Heating problem
 

2001 Convertible 2.7

My A/C has been having problems this summer. I would have to really rev the engine in order to get it to actually blow out cold air. It got a little bit better when I added some refrigerant, but not a whole lot. Since I don't like using air, I never took my car in to get looked at.

Now I'm having the same problem with my heat. It worked fine when the weather was a bit warmer. But now (35 degrees) I cannot get any useful heat out of the vents unless I have the RPMs above 2500. As long as I do that, it's warm enough to be uncomfortable to hold my hands over the vents. If not, then no heat.

On an unrelated matter that I am including just in case it is related; my car is having problems in the morning. It will start up fine first thing in the morning. But, if I turn the car off after driving about a mile, it does not want to start again. I have to keep the key turned for about 20 seconds in order for it to run again. The engine is turning, just not getting the spark-fuel-air combination to work. Sometimes it takes several attempts at this to get it restarted. Yesterday it happened after sitting at a red light for a couple minutes; car stalled and didn't want to start. I have not noticed this problem after driving five miles or so, and it only happens once per day (I don't have to restart it twice).

Any thoughts on any of this?

MRR

RE: Heating problem
 

Yours is an '01 convertible, right? It could be that your blend door is acting up. The blend door moves to change the proportion of cold to warm air to adjust the temperature of air being blown into the car.

There is a calibration procedure that might help. Try this, it shouldn't hurt:
[ol][*]Engine running.[*]Fan on any speedother thanoff.[*]Mode knob turned fully to the right.[*]Temperature knob turned fully to the left.[*]Push in the rear defrost button until a chime sounds.[/ol]
The heater will then go through some gyrations that take about a minute. If it discovers problems it might display error code(s) on the odometer. If it displays a zero, that's good. I have no idea where to find a decoder for codes that are displayed. Maybe somebody else on the board will know.

Unfortunately, changing the blend door actuator, according to the shop manual, involves removal of the instrument panel and heater-A/C housing - a HUGE project. Let's hope it's not that.

Another possibility is a partially plugged heater hose, but that would not explain the poor A/C performance. With the car warmed up, feel the heater hoses with your hand. If one is noticeably cooler than the other, there could be some blockage there. If it's the heater core that's plugged, then again, that's a big job requiring tearing the interior apart. If it's just a plugged hose, it's much easier.

As to the stalling, see if it's throwing any codes. That's the best place to start.

RE: Heating problem
 

Possible, but I don't think that's it. When the A/C is bad, it still blows from the A/C unit, the air is just warm and moist, like the condenser isn't working. But I'll give it a check in the morning.


Kind of foolish of me to not go check that out first. I'll do that before posting any of my problems again. ;)

RE: Heating problem
 

"When the A/C is bad, it still blows from the A/C unit, the air is just warm and moist, like the condenser isn't working."

There are three doors in the heater-A/C unit. The blend door controls the temperature by mixing warm and cool air.
The mode door determines where the air comes out: floor, dash vents or defrost, or a combination.
The recirc door determines where the air comes FROM, outside or inside.

RE: Heating problem
 

And the winner is....

Coolant was a little bit (over a gallon!) low.

That takes care of heat and stalling. A/C is still another issue. Running the above check gave me error code "AC 48". I'll try to find what the heck that means.

MRR

RE: Heating problem
 

You might have a leak in your A/C system. There are a couple of ways to find a leak. One, you can buy a leak detector with flourescent dye. It's just a can of R-134a with the dye in it. Add it like regular refrigerant. Then use a "black light" to look for traces of the dye. I borrowed one of my kids party lights for that part. In a dark garage, the dye does show up, but faintly.
The other way is an electronic leak detector. I broke down and bought one from Harbor Freight Tools. They beep annoyingly while sniffing for freon and very annoyingly when they find it.

Once you find the leak, you have to fix it, usually by replacing the part, though you could be lucky and just have a loose connection. If you can't find the leak under the hood, it could be in the evaporator core in the heater housing. That's the expensive toremove part under the dash.

My feeling on that is that for the $700 they want to fix it, I can buy a LOT of freon.(Don't tell the EPA.)

Good luck.

RE: Heating problem
 

BTW, you might want to look into the question of why the car has lost a gallon of coolant. That shouldn't happen.

RE: Heating problem
 

I did. Something is cracked, part has been ordered and will be replaced on Monday.;)