E70 sprayed out all Freon

[Serf27]

I was towing a van with my e70 35i yesterday.
Everything was fine.
Unloaded the van and was going to return the trailer when I heard a screeching sound that lasted a few seconds. When the screeching stopped, smoke blew from under the hood.

This morning the AC is hot. I now realize the smoke from the engine bay yesterday must have been the AC Freon.
Visually everything looks fine from the top. no torn ac lines.

Has anyone seen or heard of this?

[2011with140k]

Originally Posted by Serf27

I was towing a van with my e70 35i yesterday.

I'm guessing this is the part that was a bad idea.

[Sophisticated Redneck]

Originally Posted by Serf27

I was towing a van with my e70 35i yesterday.
Everything was fine.
Unloaded the van and was going to return the trailer when I heard a screeching sound that lasted a few seconds. When the screeching stopped, smoke blew from under the hood.

This morning the AC is hot. I now realize the smoke from the engine bay yesterday must have been the AC Freon.
Visually everything looks fine from the top. no torn ac lines.

Has anyone seen or heard of this?

Most likely will be a crack in one of the rubber lines that will be hard to spot. I would grab a manifold set and vacuum pump off Amazon if you don't have one already, hook up the manifold and verify pressures to see if it's on the low side or high side (most likely high and both pressures will probably be zero). If it is at zero then hook manifold to 100psi air compressor and let in through high side valve. You should be able to hear where leak is coming from.

Replace line, pull vacuum on system and refill plus add leak detection dye for future just in case.

Also recommend getting inexpensive digital scale that can measure grams for weighting freon cans, you have to be precise with how much you fill (sticker under your hood should say exact amount in grams)

[RL18]

Originally Posted by Sophisticated Redneck

Most likely will be a crack in one of the rubber lines that will be hard to spot. I would grab a manifold set and vacuum pump off Amazon if you don't have one already, hook up the manifold and verify pressures to see if it's on the low side or high side (most likely high and both pressures will probably be zero). If it is at zero then hook manifold to 100psi air compressor and let in through high side valve. You should be able to hear where leak is coming from.

Replace line, pull vacuum on system and refill plus add leak detection dye for future just in case.

Also recommend getting inexpensive digital scale that can measure grams for weighting freon cans, you have to be precise with how much you fill (sticker under your hood should say exact amount in grams)

They use rubber lines on the ac system?

Definitely should add in doing a pressure test with nitrogen for 24hrs, then pull into a vacuum atleast 3 times for 20mins or so charging with a few psi of nitrogen after each vacuum (nitrogen will help pull the moisture out). If you really want to get fancy a micron gauge should be used to make sure you're getting a vaccum under 1000microns (ideally 500microns). Definitely want to be sure the system is very clean considering it's open to the atmosphere and there's probably a ton of moisture in there now with you driving around. And when you go to weigh in your charge, purge the hose before you open the gauges and let it into the system.

[Serf27]

Thank you guys for the replies!
The leak is probably a hard to spot crack.
Pulling a vacuum or filling with air sounds like something I can do. Replacing the ripped line I can definitely do.
When it gets to weighing the Freon or filling with nitrogen/micron gauges, I am completely lost.
I drove the car 15 miles total since this happened. I’m not sure how much moisture made it in there now.
Does this gauge set with vacuum pump look like it will work?
3CFM 1/4HP Single Stage Vacuum Pump and 3-Way Manifold Gauge Set for R12, R22, R134A, R502 Refrigerants with with Brass Valve Body for HVAC A/C Refrigeration Recharging and Maintenance https://www.amazon.com/dp/B08FHPH1N8...ing=UTF8&psc=1

[Blackbeard 1706]

I can't speak for my e70, but my Ford diesel truck will routinely barf it's refrigerant charge if it's overheated. It's a pressure blow-off valve that keeps hoses from exploding if the temp/pressure gets too high, commonly from towing. I've thought of adding an auxiliary fan in front of the radiator, but being in the a/c trade, it's just as easy for me to fill it back up.

[Sophisticated Redneck]

Originally Posted by Serf27

Thank you guys for the replies!
The leak is probably a hard to spot crack.
Pulling a vacuum or filling with air sounds like something I can do. Replacing the ripped line I can definitely do.
When it gets to weighing the Freon or filling with nitrogen/micron gauges, I am completely lost.
I drove the car 15 miles total since this happened. I’m not sure how much moisture made it in there now.
Does this gauge set with vacuum pump look like it will work?
3CFM 1/4HP Single Stage Vacuum Pump and 3-Way Manifold Gauge Set for R12, R22, R134A, R502 Refrigerants with with Brass Valve Body for HVAC A/C Refrigeration Recharging and Maintenance https://www.amazon.com/dp/B08FHPH1N8...ing=UTF8&psc=1

I would recommend this kit instead: https://www.amazon.com/VIVOHOME-Mani.../dp/B07FSZNBK6 it will be easier to use for cars.

The first step will be to see if any pressure is in the system with the manifold set. If there is still pressure, then it was never a full leak and most likely a high pressure vent like blackbeard mentioned. In that case I would recommend completely evacuating the system, pulling the vacuum, then filling and driving and see if its all good. If it all leaks out again then you know its a cracked line and time to troubleshoot it as I mentioned above.

As for using the digital scale, super easy to do now that all Freon cans have self-closing valves in them. So basically you weight your new can, write down this number, then empty as much as you can into the system with the first can. Weight the can again and subtract, now you know exactly how much Freon was put in. Now do the same for the second can. Most systems take around two to 2.5 cans. My X5 calls for 1.5 pounds which is 24.64 oz or just over two 12oz cans of Freon. However you will never get 100% of the 12oz of freon out so best get 3 12oz cans. The margin of error is +- .02 pounds so this is why I recommend converting to grams.

So weight and put in the 2 cans, then on the third you will know exactly how much you need to put in (this is assuming your system also calls for 1.54 pounds.

Jump on youtube and watch a bunch of videos to learn how to properly put in Freon. Super easy to do, just have to be careful not to do newbie mistakes like accidentally leaving the high side valve open on the manifold when filling with Freon or leaving that same valve closed when pulling a vacuum. The you tube videos will go over everything.

ProTip: When pulling the vacuum, you need to let the pump run for 30+ min to boil off all the moisture, put a fan blowing on the vacuum pump, they get very hot and this will greatly extend its life.

[RL18]

Originally Posted by Serf27

Thank you guys for the replies!
The leak is probably a hard to spot crack.
Pulling a vacuum or filling with air sounds like something I can do. Replacing the ripped line I can definitely do.
When it gets to weighing the Freon or filling with nitrogen/micron gauges, I am completely lost.
I drove the car 15 miles total since this happened. I'm not sure how much moisture made it in there now.
Does this gauge set with vacuum pump look like it will work?
3CFM 1/4HP Single Stage Vacuum Pump and 3-Way Manifold Gauge Set for R12, R22, R134A, R502 Refrigerants with with Brass Valve Body for HVAC A/C Refrigeration Recharging and Maintenance https://www.amazon.com/dp/B08FHPH1N8...UTF8&psc=1

The micron gauge isn't really "needed" but you should make sure that it's pulling into vacuum, otherwise you have a leak. The nitrogen pressure test is the proper way to check for a leak because nitrogen doesn't change pressure based on temperature like "air" does. Plus nitrogen will help draw moisture out the system. Most HVAC parts suppliers will sell nitrogen tanks, then you'll need a regulator to bring the pressure down.

If you want a step by step it's basically:
-pressurize with nitrogen atleast 100psi, let it set 24hr. Make sure the pressure hasn't dropped more than I'd say 20psi.
-if it holds pressure, put on the vacuum pump for 20-30mins, at the end, close gauges and shut off vacuum pump.
-disconnect line from vacuum pump and connect to nitrogen tank, purge the line up to the gauges, and pressurize a couple psi (maybe 5psi, you don't need a lot).
-disconnect line from nitrogen tank and connect to vacuum pump. Screw on slowly because you'll have some pressure come out and you don't want to blow oil out the vacuum pump. Turn on vacuum pump, slowly open up one side of the gauges (don't open to quickly or you'll again blow oil out of the vacuum pump) once the you start pulling into vacuum on the gauges open the gauges completely.
-repeat 2 more times
-after last vacuum, again shut gauges, disconnect from vacuum pump and connect to the refrigerant cylinder (flip upside down for liquid). PURGE THE LINE up to the gauges (you don't want to get air into the system that you just cleaned so thoroughly). Do not loosen the connection fast just a little bit until you see some liquid come out then close (be careful not to let the refrigerant nip you, a few seconds of contact to skin could cost you a finger)
- open one side of the gauge usually you charge the suction line (the bigger line). Don't crank it open fast but gradually open it till you reach the desired "weight"(If you can't get the complete charge in, run the ac system and finish charging to proper weight, when the system is running you have to "meter" the refrigerant slowly at the gauges since your putting liquid into the vapor side of the system)

If this all seems like too much it would be better to have a shop do it for you. It's really important to get this right because any air or moisture in the system will cause havoc and the system won't work correctly or even worse you kill the compressor. Also be sure no one can see you doing this cause you can go to jail and get a hefty fine without a license to handle refrigerant.

Edit: I forget that you won't be able to buy a r134a cylinder like I can, so definitely follow what Sophisticated Redneck said about charging with the cans (still though purge the gauges before you open them to let freon in the system)

[Serf27]

Originally Posted by Blackbeard 1706

I can't speak for my e70, but my Ford diesel truck will routinely barf it's refrigerant charge if it's overheated. It's a pressure blow-off valve that keeps hoses from exploding if the temp/pressure gets too high, commonly from towing. I've thought of adding an auxiliary fan in front of the radiator, but being in the a/c trade, it's just as easy for me to fill it back up.

I believe this is what happened. I poked the Schrader valve on both high and low side and they were still under pressure.
The x5 had sat for about an hour after the tow. During the tow it was fine.
After it sat for an hour, I moved the boat from the backyard up to the driveway which took about half an hour with the engine on, idling or barely moving at very low RPMs. Car then sat off another 30 minutes and when I took the trailer, I saw the Freon coming out.
I don’t see a purge valve anywhere.
I studied AC systems about 9 years ago in school and never worked on them so I’ve completely forgot it all.

Originally Posted by Sophisticated Redneck

I would recommend this kit instead: https://www.amazon.com/VIVOHOME-Mani.../dp/B07FSZNBK6 it will be easier to use for cars.

The first step will be to see if any pressure is in the system with the manifold set. If there is still pressure, then it was never a full leak and most likely a high pressure vent like blackbeard mentioned. In that case I would recommend completely evacuating the system, pulling the vacuum, then filling and driving and see if its all good. If it all leaks out again then you know its a cracked line and time to troubleshoot it as I mentioned above.

As for using the digital scale, super easy to do now that all Freon cans have self-closing valves in them. So basically you weight your new can, write down this number, then empty as much as you can into the system with the first can. Weight the can again and subtract, now you know exactly how much Freon was put in. Now do the same for the second can. Most systems take around two to 2.5 cans. My X5 calls for 1.5 pounds which is 24.64 oz or just over two 12oz cans of Freon. However you will never get 100% of the 12oz of freon out so best get 3 12oz cans. The margin of error is +- .02 pounds so this is why I recommend converting to grams.

So weight and put in the 2 cans, then on the third you will know exactly how much you need to put in (this is assuming your system also calls for 1.54 pounds.

Jump on youtube and watch a bunch of videos to learn how to properly put in Freon. Super easy to do, just have to be careful not to do newbie mistakes like accidentally leaving the high side valve open on the manifold when filling with Freon or leaving that same valve closed when pulling a vacuum. The you tube videos will go over everything.

ProTip: When pulling the vacuum, you need to let the pump run for 30+ min to boil off all the moisture, put a fan blowing on the vacuum pump, they get very hot and this will greatly extend its life.

I just remembered I do have a digital scale. So weighing and adding them should be easy. Opening and closing valves is what I’ll need to watch some videos on.
Waiting for the kit to arrive now.
I hooked up one of those gauges that come with the auto parts Freon cans.
It was reading 140 psi and beyond the red “danger/full” zone.
I released some Freon and brought it down for the “full” area and it didn’t make a difference. AC is still hot.

Originally Posted by RL18

The micron gauge isn't really "needed" but you should make sure that it's pulling into vacuum, otherwise you have a leak. The nitrogen pressure test is the proper way to check for a leak because nitrogen doesn't change pressure based on temperature like "air" does. Plus nitrogen will help draw moisture out the system. Most HVAC parts suppliers will sell nitrogen tanks, then you'll need a regulator to bring the pressure down.

If you want a step by step it's basically:
-pressurize with nitrogen atleast 100psi, let it set 24hr. Make sure the pressure hasn't dropped more than I'd say 20psi.
-if it holds pressure, put on the vacuum pump for 20-30mins, at the end, close gauges and shut off vacuum pump.
-disconnect line from vacuum pump and connect to nitrogen tank, purge the line up to the gauges, and pressurize a couple psi (maybe 5psi, you don't need a lot).
-disconnect line from nitrogen tank and connect to vacuum pump. Screw on slowly because you'll have some pressure come out and you don't want to blow oil out the vacuum pump. Turn on vacuum pump, slowly open up one side of the gauges (don't open to quickly or you'll again blow oil out of the vacuum pump) once the you start pulling into vacuum on the gauges open the gauges completely.
-repeat 2 more times
-after last vacuum, again shut gauges, disconnect from vacuum pump and connect to the refrigerant cylinder (flip upside down for liquid). PURGE THE LINE up to the gauges (you don't want to get air into the system that you just cleaned so thoroughly). Do not loosen the connection fast just a little bit until you see some liquid come out then close (be careful not to let the refrigerant nip you, a few seconds of contact to skin could cost you a finger)
- open one side of the gauge usually you charge the suction line (the bigger line). Don't crank it open fast but gradually open it till you reach the desired "weight"(If you can't get the complete charge in, run the ac system and finish charging to proper weight, when the system is running you have to "meter" the refrigerant slowly at the gauges since your putting liquid into the vapor side of the system)

If this all seems like too much it would be better to have a shop do it for you. It's really important to get this right because any air or moisture in the system will cause havoc and the system won't work correctly or even worse you kill the compressor. Also be sure no one can see you doing this cause you can go to jail and get a hefty fine without a license to handle refrigerant.

Edit: I forget that you won't be able to buy a r134a cylinder like I can, so definitely follow what Sophisticated Redneck said about charging with the cans (still though purge the gauges before you open them to let freon in the system)

I have no clue where to purchase nitrogen tanks here. Maybe I can look around.
Would it be bad if I just pulled a vacuum/check for leaks and then fill with Freon?
It does seem complicated, once the gauges are here, I’m sure I’ll figure it out.

[Blackbeard 1706]

When you tried to fill it using the auto parts store refill can, was the compressor running?
Did the clutch pull in on the pump?
If not, static pressure without the pump running will read deceivingly high. You must insure the pump actually spins. It will have a low pressure switch that will keep it deactivated under a low pressure situation, but generally will energize the clutch on the pump as you start to fill.
You may need to check fuses.

Your ac system certainly does have a pressure release valve, I couldn't tell you where it's located, but I did see x5's '03-'10 carry the same part number for it.

Having residual pressure still left in the system is a reassuring sign, affirms there was no contaminants drawn into the lines. Personally, I would simply recharge it.

I've been a refrigeration tech since 1985.

(You can rent a one ton truck from Home Dept for $19.95 a day, unlimited mileage....for towing old vans)

[Serf27]

Originally Posted by Blackbeard 1706

When you tried to fill it using the auto parts store refill can, was the compressor running?
Did the clutch pull in on the pump?
If not, static pressure without the pump running will read deceivingly high. You must insure the pump actually spins. It will have a low pressure switch that will keep it deactivated under a low pressure situation, but generally will energize the clutch on the pump as you start to fill.
You may need to check fuses.

Your ac system certainly does have a pressure release valve, I couldn't tell you where it's located, but I did see x5's '03-'10 carry the same part number for it.

Having residual pressure still left in the system is a reassuring sign, affirms there was no contaminants drawn into the lines. Personally, I would simply recharge it.

I've been a refrigeration tech since 1985.

(You can rent a one ton truck from Home Dept for $19.95 a day, unlimited mileage....for towing old vans)

Thanks.

I’m not sure if the if the compressor was running.
I’ll look at it again and see if the pump is on. I was checking fuses the other day for an unrelated issue, I don’t think I messed with the AC fuse but it’s a possibility.
I did not know about the Home Depot truck rental. I’ll probably go that route next time I need to tow something.

[Serf27]

The Fuses that have the snowflake emblem, which I assume means AC are all good.
The clutch does not move on the pump when the car is running.
I poured a little bit of water on it to see if it would move (saw someone do this in another thread)
And it didn’t move.

Could it be so low that the clutch doesn’t move?
I released some yesterday because I didn’t know AC clutch off would give high readings + the Freon it lost last week on its own.

[Blackbeard 1706]

yes.
It could be too low to trigger the low pressure switch and bring on the pump, even though your "plus or minus" readings indicated red on the disposable gauge.
Static pressure is not to be confused with running pressure.
The low pressure safety switch will allow the compressor to run or not, generally as you start to fill, you will satisfy it, and the pump will bump on/off as you fill.

You will see a lot more when you have an actual set of gauges and can watch it work.

I see the X5 uses a "pressure transducer", not a switch, so I assume it's not going to be something you can physically jumper and manually bring on the pump to charge.
I haven't owned an X5 nearly as long as you have, and as always, bmw systems are a bit unique.

[RL18]

Originally Posted by Serf27

I have no clue where to purchase nitrogen tanks here. Maybe I can look around.
Would it be bad if I just pulled a vacuum/check for leaks and then fill with Freon?
It does seem complicated, once the gauges are here, I'm sure I'll figure it out.

Buy it online. A quick search gives me this:

Tank: New 20 cu ft Steel Nitrogen Cylinder with CGA580 Valve https://www.amazon.com/dp/B01E2TAN06...VE9YWV1FS71YMF

Regulator: Uniweld RHP400 Nitrogen Regulator with 0-400 PSI Delivery Pressure, CGA580 Inlet Connection and 1/4-Inch Male Flare Outlet Connection https://www.amazon.com/dp/B008HQ6GXO...HRQVXXES1HPV7A

You definitely want to use nitrogen if you do decide to evacuate. I'm in agreement with Blackbeard 1706 though. If it's still pressurized, you don't necessarily need to evacuate the system, just add freon to the system. I'm not sure what working pressures are for our ac systems are but you can look up P/T charts for r134a that will get you damn close to the correct charge on the system. You'll want to be running the system at full output while your doing it (max fan speed and lowest temp setting). If you have an electrical meter with a temp probe it would also be helpful to get a temp reading off the suction line (the big line) and coming out of your vents. I'm not exactly sure what that temp should be but maybe someone with more knowledge on our hvac system could shed some light on it. Usually, in what I do for ac work, you want your suction temp around 40f

[Thecastle]

Have you checked your A/C compressor belt? It will let off smoke as it slips and shreds. I've had to replace mine multiple times, when I was going though faulty fluid damper harmonic dampers on my 335d.

[Serf27]

The belt is fine. I replaced it 3k miles ago.
I tried to recharge the system today.
It took enough Freon to kick the compressor on but still blew hot air.
Where do I go from here?
The gauge started to read very high when it took some Freon. Eventually the can stopped releasing Freon into the system and just sort of sat there.

[RL18]

Originally Posted by Serf27

The belt is fine. I replaced it 3k miles ago.
I tried to recharge the system today.
It took enough Freon to kick the compressor on but still blew hot air.
Where do I go from here?
The gauge started to read very high when it took some Freon. Eventually the can stopped releasing Freon into the system and just sort of sat there.

You equalized, meaning the pressure in the can was at the same or lower pressure than in the system. Did you have the gauges hooked up or are you using the gauge on the can? What pressures were you reading? Blue gauge is for the vapor side (big line)
Red is for liquid side. Also what's the ambient temperature outside?

[Blackbeard 1706]

what's key here is the operating pressure, your getting closer.
Ignore the static pressure (pump not running), it's completely irrelevant.
Operating pressure should be 30-35 ish, you have to remember that pump runs off a belt, engine rpm. It could spin 1,000 rpm or 4,000 rpm depending on ac running in your driveway or freeway. The system uses a tank, or liquid line receiver to accommodate storage of excess refrigerant not used at that rpm. It's impossible for you to judge how much is sitting in that tank, which, arguably, is the nice part of starting from scratch and weighing it in by manufacturer specs, but quite a hassle, and not totally necessary due to the forgiving nature of having that tank.
You should have a spec sticker that has the oem charge listed. It's going to vary for the standard ac vs. the four zone climate control system.
The problem is the little cans, often they are 12oz cans, and you can't get all 12oz out of them. Pressure between your car and the cans will equalize and stop pulling from the can when you only have about 2/3 of the refrigerant out of the can.
you can sqeek a bit more by heating the can, lay it on the engine where the radiator fan is blowing on it.
I've always bought gas by the drum, but it wouldn't be uncommon to need three 12oz cans to effectively get 20-24oz actually into the car.

[Serf27]

I’m still using the gauge on the can.
The new gauges should be here this week.
Temperature was around 90° when I was filling it.
It’s been very hot and I’ve been avoiding using the car. It’s the biggest car we have though so I had to use it a few times and it’s almost unbearable.

I’ve used the small cans in the past, they usually always empty out. I’ve never had a can just stop filling. It is the smallest can available though and does feel like it’s full about 2/3.
Do I need a bigger can with more pressure?

[Blackbeard 1706]

It's really hard to say, I assume your getting closer, but not quite there.
If you have the four zone climate control, it may hold quite a bit, and it's hard to say how much you've added/how low it was.
Everything is guess work with the disposable "good/bad" gauge.

[Serf27]

4 zone?
It has climate controls for the rear passengers and climate control for the third row.

[Blackbeard 1706]

Yep, four independent zones was an option for that car, I've got it too (also means that you have the world's most expensive water pump).
The third row is simply a fan that steals a bit of air from the second row area, no actual cooling.
But that system takes extra 134a compared to the standard ac.
I can look under the hood of mine for specs on total charge, although relatively useless unless you intended on a recharge from scratch, even that would be really hard to be accurate without a drum and scale, and fairly unimportant anyway with the forgiving nature of having a liquid line accumulator.

Try to take line temps from the aluminum tubes near the guage ports next time you mess with it.
I think your on the right track, just not quite there.