaps this is a climate control system failure. I did a complete coolant system flush at the end of last summer when I got the car and it was pretty nasty looking stuff at the time. The coolant looks pretty good currently, but I've been thinking of flushing it anyways in the interest of preserving the head gaskets as long as possible. So does anyone know if the chemicals meant to clean the cooling system will also take care of any clogs that might be in the heater core? I'm afraid that it could make things worse by disloging something in the system and bottlenecking an already tight spot. I'm not sure what to do at this point, and I'd really rather avoid having to replace the heater core. So, enough rambling...your opinions please. Quote Link to comment Share on other sites More sharing options...
mihela816 Posted October 11, 2004 Report Share Posted October 11, 2004 The outside of the heater core could also be clogged. Quote Link to comment Share on other sites More sharing options...
skiiirt Posted October 11, 2004 Report Share Posted October 11, 2004 Clean the heator core. Also check your climate control diagnostics to be sure it isnt the climate control messing up.. Thats a bitch Quote Link to comment Share on other sites More sharing options...
WhiteOut Posted October 12, 2004 Author Report Share Posted October 12, 2004 The way the car is running warmer than usual is starting to make me think that this could be a thermostat problem as well. If it was stuck open or closed could that cause the heat to malfunction? Quote Link to comment Share on other sites More sharing options...
DOHCRagtopguy Posted October 12, 2004 Report Share Posted October 12, 2004 If your car is warmed up and there's no heat coming from the vents, I'd say it's definitely a thermostat problem. If I was you, I'd pull the stat out, do a real good flush, then replace with a new stat after cleaning. Just my .02 Quote Link to comment Share on other sites More sharing options...
WhiteOut Posted October 12, 2004 Author Report Share Posted October 12, 2004 If your car is warmed up and there's no heat coming from the vents, I'd say it's definitely a thermostat problem. If I was you, I'd pull the stat out, do a real good flush, then replace with a new stat after cleaning. Just my .02 But if thats the case wouldn't that imply that the thermostat is stuck wide open, and that should cause the car to run cooler than normal if I'm not mistaken, yet the temp gauge shows it running slightly hotter than normal. I know these gauges aren't exactly precision instruments, but the thing is pointing to the mark thats after 200 rather than the one before it, which makes me hesitate to that its stuck wide open. I suppose I'll just replace it since its an easy job and see how it goes. Quote Link to comment Share on other sites More sharing options...
Baddflash Posted October 12, 2004 Report Share Posted October 12, 2004 Well it's actually rather easy to check if the thermostat is stuck open or closed without pulling anything apart. If it's open it will circulate at all times and therefore run cooler and take considerably longer (depending on temp of the day) to get up to operating temp. If it's closed the engine will run hotter for sure and unless it's cool enough outside it should overheat. If it's stuck closed when the engine is at temp the hoses going to the rad should still be cool and so should the coolant in the rad. Is there actually air blowing? it's just not hot? It's possible that the little gate in the heater box that switches between cold and hot is not moving properly either because of the CC or cause of another issue after the CC. Hope this makes sense and possibly helps. If not I'm really tired and haven't been able to eat all day, so please just disregard. Quote Link to comment Share on other sites More sharing options...
kcac Posted October 13, 2004 Report Share Posted October 13, 2004 WhiteOut The same symptoms turned up this past spring on my 1995 Cutlass with the 3.4 engine and the automatic climate control system. A cooling system flush and a new thermostat didn't help. I have the factory manual, but at some point between when the manual was printed and the car was built, the wiring was changed, so the wiring diagrams were somewhat useless. My regular mechanic gave it a shot, but didn't come up with a fix The dealer solved the problem. It was an actuator that went bad. If you can figure out which one, you can save yourself some. Below is what I ended up paying. Labor 175.50 Parts 169.50 I'm not saying that it what is wrong with your car, or that you will have to pay that much. Just letting you know how it turned out for me. I hate problems like this because sometimes the mechanic is genuinely stumped, and as they try different things their "experimenting" is at your expense. When I called the dealer, I asked the mechanic if he 1. had experience with the automatic climate control system on this make and model, and 2. if he had run across this probem and solved it before. He described the system pretty throroughly back to me (I was somewhat familiar with it after reading the manual and screwing around with the car on and off for a couple of weeks.) He also said he had seen that problem before, and was pretty sure what was wrong just from hearing my description of the problem. Oh, and I tried a different automatic temperature control head unit from the junkyard thinking that might solve the problem. It didn't. Hope this is of some help Quote Link to comment Share on other sites More sharing options...
WhiteOut Posted October 13, 2004 Author Report Share Posted October 13, 2004 Very helpful thanks for the posts. The rad hoses are all hot after driving, and the car runs on the warm side so I think I can eliminate a therostat problem. Just the same I'm going to do a system flush and install a new thermostat today since it needs to be done anyways. If that doesn't take care of the problem my next bet as mentioned is going to be to tear apart the dash and go after the servos operating the ducts that control air flow from the heater core. Woohoo!!! I somehow doubt that this is a ACC module issue, but rather a simple mechanical failure somewhere in the system. Quote Link to comment Share on other sites More sharing options...
DOHCRagtopguy Posted October 13, 2004 Report Share Posted October 13, 2004 The rad hoses are all hot after driving, and the car runs on the warm side so I think I can eliminate a therostat problem. I'll agree with that too. I wasn't aware of that data. I believe there's some kind of sensor that allows the outside air to mix with the heat from the core on the auto climate system. So perhaps that is the part the other post is referring to. Stands to reason that if that sensor is bad, it won't allow the door to open. Good luck! Quote Link to comment Share on other sites More sharing options...
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