QuestionHi once again, Bill,
Well, things didn't go exactly as planned. We do have some heat however.
They by-passed the hot water valve. It was stuck shut. They put a vacuum line on it & it sucked it open but the hose didn't get hot and there wasn't any heat. After they by-passed the water valve they loosened the return heater hose to see if there was any air in the system. Then they did all the heater hoses to check for air. There was some air. They idled the car for 15-20 minutes and shut if off and it gurgled but did not overheat. Because it gurgled they thought there was still air in the line so they loosened each heater hose again. After that they loosened the radiator cap and it hadn't overheated but antifreeze shot out of the radiator. They refilled the antifreeze in the radiator but the resevoir was 2/3 full. All this time there was warm air but never hot air even though it was set on high at 90. They idled it again & again it gurgled when shut off. They think it's an airlock that needs to work it's way out. The question I have is why they needed to by-pass the water valve, does it need a vacuum to open, if so, where would that vacuum line be other than the airconditioner? And, how can you by-pass the water valve and have it work correctly? And, it doesn't seem that just an airlock could cause the water valve to not open.
They will be running water through the hoses before and after the water valve when it gets warmer here.
I appreciate your time with this problem. It must be more frustrating for you than us. Thank you, Jackie
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Followup To
Question -
Hi Bill,
Our Cadillac is a front wheel drive. Would that make any difference?
Bill, my husband, changed the thermostat and realized the one that was in was in the opened position. (It was a fail safe thermostat) However, we believe it was installed backwards. Soooo, we have a new 195° thermostat installed correctly. We still have no heat. When it was first installed we had heat for about 15 minutes until we backed out of the driveway. Then no heat. We haven't tried to do the heater core thing yet. A friend suggested there may be an air block somewhere so he & the friend will be checking that tomorrow. If that doesn't do anything he will be doing that hose thing. Do you agree to do those things in that order?
The car has not overheated to our knowledge. Does that mean anything?
Thank you for your suggestion, Jackie
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Followup To
Question -
Hi Bill,
We're having trouble getting heat in our 1985 Cadillac Fleetwood Classic.
My husband changed the thermostat but no change. While idling when you first start it, it heats up, but as soon as you start to drive it starts blowing cool air.
We would appreciate any suggestions for correcting this problem. We live in the NE and it's 'cold'. <smile>
Thank you in advance, Jackie
Answer -
Hi Jackie, Is your classic front wheel drive or rear wheel drive? Double check the antifreeze level in the radiator once the engine has cooled off and make sure it is at the top. This acts like a thermostat that is opening too soon and maybe you got the wrong stat, should open at 195 degrees F, or it is defective and opening too soon. You may need to remove the 2 heater core hoses and run water from the garden hose through both ways as the seal tabs could be partially plugging the core internally. Make sure the hot water valve is opening completely and not restricted. One time I had found some silicone sealer restricting the flow at the valve and without removeing it it wasn't obvious. Hope that keeps the heat inside. Bill
Answer -
Hi Jackie, When then the anti freeze is put in and the engine started up sometimes it takes 15 to 20 minuits for the air to get worked out of the heater core and allow heat to come out. You may have to increase the rpm to 1500rpm for 2-3 minuits to get the air out. Make sure that the hot water valve is in the open position and feel both hoses. The valve hose should be the same temp as the upper rad hose while the other heater hose will be a little bit cooler. Because of the seal tabs that Cadillac wants put in the cooling system plugging or partially plugging the heater core happens alot. When the thermostat was installed it was put in spring end first into the engine correct? Doing the things in the order you listed makes sense. Good luck. Bill
AnswerHi Jackie, Sounds like you are on the right track. And you are right about frustrating. It seems the more you know sometimes you forget the simple things or come up against something that you have never seen before and just have to work through it. The reason for the hotwater valve is so when you want max a/c then vacuum is sent by the programmer to the valve to close it so hot coolant can't circulate through the heater core and warm up the ductwork. Normally the valve is open. The valve isn't too expensive but if you took it out you could buy a tube and put it in place of the valve. One other thing that could let air into the system is a blown head gasket. If you drain the anti-freeze down and remove the thermostat and then refill the anti-freeze until it is with-in 1/2" of the opening. Then remove the serpentine belt and run the engine for 5 minuits and watch for bubbles. If seen then take note of which side they are comming from as that is the bad gasket. When that happens sometimes I have found bolt threads that have stripped out in the block. If that happens let me know and I can further advise but wouldn't be too concerned until after the heater core has been flushed out and still poor heat. There is one other thing to try and that is to remove the glovebox and make sure the programmer arm moves all the way to hot. The arm just unsnaps and then can be moved eithor direction. Sometimes the motor gears strip out in one spot and that won't allow the door to go full hot but that won't cause bubbles in the system. Hope that helps. Bill
