A/C (HVAC) Problems

[Reklaw]

So, 2004 Explorer XLS v6 with manual temperature controls.

Now that it's getting warm in southern Pennsylvania I'm wanting to run my air conditioning and it's not really getting cold. It will blow what feels like very cold air and then I close all the windows and the next thing I know it's warm again. Also today I'm driving up the highway with the windows down and the air turned on max and I get off at an exit to run into a store and the air starts to feel really cold, then as soon as I get back on the highway again it gets warmer. Then when I finally get home this afternoon and shut the car off I hear what is like a hissing sound and I wonder if I have a hole in a "Freon" line.

Now for some background. I got the Ex back in September with 92k on it and I quickly realized I had to replace the blend door motor. Then I realized that the vacuum actuator on the passenger side was not attached to the mode door so I fixed that. Then I didn't have very good airflow and realized that the fresh air door was off and blocking the blower so I just pulled it out as we were quickly heading for colder weather and I didn't have time to fix it. I also have a vacuum actuator on the drivers side that is attached to some other type of mode door I think and the mode door is actually broken inside the air box but I didn't have any issues all winter.

I think the first thing I'm going to do tomorrow morning is to try and block the fresh air intake so that the system is constantly recycling the air. Beyond that is where I need the communities help. I read another forum on here about A/C problems and someone was suggesting to feel the lines in the engine compartment to see if they were properly hot and cold and I did that they other day and it seems as though the line running into the exchanger is cold like it's supposed to be and the line coming out is hot. I also don't believe I'm low on coolant because like I said it does seem to blow rather cold air at times. Also when I'm looking at the diagrams on fordparts half of the diagrams look like what I actually have in the Ex should match with the automatic temperature controls and I have manual controls. Also, as this is the XLS I don't believe they were supposed to have the message center but I did look today and I do have the ambient air temperature sensor in front of the radiator. Would a bad ambient air temperature sensor be causing my problems?

Any help from the community would be greatly appreciated. Now to resist the urge to tear the entire dash apart.

 

[Joe in NY]

What is happening is that your system is low on gas (because of a leak) and it pulls down the suction pressure and gets really cold, but it goes below the 20 psi cut out and because you are low on gas, it takes a very long time for it to activate the compressor (around 45 psi or so on suction side). So if you gas it back up you will be good to go. But you do have a leak...

 

[Reklaw]

What is happening is that your system is low on gas (because of a leak) and it pulls down the suction pressure and gets really cold, but it goes below the 20 psi cut out and because you are low on gas, it takes a very long time for it to activate the compressor (around 45 psi or so on suction side). So if you gas it back up you will be good to go. But you do have a leak...

Joe,
Thanks for the response. I saw you posted basically the same response to someone over in the modified section. So is there a fairly easy way to detect these leaks and to patch them?

 

[Number4]

Need to check for a leak and fix before putting any more refridgerant in it. Otherwise your just wasting money. Shops usually charge $39 or less to check the system.

 

[Joe in NY]

You can do a visual check easy. Look at ALL A/C connections and look for any oil and debree stuck in the oil on the A/C if any present. This will helps give you an idea of where the leak is. I had replace my A/C manifold assembly ($90) and bought 6 cans of DuPont (maker of all r134a) 12oz r134a cans ($30). I swapped out the assemblies, pulled a vacuum using a rotary compressor from an old dehumidifier. I ran it for any hour to be sure and it pulled my friends gauge set right down. Then followed the procedure for recharging. My explorer sucked 3 cans flat. Supposed to be 32 oz. But oh well. My A/C is now ice cold. Lowest fan and 60* temp setting, with head and feet, recycle air on - (this is for max a/c) My car stays plenty cold.

 

[Reklaw]

You can do a visual check easy. Look at ALL A/C connections and look for any oil and debree stuck in the oil on the A/C if any present. This will helps give you an idea of where the leak is. I had replace my A/C manifold assembly ($90) and bought 6 cans of DuPont (maker of all r134a) 12oz r134a cans ($30). I swapped out the assemblies, pulled a vacuum using a rotary compressor from an old dehumidifier. I ran it for any hour to be sure and it pulled my friends gauge set right down. Then followed the procedure for recharging. My explorer sucked 3 cans flat. Supposed to be 32 oz. But oh well. My A/C is now ice cold. Lowest fan and 60* temp setting, with head and feet, recycle air on - (this is for max a/c) My car stays plenty cold.

So I bought the $50 kit from Advance that has 2 canisters, and the U/V pen. I hooked up the gauge and it was reading low so I added the can that said it had the die in it and the gauge didn't move at all. Couldn't find any die anywhere in the bright daylight the other day as I didn't have the glasses to go along with the light.

Just went out in the dark with the light and found signs of leaks on the top of the compressor and the bottom of the compressor near one of the electrical connectors.

picture of top

picture of bottom

In daylight after I did start investigating the top of the compressor did look like there was condensation but now we know it is refrigerant.

So, a quick search of Advance Auto show about $185 for a new compressor.
My grandmother just had the compressor replaced in her '03 Windstar yesterday and it cost her $665 at the garage.

Besides evacuating the system and needing to recharge and detaching the serpentine belt and I guess the sensors, is it just unbolt and unhook the coolant lines? Of course I would need a gauge set and vacuum pump to take out moisture after this is done. Am I missing anything? I have never used the garage that my grandmother does and I could get another quote but I know they charged her 3.5 hours labor to do hers. Any suggestion on which route I should take? ooooohhhh, would a sealant work in this situation?

 

[Bobmbx]

DO NOT PUT ANTHING IN THE AC SYSTEM EXCEPT FREON AND THE CORRECT OIL!

Its fairly straight forward to yank the compressor, although that depends on where it is. You may have to remove other stuff to get to it or you may not.

Did you inspect the entire system for leakage after putting the dye in to make sure you don't have any other leaks?

 

[Number4]

It appears to be leaking out of the hose manifold to compressor seals and spraying all over the top of the compressor.
I would do compressor, condenser, accumulator, orifice tube and AC hoses.
Get the vacuum pump and air conditioning manifold gauges at Harbor Freight this weekend with a 20% off coupon.

 

[lincolnshibuya]

if it's the compressor that's leaking, you could just replace the compressor and the accumulator/dryer. The orifice tube is very cheap as well as the condenser you have the option to replace them too.

My compressor exploded inside so I have to replace lots of parts, I just cleaned the hoses since they are very easy to flush and not leaking.

 

[Reklaw]

DO NOT PUT ANTHING IN THE AC SYSTEM EXCEPT FREON AND THE CORRECT OIL!

Its fairly straight forward to yank the compressor, although that depends on where it is. You may have to remove other stuff to get to it or you may not.

Did you inspect the entire system for leakage after putting the dye in to make sure you don't have any other leaks?

I did check the entire system for leaks and the only place I found them was the compressor. I just found RockAuto has kits for very good prices so I may have to order one and then find out if any family members have the manifold gauges. By the way anyone that doesn't know, you may be able to get the gauges cheaper at Advance with a 30% off or more coupon online.

 

[Number4]

Make sure the gauges have a negative reading. The pump should pull like a negative 28 psi and be able to hold it. I've found a lot of the cheap auto part stores gauges don't go below zero.

 

[Reklaw]

It appears to be leaking out of the hose manifold to compressor seals and spraying all over the top of the compressor.
I would do compressor, condenser, accumulator, orifice tube and AC hoses.
Get the vacuum pump and air conditioning manifold gauges at Harbor Freight this weekend with a 20% off coupon.

So I picked up the manifold gauges and the vacuum pump and bought the ToughOne A/C Compressor from Advance and I get it home and look at it and the are on the side and not the top. The number on the compressor is the correct number and I check the website and the picture matches what I got. So it looks like if I don't order one from Rock Auto I'm gonna be spending a few more bucks than I thought.

 

[Onuma]

I'm gonna be spending a few more bucks than I thought

Seems to be the case with 10+ year old vehicles, doesn't it?

 

[Reklaw]

Anyone have an opinion on the best brand refrigerant. I have heard that the arctic freeze is the best but I didn't know if was safe having the extras in it like sealer and stuff to get rid of the moisture.

 

[Number4]

Just get regular R134a, any others, your not gonna have the full refridgerant amount.

 

[Reklaw]

Just get regular R134a, any others, your not gonna have the full refridgerant amount.

So when searching everything says 134a and says that includes a sealer. Also, the system is empty and I plan on pulling a vacuum to make sure all the water is out. I looked it up this morning and I should need 32 ounces to refill it as I don't have the dual zone.

So we're you saying I won't need the whole 32 ounces?

 

[Number4]

If you go to a local parts store, they should have regular R134a in the back. Most of the stuff out front and online is the 'gimmick' stuff with sealers etc.

Pull your vacuum for an hour to two. Longer the better as it boils off moisture.
Then let the gauge set for 15 mins or so to verify the needle doesn't move. If it does, you have a leak.
When you tap the refridgerant can, with the gauges still closed, crack the can hose to gauge line connection at the manifold just enough for the R134a to push out the air. You'll know when the R134a starts to come out, at which point, tighten the connection. This will keep you from putting air (moisture) back in the system.

Also, drain and measure the amount of oil that comes out of the old compressor. You'll want to put that much back in. After doing so, spin the compressor and clutch to push the oil into the lines.

 

[dieselscout80]

Also, drain and measure the amount of oil that comes out of the old compressor. You'll want to put that much back in. After doing so, spin the compressor and clutch to push the oil into the lines.

I did not think these newer rotary compressors had oil to drain. I thought the oil was mixed with the refridgerant is that not the case?

 

[Number4]

I did not think these newer rotary compressors had oil to drain I thought the oil was mixed with the refridgerant is that not the case?

System requires a certain amount of PAG oil. The new compressor may come pre loaded with a note not to drain. In that case, you may choose not to put any more in. But if you replaced other components, then you'll want to measure how much oil you drain out.

Not enough oil and the compressor will fail. Too much oil and the system won't cool.

 

[joecrna]

Never use anything with sealer. Always replace accumulator/dryer if system is opened. Look at under hood tag for correct amount of refrigerant and oil (by weight) for a complete system charge. Replace O rings at all contections that are opened with the proper type of O ring. The previous advice all seems good.

Some auto parts store refrigerant does come with oil added. Obviously this is just an average ratio of oil to refrigerant and not the best solution. Especially if you are taking the time to do the rest (pull vaccuum etc.). Oil will be in the compressor, accumulater/dryer, and some even in the lines and other components. If you flush or replace a component, that oil will be removed. All of this needs to be accounted for to gaurentee a proper recharge.

The compressor you use to pull a vaccuum will need to be of fairly high quality. Pulling this big of a vaccuum and holding it is not easy but it is very important. Unless you have or can borrow most of the equipement, the first time you do this (if you do it right) it will pretty much be a break even with what you would pay a shop. Each time after this you will of coarse save significantly.