AC vent temp won't go below 50 degrees

[CVWheeler]

The vent temp on my 2005 Expedition won't go below 50 degrees. Replaced the front expansion valve and dryer. Flushed the system and evacuated for 1 hour prior to refilling with new freon and 6oz of PAG 46. Still won't go below 50 degrees. The blend door seems to be operating correctly although I have not torn the dash apart to see. Any suggestions would be greatly appreciated. Forgot to mention that I replaced the fan clutch as well.
Also, does anyone know if the expansion valve is adjustable part# YG-397?

 

[buildingdoc]

do you happen to know what your pressures are? The expansion blocks are factory set, so no need to adjust the expansion valve. What did you flush the system with as well? If is was water based it is very important to get the flush out of everything. This would mean using dry nitrogen and doing all components. Also how did introduce the oil in the system... It should have been added to the suction side of the compressor and not in the evaporator. It will just sit in the evaporator and displace refrigerant (less heat transfer). But I would need high and low pressures to better help. A fan clutch replacement is always a good idea... especially in TX.

Matt

 

[CVWheeler]

Pressures

The pressures are about 45 / 230, temp was about 90. I put the oil in through the Low side. I flushed the Evaporator and Condensor with mineral spirits. The vehicle has a dual (split) system and both the front and rear vents read the same temp @ around 50 degrees. The only common components between the 2 are the Condensor, Compressor, and Rec/Dryer. There appears to be a filter on the liquid line just before the manifold. I do have a new compressor and manifold hose, I may put them on just to see if the AC improves.
Yesterday I pinched of the heater hose to see if the blend door may not be fully closed. Drove around for about 20 minutes, no change.
My wife's car is 2005 Navigator that has the identical AC system as my Expedition. I bought it used with 18K miles on it. Her AC has started to degrade as well although her vent temp is around 45 degrees, both front and rear. I'm starting to focus on that filter on the liquid line.

 

[stamp11127]

I don't know about the rest of the a/c guys on here but I don't use mineral spirits to clean a system. I use truck airline antifreeze - quick evap. and flood the systems until clean. I would expect that you still have some spirits in the system and have contaminated the 134a.
Oil - although you are at the recommended amount I use half. It is possible that if you didn't pull any oil out from the system it is now overloaded.
The pressure on my 99 at 80 degrees outside are 37/152.
Expansion valves are non adjustable. How much 134a did you add?

What happened that caused you to replace the expansion valve and drier?

 

[CVWheeler]

This Expedition has 2 AC systems, it takes 58oz of 134a and 14oz of oil. I put exactly 58oz of freon according to my digital scale and the dryer had no oil in it thus I added 6oz of oil. The levels are perfect. The AC pressures are also perfect based on Ford specifications. The freon is not contaminated, I left it on vacuum for 1 hour, no liquid would (except tar) maintain static state under 1 hour of vacuum.
The expansion valve is adjustable in fact I adjusted it to the recommended setting of 1 turn CCW. I bought this vehicle used with a known weak AC system.
The liquid line filter is still the leading suspect, I'll change out the hose and the compressor tomorrow and see what happens.

 

[Hamfisted]

I wasn't sure what my temps from the vents were so I went out and measured 'em with a Fluke IR meter and I got a range from 18-25 degrees in the recirculate mode on medium fan speed. I'm in south Florida and it's 90 degrees outside today. My AC line pressures are 35/250. Are you getting the same temps from both rear and front vents ?



-Mike




This is taken about 6" from the center vent ....

 

[CVWheeler]

Dang man, 18 degrees. All my vents have the same temp around 50 degrees. Do you have a dual system ( Front and Rear systems)?

 

[Hamfisted]

Yes, it's a '03 Expedition. I generally run it in recirculate mode. This pic was this afternoon, and in recirculate mode but with the passengerside door open and engine idling.
I'm the original owner. It's never been in the shop. 137k miles on it. Same out of the front and back. Try adding a little Freon to the system and see if it drops the temps.


-Mike

 

[CVWheeler]

I have exactly 58oz in the system, I don't want to overcharge it. It has to be the filter in the liquid line. I'll change it out tomorrow. One other question, does your 03 have expansion valves or orifice tubes?

 

[Hamfisted]

Just the expansion valve. I believe '03 and newer have only the expansion valve.


-Mike

 

[buildingdoc]

I would like to see a sub 40psi on the low side. 90 degrees cooling past a 40 degree evap should produce about 55 degree air. on recirc... a little better. Here is a link for a pressure temp chart for R134a at the end of my post. Another thing could be that the suction reed valve isn't functioning properly and the compressor is on the way out. the way to compensate is dropping the charge to get a proper low side reading. I would rule out the liquid line filter as you would have a icing up after the filter due to a restriction and a higher than normal high side reading. If you do plan on doing the compressor, I would be careful with the brand. Some aftermarket tooling is similar, but downsized 10%.

For Hamfisted... we all like your cold temps at the register... except when you ice up the evap due to frozen condensation. You will notice the air flow diminishing after a while... then no air like the fan is off. You can also short cycle the compressor due to the low pressure switch cutting in and out... then the compressor clutch will fail prematurely

Redirect Notice

 

[Hamfisted]

I would like to see a sub 40psi on the low side. 90 degrees cooling past a 40 degree evap should produce about 55 degree air. on recirc... a little better. Here is a link for a pressure temp chart for R134a at the end of my post. Another thing could be that the suction reed valve isn't functioning properly and the compressor is on the way out. the way to compensate is dropping the charge to get a proper low side reading. I would rule out the liquid line filter as you would have a icing up after the filter due to a restriction and a higher than normal high side reading. If you do plan on doing the compressor, I would be careful with the brand. Some aftermarket tooling is similar, but downsized 10%.

For Hamfisted... we all like your cold temps at the register... except when you ice up the evap due to frozen condensation. You will notice the air flow diminishing after a while... then no air like the fan is off. You can also short cycle the compressor due to the low pressure switch cutting in and out... then the compressor clutch will fail prematurely

Never a problem with this truck's A/C system. Cold as a witch's tit from day one. I can't run it on max cold without freezing my ass off, so once the interior cools down I'll bump up the temp setting to where it's comfortable. Usually around 68 or so. The only thing I don't like about the system was the lack of an air filter. I may look into a retro kit.


-Mike

 

[JUST4FUN]

Dirty condenser ? Look up "brr its cold in here" look under my name for the post , my phone won't paste the link.

 

[CVWheeler]

Replaced the compressor and liquid line, no change. What I thought was a filter on the liquid line is a accumulator. I sawed the old one open and its just an empty chamber. I'm running out of ideas, I avoid the dealership as much as possible but I may have to take it to them and see what they think.

 

[CVWheeler]

The condensor is the only thing common to both the front and rear systems that I haven't replaced yet. I did take the hose to it and the vent temp didn't change much.

 

[JUST4FUN]

Wondering if the mineral spirits settled in the evap or the condenser causing a heat transfer problem?

 

[CVWheeler]

Nope, the AC was doing this before I flushed it. Other than the evaps there are only 2 parts left, the rear TXV and the condensor. I flushed the condensor but it may have an internal obstruction that is causing a partial blockage but the high side would read abnormally high if that was the case.

 

[stamp11127]

If you have a temp gun, post the line temps into and out of the condenser and evap.

 

[CVWheeler]

After educating myself on different consensor configurations and the symptoms associated with a bad condensor for each configuration it has to be the condensor. My 2005 Expedition has a "Parallel" condensor, if some of the lines were clogged it would not efficiently dissapate heat, this would manifest itself as higher temps at the vents without a major increase in pressure. Flushing the condensor would have no effect as the flush would just 'go-around' any clogged lines. I ordered a new one. I'll update this post when I get the condensor installed.

 

[svfetter]

After educating myself on different consensor configurations and the symptoms associated with a bad condensor for each configuration it has to be the condensor. My 2005 Expedition has a "Parallel" condensor, if some of the lines were clogged it would not efficiently dissapate heat, this would manifest itself as higher temps at the vents without a major increase in pressure. Flushing the condensor would have no effect as the flush would just 'go-around' any clogged lines. I ordered a new one. I'll update this post when I get the condensor installed.

Personally, I am no A/C expert but I have owned Fords all my life and have charged or added refrigerant to several of my cars and trucks.

I believe you may be overthinking the issue. Many dealers would tell you that 50 degrees is good. Not good enough for me. I believe just adding some refrigerant will get you to where you want. Sounds like you have all the hardware issues taken care of.

I have a 2011 Expedition and it was a little weak at first. I also know that Ford tends to undercharge at the factory. Added 3oz of maxicool and that helped. On a hot day I can get 45 to 50 degrees on the driver door vent. I would like it to be a little better but that is not too bad. Good Luck