Hi:

I had posted earlier seeking help and am posting on the same topic again to see if some of the experts on this community can help me find a solution. It is getting a little difficult driving the car with small kids and with no heat in the car in sub-zero temperatures!

The issue a few weeks back was that my car wouldn't heat up properly and would usually take 10-15 minutes to come to the ambient temperature (72-75 degrees). I tried going through the posts on this site and after trying out a few things, now I am getting completely cold air. (My bad, somewhere).

Here is the diagnosis done up till now:
1. Coolant topped off; not sure if it is burped properly or not
2. Door blend motor works - checked at the extremes of Lo and Hi temperatures; the lever moves from one side to the other at the temperature extremes
3. Fan works
4. The heat control valve does not seem to be moving when I changed the temperature range. I tried moving it manually and it is not stuck. Moved it back and forth a few times to make sure that it could move; cleaned with WD40 too. Tried after switching on the car, but it wouldn't move when the temperature range was changed from one extreme to the other. Perhaps this is faulty. I tried one more thing: manually shifted it to both the extremes (assuming that one would be for cold and the other for hot). Not getting hot air at any level!
5. The cable into the heat control value was hot. Also, the cable from the HCV into the car interior was hot. The one of top of it (assuming coming back from the car) was cold.
6. The car seat heating works, though seems to be taking a little more time than what it used to do earlier.

Any help / guidance in this regard would be appreciated.

Thanks.

 

I may have posted this before, there is a black box up under the steering column (above gas pedal) where the cable comes into the car that connects to the heater control valve. My cars cable somehow became disconnected, and I was experiencing no heat as well. After discovering that, and reconnecting, heat is working again. The black box has to be removed to see where the cable connects, sorry for the unexperienced terminology, but hope that it helps.

 

Well, the first thing I would do is make sure the cooling system has no air, because that's just proper maintenance.

+1 to checking the cable, but I am still troubled with how manually moving the heater control valve doesn't give you hot air.

A number of possibilities here. It could be a clogged heater core. When was the last time your coolant was flushed?

Your heater control valve could be broken as it sounds like moving it manually doesn't start the flow of the hot coolant to the heater core (if the core isn't clogged). And if the valve did seize up, this could have burnt out the motor that actuates the valve (which explains why your temp adjustments didn't cause it to move).

 

Hi:
Yes, you had posted this helpful note earlier. I had checked it out and there isn't any loose cable. Thanks.

 

Hi:
The coolant hasn't been flushed in the last few years for sure. I had filled in the coolant a few months back (simple pouring of the anti-freeze in). Not sure if that has caused an issue. Had also changed the in-cabin filter around the same time. The issue started occurring around the same time.

Even through the HCV does not seem to be moving as I change the temperature setting, the tubes going into the HCV and out from it into the car get hot! Does that provide any indication of what may be happening?

 

Did you check the thermostat?

 

Agreed with ccvno

 

Sounds like your thermostat might be slight stuck open. What makes me believe that is your engine taking longer than normal to warm up

 

If you say one line going to the heater core is hot, and the other is cold, this should be no problem to fix. You most likely have an issue with the water valve, it's cheap enough to just replace. If that does not fix it, you have a blockage somewhere in the heater core or return line. You could try removing the line and blowing it out with compress air or a hose, but this might be messy. If you can't get air or water through the line AFTER the water valve, replacing the heater core should be next on your agenda.

Just for reference, I find my car takes a LOT longer than most 'average' vehicles to heat up in <0ºF temps. 15 minutes of driving is a bare minimum before its close to comfortable in the cabin. This was my experience with my previous vehicle with a J and climate control. It just takes a while to really heat up when its that cold. To combat that, I blocked off most of the grille and use a block heater. It makes all the difference when its well below freezing. I put the block heater on a timer to turn on about 2-3 hours before I need the car in the morning, then just unplug and go on your way. The fuel savings more than compensate for the electric cost. The car starts off luke warm when its parked in the garage with a block heater. A few minutes and its up to temp. It usually heats up considerably faster if you don't use the heat until the temp gauge is at least registering something.

 

Would appreciate any pointers / links on how to check the thermostat. Thank you!

 

About the only way to check the thermostat is to remove it, and put it in a pot of water. Heat the water up on a stove with a thermometer in it and see at what temp it opens. Or if you remove it and it's already open, clearly its bad. You need to crack open the housing on the block where the upper radiator hose goes in. Coolant will go everywhere. You probably want some extra OEM coolant on hand if you do this. I'd go all out, drain the radiator and top it off with fresh coolant. You'd probably need 2 gallons for this.

It could be the issue, but I wouldn't think so. It's usually clear its stuck open if you pay attention to how it warms up, however you would probably need a OBDII scanner to read the water temp since the gauge on the dash is more of a dummy gauge and lies. You might as well just order a new one to replace it while you have it open. If you have access to an OBDII reader, you can check the coolant temp while driving. It should take something like 5 minutes in sub freezing temps before the thermostat opens. It should hit something like 176-178ºF briefly, and then drop 2-4ºF, and cycle back and forth before the block and radiator start to really warm up over the next 10 minutes or so. At some point it should be fairly stable around 178-182ºF and creep up slowly when at a light until the rad fans come on low and bring it down a few degrees.

 

well said. for 10 or 15 bucks you might as well just replace it if you're messing with it.

 

Here is an update:
All the suggestions were helpful. I just didn't think that I could take the thermostat out in this freezing temperature, so I took the car to a auto performance shop that had a good referral for honest work.

Key findings:
1. After about 15 minutes of keeping the car on and at Hi temperature setting, the temperature on the side vents was 112 deg F, and the center one was 86. The air from the central and the back (in front of the back seat) was still lower than that in the side vents. I was told that this may be how the Acura TL is designed and the flow is different.
2. Checked the climate control and the car for any error codes. No issues. No faulty codes.
3. Decided to cool the car down and check the thermostat. Spent about an hour to get the coolant temperature to about freezing in the outside cold. Thereafter, the guy took the car for a 10 minute drive, and noticed that the heat indicator was already at the half way mark. His conclusion was that we can check the thermostat, but f the issue was with that, then the temperature gauge wouldn't have gone up.

So, with all this, he mentioned that there wasn't much to check further and the car seems to b working OK. I am still not completely convinced, given that it is still taking time to even start warming up and doesn't get very hot at a high setting.

Any thoughts / suggestions?

Thanks a lot!

 

You mentioned that the blend door motor appears to be working. Have you verified that the blend door itself is moving?

Have you burped the cooling system yet?

 

@QueQue - I am having the same issue! 05 Acura TL, barely heating up... just took a 4 hour drive and I could see my breath in the car even at the end of the trip. Coolant level looks OK but I haven't touched the coolant in 6+ years. What was the final solution for your issue? Thank you

 

If the temp gauge doesn't rise to @ 1/2 way, indicating the coolant temp is low, change the thermostat.