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My car currently will not put out any hot air - even if left to idle for 20 minutes. The engine will warm to normal operating temp, I will leave the heat on (either defroster or legs/defrost with A/C off) and nothing but outside temp air. The real mystery is that when I drive the car around, it will start to put out heat when the throttle is active (above 1.2k RPM or so). What seems to be the issue?
I was recently told by a shop that I needed a new compressor and the works, and ordered replacement parts for myself. They said I needed a new compressor because the car would not pass a "live leak test" when they were trying to add refrigerant (very tiny holes on the compressor causing a leak, and they called the compressor 'shelled' which I am unfamiliar with that term in relation to a compressor).
Could there be a sensor, thermostat, something of the sort that is either activating or not activating? I am replacing the compressor regardless because it needs it and I already purchased the parts... just want to kill two birds with one stone here and make sure everything works.
Also, I did put 1.75lbs of refrigerant in to the car after it had been evacuated by the shop. The level is still above 1.5lbs after 8 weeks, so slow leak, but that is what led me to believe the shop wasn't correct in diagnosing my full issue. I know what I did isn't really safe or good for the environment, but I am human so yeah. I don't want to take it back to the shop as I was quoted $1100 for just labor on the compressor replacement, when I could just bite the bullet and do it on a Saturday.
The first step is to check and make sure that the cooling system is not low on fluid.
If the reservoir is full then the problem is the water pumps is wearing out.
The water pump is putting out enough flow for cooling the engine but not enough pressure for the heater core.
When you are raising the RPM you are increasing the pressure in the system and the heater starts working.
I had the same condition and being cold helped me solve a water leak problem as well as changing the pump.
The first step is to check and make sure that the cooling system is not low on fluid.
If the reservoir is full then the problem is the water pumps is wearing out.
The water pump is putting out enough flow for cooling the engine but not enough pressure for the heater core.
When you are raising the RPM you are increasing the pressure in the system and the heater starts working.
I had the same condition and being cold helped me solve a water leak problem as well as changing the pump.
Great info, and I see the water pump is a fairly cheap part to get. How long did the replacement take you?
Did you drain the fluid from the system, remove the battery, remove belt, the idler pulley, then the water pump? Obviously gasket on the new pump and reverse instructions?
swetnK: Since winter is upon us, let's first focus on getting you some hot air.
+1 to Vern: confirm the coolant reservoir is full. If the reservoir is full, you're not loosing coolant, and the engine warms up properly without overheating, then your water pump and thermostat are fine.
So why are you not getting hot air from the vents? Probably because the air blend door is stuck. It's under the dash, behind the radio and directs air either thru the heater core when the cabin temperature control is set to HI, or bypasses air around the heater core when the temperature control is set to LO. It's quite possible your blend door is stuck in a position that always directs air to bypass the heater core, even when the cabin temperature control is set to HI.
Here are two threads describing the problem in more detail, and how to fix it. They also contain more links on this topic, because other folks have fixed this problem:
DW it is possible that there is a blend door problem but when you can get heat at RPM's above 1500 it is usually the pump. As he stated he has heat but not at idle.
Vern: It's possible the water pump has worn impeller blades, but imho a stuck blend door is more likely, for two reasons:
1) If a worn impeller circulates coolant poorly at ~750 RPM (idle) and adequately above 1,200 RPM, you'd expect the temperature gauge to climb at every stoplight, and drop back to normal while driving away from the light. swetnK does not describe this situation (but I'm sure he'll clarify for us when he reads this )
2) This forum has many posts about stuck blend doors, stuck thermostats, leaking coolant reservoirs, leaky water pumps, and shot fan control modules, but few, if any, about worn impellers blades, at least that I recall reading. Which doesn't mean impeller blades don't fail, but to borrow a med school expression: "when you hear hooves, think horses, not zebras".
One other possibility that is rare, but possible: Sometimes coolant gels in the heater core when you mix two common coolants: orange Dexcool and green ethylene glycol. Hopefully that's a distant zebra, not a nearby horse Can I Add the Green Coolant to the Orange Coolant?
So why does swetnK get some heat at 1,200+ RPM but not at idle / ~750 RPM? Could be the blend door is stuck in a position that allows limited air to flow thru the heater core, enough to generate some heat when coolant circulates quickly at 1,200+ RPM, but not when the coolant circulates slower at ~750 RPM. Air always flows freely thru the radiator, so the engine does not overheat at stoplights, but a blend door stuck partially closed could cause swetnK to freeze at stoplights and thaw out as he drives away.
I could be all wet. Won't be the first time, or the last! Just my 2 cents.
Let's help swetnK warm up and we'll all learn from it.
OK so I have done a little research. I don't have much time during the week to look at the car, but can look more this weekend.
So first finding is that all of the hoses rae warm from the radiator. See the picture attached.
The previous user shows a cold line, but I show all hot... so it seems the pump is working fine getting heat to the core?
And yes, I only have the no heat at idle (though when I am driving, it is very lackluster and doesn't do great below 32 Fahrenheit). This issue began when it was in the high range of 80 Fahrenheit, and not once did my engine temp go above the normal, expected position. I will also note that the coolant level is more than sufficient in the reservoir.
If the blend door is stuck in a position to bypass the heater core, wouldn't I have an issue of no heat whatsoever? And you're saying it could be stuck in a 'partial' position, where most air is just bypassing the heater core but some is obviously making it there (basically I would be getting, say, 10% of the actual heat being generated because the door isn't opening fully to the heater core?)
I wish I could look more tonight, but no garage and it being dark and freezing.,.. will have to be done tomorrow.
*MORE NOTES* Regardless of the A/C being on or off (running the defroster, ort splitting to defroster/legs) I still ahve no heat at idle. I still allow my car to warm for 5-10 minutes so when I drive, the coolant is already warm.. but driving to work at 4:30 AM when it is 10-32 degrees is getting old quickly. Thankfully no traffic/flashing lights so no stops making me lose that heat.
*ALSO* When I switch it in to HI on the A/C control unit in the dash, I feel like I hear the "knock" or "tap" of a door opening/shutting. Obviously I will be looking at it more tomorrow, but today I think I may have ruled out a blocked-up heater core, correct?
I am trying to make sense, going back and forth between the two threads you posted, and I don't quite understand my next steps exatly.
Am I now to remove the glove box, and that will reveal the steppers?
I did find this post from Doogie, and I think this is what I need to do?
eventually the "recirc" door on the HVAC system quit moving up and down, and eventually resulted in the recirc door staying closed no matter what the setting. when trying to defrost the windshield, it just fogged up.
turns out that the motors that move the doors into their various positions (Floor/Vents/Defrost/etc) have a little pin that simply fits into a D-Shaped hole in the plastic end of the flapper door. When you want "Defrost" for example, a little motor moves the "recirc" door into the open position, so that you have fresh air coming into the cabin instead of cabin air recirculating about the area (which causes moisture to build up on the windshield).
Eventually the "D-Shaped" shaft of the little motor "twists" in the plastic flapper door, and eventually just "spins" in the plastic causing no movement. In my case, it caused the "recirc" door to not move. In your case, it is causing the Vent/Floor/Defrost door to not move. (I suspect).
The fix was to set the controls to a "home" position (i.e., set the controls to "Floor", which sets the motor to the "Floor" position), then manually moves the flapper door to the "Floor" position. Then remove the motor, coat the "D-Shaft" in Gel-Type Super Glue, and then shove the D-Shaft back into the plastic flapper door. Wait for it to dry, then test.
I think "Most" of the door motors can be removed relatively easy. Do a search for "windshield moisture" on the forum search feature and you might find some info helpful.
swetnK: You're on the right track to being warm again.
You've confirmed there's no blockage in the heater core, and when the engine is hot and idling, the water pump is circulating hot coolant (oxymoron alert ) thru the heater core. How do we know? Because the return line from the heater core, the hose labeled "cold" in the picture, has hot coolant flowing thru it when the engine is hot and idling.
And you're on the right track about the temperature blend door. Just a hunch, but I bet you discover it's stuck mostly closed, causing most of the air to bypassed the heater core, even when the temperature control is set to HI.
Stepper motor #4 is the lower actuator that rotates the temperature blend door. You will probably discover that yours is not rotating the blend door properly. Sometimes the fix is as simple as a drop of crazy glue on the end of the shaft. Other times it's a stripped gear inside the actuator, which need to be replaced. You'll have to study yours to determine the exact problem and fix.
The good news: you should be able to restore heat quickly by manually rotating the blend door and leave it in the 'hot' position. But be careful not to push on the shaft while rotating it - some folks accidently pushed the shaft into the air box, and it's a pita to get them back into position.
Let us know what you find and we'll help you from there.
swetnK: You're on the right track to being warm again.
You've confirmed there's no blockage in the heater core, and when the engine is hot and idling, the water pump is circulating hot coolant (oxymoron alert ) thru the heater core. How do we know? Because the return line from the heater core, the hose labeled "cold" in the picture, has hot coolant flowing thru it when the engine is hot and idling.
And you're on the right track about the temperature blend door. Just a hunch, but I bet you discover it's stuck mostly closed, causing most of the air to bypassed the heater core, even when the temperature control is set to HI.
Stepper motor #4 is the lower actuator that rotates the temperature blend door. You will probably discover that yours is not rotating the blend door properly. Sometimes the fix is as simple as a drop of crazy glue on the end of the shaft. Other times it's a stripped gear inside the actuator, which need to be replaced. You'll have to study yours to determine the exact problem and fix.
The good news: you should be able to restore heat quickly by manually rotating the blend door and leave it in the 'hot' position. But be careful not to push on the shaft while rotating it - some folks accidently pushed the shaft into the air box, and it's a pita to get them back into position.
Let us know what you find and we'll help you from there.
I had a stuck blend door, my symptom was fogging windows.
The jag procedure for fixing the door looked complicated and had me worried.
When i finally went ahead with the task, i found it to be quite simple. The online procedure only needs to be used as a guide as the pics are pretty lousy. Once you get in there, with the help of the pics, it all becomes quite obvious.
Just remember to do the "reset procedure" using the heat controls once completed.
More personal notes...:
"
eventually the "recirc" door on the HVAC system quit moving up and down, and eventually resulted in the recirc door staying closed no matter what the setting. when trying to defrost the windshield, it just fogged up.
turns out that the motors that move the doors into their various positions (Floor/Vents/Defrost/etc) have a little pin that simply fits into a D-Shaped hole in the plastic end of the flapper door. When you want "Defrost" for example, a little motor moves the "recirc" door into the open position, so that you have fresh air coming into the cabin instead of cabin air recirculating about the area (which causes moisture to build up on the windshield).
Eventually the "D-Shaped" shaft of the little motor "twists" in the plastic flapper door, and eventually just "spins" in the plastic causing no movement. In my case, it caused the "recirc" door to not move. In your case, it is causing the Vent/Floor/Defrost door to not move. (I suspect).
The fix was to set the controls to a "home" position (i.e., set the controls to "Floor", which sets the motor to the "Floor" position), then manually moves the flapper door to the "Floor" position. Then remove the motor, coat the "D-Shaft" in Gel-Type Super Glue, and then shove the D-Shaft back into the plastic flapper door. Wait for it to dry, then test.
I think "Most" of the door motors can be removed relatively easy. Do a search for "windshield moisture" on the forum search feature and you might find some info helpful.
"
So I have the glove box off right now. I removed the (3) hex screws from the actuator and removed it. I see the shaft that the motor 'plugs' in to as well. When I switch between HI and LO on the system, the actuator turns the pin. I am assuming this now means that the actuator itself is fine, but the shaft is slipping and not catching.
So I turned the shaft all the way to the left, A/C off, set to FLOOR. I had air that was actually turning warm, though not hot (the engine is at full operating temp, as I ran the car before working on it. I also had the motor running while testing all of this). When the shaft is set all the way to the right, it is outside temperature air (cold!).
Then I turned the shaft all the way to the left again, A/C on, set to DEFROST. Now this time, I did not get warm air... though it is possible the shaft slid from the warm, LEFT setting to the cold, RIGHT setting because I was trying to stick my other hand up to the windshield and feel the air to determine the temperature.
The oddity I came across was that after I turned the shaft to the left and held it there, I got warm air. When I stopped holding the shaft to the left, it actually spun back to the right on its' own and made a 'thud' noise. I can repeat the process and it happens 80% of the time like that. So it's like the actuator pin isn't catching on the shaft, so it's staying at the right, COLD position and never moving from it. But is it normal for it to swing back on its' own like that?
Any help is appreciated, as I wouldn't mind having my glove box in the car before I go out tonight!
So I went ahead and super glued the actuator shaft to the pin. I had the shaft turned all the way to the right (earlier it was cold to the right, warm to the left). I let it set for about an hour, then drove the car for 20 minutes for a test drive.
Now I have a different issue... when DEFROST or FLOOR are selected, the fan does still blow to those locations. But now when I turn on DEFROST, I get tons of heat but only while driving. When I parked my car it quickly lost all heat and equilized with the outside temperature. Even weirder.. now I have no heat to the FLOOR setting, even while driving. I know I glued the correct actuator to the correct spot, as I was able to test the actuator before gluing it.
So I drive the car to a work dinner and I'm getting full heat through any vent I hoose, a/c on or not. Except when I stop.
I will note that the intensity of the heat has gone back to normal (from barely any). Just gotta figure out why it's slowing down now... can we for sure rule out a water pump that is just beginning to fail?
Im still of the opinion that the wear on the water pump is the problem. When the RPM's are up the velocity of hot water is up and at idle there isn't enough hot water flowing to give heat. You now know the blend door is working and that the heater core is not blocked. The only other part of the diagram is the water pump.
Im still of the opinion that the wear on the water pump is the problem. When the RPM's are up the velocity of hot water is up and at idle there isn't enough hot water flowing to give heat. You now know the blend door is working and that the heater core is not blocked. The only other part of the diagram is the water pump.
At this point sounds like a good idea to change the water pump, cheap and easy and if your milage is high its just makes sense.
Plus if it doesn't cure it then thats another possibility ruled out
One caveat: The small bolts are only hand-tight, 7 ft-lbs for the water pump, 8 ft-lbs for the camshaft pulley.
The water pump's primary job is to circulate coolant thru the engine and radiator; its secondary job is supplying the heater core. If the impellers are so worn there's little circulation thru the heater core when the engine idles, then you'd expect the engine temperature to climb and eventually overheat at idle. But swetnK doesn't mention this problem.
Just spitballing......... Maybe swetnK has a partial blockage in the heater core. PanamaJag discovered his heater plugged with "gunk" when he flushed it with a garden hose. The "gunk" is likely gelled coolant caused by a former owner mixing green glycol antifreeze with the orange Dexcool normally in our X-Types: https://www.jaguarforums.com/forum/x...4/#post1072662
Just my 2 cents. It will be interesting to hear from swetnK what's really causing cool air at idle, and hot air while driving.
So, winter weather moved in... and since I live at an apartment, my options are limited. My neighbor owns a local shop, so today he is running a pressure test on the system and looking for leaks... it was only $39.99+tax to have them do it, whereas a full flush and coolant replacement would run $149.99 (more expensive than I remember!).
After they diagnose it, I'll be doing the repair.. so long as it isn't something out of my range. Thanks everyone for the help so far, you've saved me lots of money by helping me narrow down my problem.
One thing I will note is that I have been smelling coolant (mmm yummm syrupy) ever so lightly now and then. Nothing crazy, and so faint I thought I had just passed a car with a leak of some sort. I also noticed my coolant level went down just a little (or I just didn't look when the engine was fully warm yet, uncertain. It didn't drop much at all if it did)
12-03-2015, 03:07 PM
Engine is Warm - won't pump out heat via vents
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