Hottest day of the year and no A/C (hot air blowing) from the 2004 LS8

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lsintoronto

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Looks like something in the A/C system decided to give up in the last couple days - wife just told me about it this morning on the hottest day of the year so far. Took it out for a drive it and it's just blowing hot air.

In looking at past threads it appears it could be the DCCV (part # YG378) or it may be a refrigerant leak somewhere. Since I'd have to take it to a shop to test the system pressure/leaks, is there a way to test the DCCV operation at home?

Are there symptoms that show up before either one that could point to the issue? It appears the loss of cabin air cooling occurred fairly rapidly as I drove the car on the weekend and the A/C appeared to be working ok (although I didn't pay attention to how cold the air was but it was cooling the cabin).

Called my local Ford dealer to check DCCV pricing and it was $270 (Canadian) versus $106 (US) at Tasca! WTF???

Thanks!
 
lsintoronto said:
... is there a way to test the DCCV operation at home?...
Click to expand...
...
joegr said:
...Do you get ice cold air the first minute or two after first starting the car after the engine has cooled over night?
If yes, then it could be the DCCV. If no, then it's the refrigerant system.

At a stop, does it really feel like it is heated instead of just not-cooled? With the engine at temperature, come to a stop and feel the hot air (blower on manual maximum). Now set the climate control on 95 (blower on manual maximum). Does the air coming out get a lot hotter? If yes, then it's probably not the DCCV...
Click to expand...
 
A quick check for the A/C; turn engine set temperature to 16 turn steering wheel to left.
Get out of car, look behind the rubber cover behind the tire.
Is the compressor turning? Not just the pulley but the clutch too; if anything is not moving on that pulley most likely low charge.
In Canada you can get the red-teck stuff from crappy tire, it is propane/butane not 134a but works just as well.
 
joegr said:
...Do you get ice cold air the first minute or two after first starting the car after the engine has cooled over night?
If yes, then it could be the DCCV. If no, then it's the refrigerant system.

At a stop, does it really feel like it is heated instead of just not-cooled? With the engine at temperature, come to a stop and feel the hot air (blower on manual maximum). Now set the climate control on 95 (blower on manual maximum). Does the air coming out get a lot hotter? If yes, then it's probably not the DCCV...
Click to expand...

Just found out today so will try in the morning but I let it cool for several hours then went back out and tried and it was hot as soon as the car was started. Same temps on both sides.

With the second test, the temps didn't appear to get significantly hotter (but was hot to begin with). Feels like the air is heated like a blow dryer.
 
02_LS said:
A quick check for the A/C; turn engine set temperature to 16 turn steering wheel to left.
Get out of car, look behind the rubber cover behind the tire.
Is the compressor turning? Not just the pulley but the clutch too; if anything is not moving on that pulley most likely low charge.
In Canada you can get the red-teck stuff from crappy tire, it is propane/butane not 134a but works just as well.
Click to expand...

It was hard to tell but it appeared that the clutch was turning as well. I think that red-teck stuff is bad for the system over time versus trying to fix it properly. Will have to see what the issue is and cost to repair.

Thanks guys!
 
While you wait for proper resolution, you may find relief by picking up a hose pinch tool and installing it on the larger host to the heater core, wherever you can get access with enough room so as to not interfere with the objects in the immediate vicinity, and clamp that hose down to prevent water flow. That will keep water from being able to circulate through the heater core.

One strange thing to note. While bringing my car back from the dead, I could not get water to flow through my heater core, when attempting to bleed air from a cooling system fill. (it ended up that I had a broken water pump, plastic internal impeller broke off the shaft) I wasn't sure what the deal was with the problem at that point, so I pulled off the 5 month old DCCV and tested it. It fails open, and using DC power, it gets closed when you ask for no heat. Well, I could not get that valve to do anything in terms of closing on command to lowest temperature in the climate control system. Chasing cables, you name it, everything looked fine. On a whim, I pulled the battery cable for 5-10 minutes, because that thing was working right when I pulled the engine a couple weeks earlier. I wasn't buying the factory service procedure that said I needed a new DTAC module (that control panel for your climate control in the cabin). Sure enough, as soon as I restored power and turned on the system, the valve was now clicking positively before my eyes when it should have.

You may want to just break open the power connection to the battery and retry while you are waiting for the repair. I have no idea how pulling the battery cured my valve actuation problem, but it did. Later that night, after reinstalling the (generation 1) valve, I was able to find the water pump innards detached, which was why I was rapidly overheating after changing the engine. The fault was mine on this, the water pump failed on my old engine and took out a head gasket or otherwise opened the cooling system to combustion gases, but since it was a lifetime warranty replacement that had been on the engine for 5 years, I moved it to the new (110K miles) engine. Since it is a closed unit, nothing was seen or heard that indicated it was bad. I should have shaken that biotch while in transit from engine a to engine b.

Good luck.
 
Morning air temp test failed with warm air (well slightly cool) matching the ambient temp inside and outside the car this morning but definitely not "cooled".

Also forgot to mention that there is a hissing noise associated with the A/C system being turned ON. When the A/C is on the hissing is constant from the vents/dash and goes away with the A/C is turned off. It's fairly loud and competes with the vent airflow sound.
 
lsintoronto said:
...Also forgot to mention that there is a hissing noise associated with the A/C system being turned ON. When the A/C is on the hissing is constant from the vents/dash and goes away with the A/C is turned off. It's fairly loud and competes with the vent airflow sound.
Click to expand...

Usually, this is an indication that your refrigerant level is too low. However, it could be that your expansion valve has failed. Readings of both the low side and the high side pressures are required to be able to determine which it is. If you try to charge based on the low side only and the expansion valve is bad, you will over pressurize and do damage to the rest of the system.
If it does turn out that it is low, you should find the leak and repair before adding any refrigerant. A common leak on the LS is at the compressor. If it is leaking there, you will have already lost most of the compressor oil. That will have to be corrected before the compressor self destructs. (If that happens, you may have to replace the whole system due to contamination.)
 
joegr said:
Usually, this is an indication that your refrigerant level is too low. However, it could be that your expansion valve has failed. Readings of both the low side and the high side pressures are required to be able to determine which it is. If you try to charge based on the low side only and the expansion valve is bad, you will over pressurize and do damage to the rest of the system.
If it does turn out that it is low, you should find the leak and repair before adding any refrigerant. A common leak on the LS is at the compressor. If it is leaking there, you will have already lost most of the compressor oil. That will have to be corrected before the compressor self destructs. (If that happens, you may have to replace the whole system due to contamination.)
Click to expand...

Thanks joegr - so don't turn on the A/C to avoid any damage to the compressor until it's properly diagnosed. I do plan to have the system tested and checked for leaks before adding any refrigerant because if it's low there likely is a leak somewhere - I had the car at a shop on Wednesday because I needed help getting the driver wheel hub out but they couldn't test it that day so that's next on my list.
 
my 2006 Zephyr began to blow warm on passenger side,took it in was low on Freon . Waiting to find leaks now if any , hopefully a faulty Schrader valve .
 
I am having a similar problem but on dual auto the drivers side is heated air and the passenger is trying to cool. I think my problem is the DCCV. The cold start in the morning sounds like a good test, I think I'll try that in the morning.
 
BabyBoomer said:
it's cold now , for a week now . In Louisiana(yesterday the heat index was 113). So I will keep an eye on it .
Click to expand...

keep an eye on it all you want, but the car never had any Freon to begin with, and therefore can not be low on Freon...
 
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