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Discussion Starter · #1 ·
I have signed up here after searching a few months for an issue with the air conditioning blowing hot only. I have since bought a new car, but would like to have the 328 as a good backup.

Has anyone experienced this?
 

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I have signed up here after searching a few months for an issue with the air conditioning blowing hot only. I have since bought a new car, but would like to have the 328 as a good backup.

Has anyone experienced this?
Theres a relay that turns on the AC. It could be bad?
 

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Yeah. Before diving too deep I would verify your system is full either with an evac and recharge or atleast a pressure check with a manifold guage set.
E90s are common to have the evaporators leak
 

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Discussion Starter · #7 ·
Yeah. Before diving too deep I would verify your system is full either with an evac and recharge or atleast a pressure check with a manifold guage set.
E90s are common to have the evaporators leak
I'll pick up a recharge and see how much it uses. Does auto zone sell a gauge that can plug into the ac system?

Thanks
 

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You can buy a guage set but DO NOT put that crap they sell at autozone in your car. It’s called “A/C Pro” and it’s garbage.
Could it make it cold? Maybe. Maybe. But there’s a lot of garbage in those cans that has no business in your system.
The propellant used is mostly inert gasses and I’ve heard propane but I don’t know how true that is. The only thing that should be in your system is R134a and refrigerant oil.
I would head to a shop to get a proper evac and recharge…or atleast see if it’s low
 

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... air conditioning blowing hot only. I have since bought a new car, but would like to have the 328 as a good backup.
Do you know where the relay is?
Thoughts:
There are several hundred (or more) possible causes of "AC blowing hot". Folks on the Forum regularly try to help diagnose an issue such as yours, but "Garbage IN -- Garbage OUT" applies here. Without DETAILS (those pesky little things that make life difficult ;-) all you'll get is BS, and NO FIX.

First, there is NO relay for the A/C Compressor, OR for the A/C Control Panel or Blower. Those components are controlled by the IHKA or Climate Control Module, AND by the JBE (Junction Box Electronics) Module. Some older models, and models OTHER than the E9x as sold in US, had Compressor Clutches and relays, but US E9x does NOT, AFAIK.

I presume "AC blowing hot" means the Blower Motor operates, and the Climate Control Panel lights, and you can regulate Blower Speed with buttons on Panel, but the air delivered from the Vents is never cool, even in morning on cold engine start? If that is the case, the most likely suspect is that your R-134a refrigerant has leaked out of the system, and the compressor valve will NOT activate (there is NO "clutch" on 328i/xi in US) due to low Refrigerant Pressure. There is a Pressure Sensor which could be defective, be disconnected, etc.

If your AC worked last summer, and heat worked during winter, and blower now works, AND it doesn't cool even on Cold Engine Startup (Before Coolant warms the heater core), then there is SOME fault in the Refrigeration Circuit. Minimum requirement on your end to DIY (DIAGNOSE It Yourself) with Forum help: Can Tap with Gauge, $12 & up -- Amazon example:
Manifold Gauges that will read BOTH the High Side and Low Side (larger port where you attach "charging hose" or Can Tap) are preferable for total DIY A/C service, including charging to proper level WITHOUT expensive evacuation equipment:

Both the Can Tap with Gauge (Low side pressure reading ONLY), and the Manifold Gauge set will work on ANY vehicle with R-134a Quick-connect ports. Just make SURE whatever you get has the Quick-Connect R-134a fitting(s) included, and NOT just the smaller R-12 screw-on fitting for connection to Vehicle Port(s).

If you have a Windows Laptop and INPA (BMW Factory-Level Diagnostic Software, Free Download) BMW E9x Diagnosis is quick & easy (usually ;-). But with just the Can Tap with gauge, you can quickly tell if your system has lost charge.

SAFETY FIRST: anyone opening the refrigeration system: WEAR SAFETY GOGGLES!! Refrigerant can BLIND YOU! Any protective eyewear with side shields, such as you should wear using a chain saw is OK.

When car has sat with engine off for several hours, the refrigeration system reaches "equilibrium" where both the High Side and Low side pressures are the SAME. So the single gauge, "Low Side" Can Tap Gauge can tell you (Engine OFF) if there is enough refrigerant in the system to activate the Compressor Valve and pump the R-134a through the system (cool the Evaporator/ Cooling Coil in dash).

Just attach the "Can Tap with Gauge" (Can Tap Valve CLOSED so no refrigerant is discharged) to the LARGE "Quick-Connect" port near brake fluid reservoir on US Driver side. Pressure reading with engine OFF and not run for several hours SHOULD be in ~ 75 PSIG range. Ignore the color coded "Good/Bad" notations on the can tap gauge, as those ONLY relate to Low Side Pressure when engine is RUNNING, and compressor is pumping refrigerant. THAT is NOT what we're checking here.

Note & Record what value is read. If pressure is in 30PSIG range or below, the Refrigerant Level is SO LOW, that the Pressure Sensor signal to the JBE will NOT allow the Compressor Valve to activate. Oil is pumped along with refrigerant when compressor valve is active, and that oil is needed to prevent damage to compressor. So if pressure is too low, automatic shutoff, which is likely where you are.;)

If you want to try your hand at getting some cold air for $20 and an hour of your time, get the can tap with gauge and a can of R-134a, do that test, and let us know what you find. If you're SURE you want to DIY, get the Manifold Gauge set $30) instead of Can Tap.
George
 

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Discussion Starter · #12 ·
Would PAG oil or POE oil be the right one to purchase after buying the gauges to read the pressure?
 

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Would PAG oil or POE oil be the right one to purchase after buying the gauges to read the pressure?
Glad to see you're thinking ahead, and eager to properly fix the system. What you are asking about is sufficiently-complicated that it would NOT be helpful to the DIAGNOSIS stage we are currently in to launch into an area where many folks disagree. Loss of Refrigeration Oil may NOT have occurred in your situation.

Generally the "right one to purchase" on the facts presented so far is "NONE of the Above". :)
Usually, unless a hose or fitting ruptures and refrigerant is lost quickly, OR if a component such as the Condenser or Compressor is replaced, it is NOT necessary to add PAG oil (lubricant for compressor). If there has been a slow leak of refrigerant, that does NOT mean PAG oil has been lost.

If you see an oily patch on a hose, line, fitting or component (such as Condenser) where a LOT of dirt has accumulated on that oil, THAT is a sign of lost Refrigeration Oil, and dealing with THAT is entirely different (and takes a LOT more understanding of the system), than simply assessing current Refrigerant Charge or System Pressure at Equilibrium.

I would suggest taking it a step at a time. FIRST Step: Check Equilibrium Refrigerant Pressure and report back.:giggle:
George
 

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Discussion Starter · #15 ·
Glad to see you're thinking ahead, and eager to properly fix the system. What you are asking about is sufficiently-complicated that it would NOT be helpful to the DIAGNOSIS stage we are currently in to launch into an area where many folks disagree. Loss of Refrigeration Oil may NOT have occurred in your situation.

Generally the "right one to purchase" on the facts presented so far is "NONE of the Above". :)
Usually, unless a hose or fitting ruptures and refrigerant is lost quickly, OR if a component such as the Condenser or Compressor is replaced, it is NOT necessary to add PAG oil (lubricant for compressor). If there has been a slow leak of refrigerant, that does NOT mean PAG oil has been lost.

If you see an oily patch on a hose, line, fitting or component (such as Condenser) where a LOT of dirt has accumulated on that oil, THAT is a sign of lost Refrigeration Oil, and dealing with THAT is entirely different (and takes a LOT more understanding of the system), than simply assessing current Refrigerant Charge or System Pressure at Equilibrium.

I would suggest taking it a step at a time. FIRST Step: Check Equilibrium Refrigerant Pressure and report back.:giggle:
George

George

I have to say that I greatly appreciate your knowledge on this.

I have actively been researching this, as I have not dealt with this in the past. I was into the GM 3800 scene before getting into the 328i in 2014.

Car was the most reliable I had, only needing common oil leaks and in doing those myself, I put on a few mods. Nothing anyone would scream about.

I also understand it will be a few days of shipping on these parts, and yes I do think ahead.

Once the air conditioning system is understood, it may be something to pursue more in depth.

I'll get the tools in and send some pitches pictures too.

I don't know where to get out download the software, last thing I ordered for inpa was Disc and cable, it had Toyota names and in a language I can't read.

Thanks
 

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... I don't know where to get out download the software, last thing I ordered for inpa was Disc and cable, it had Toyota names and in a language I can't read.
INPA was written by German Folks, engineer-types, who spoke German and used (and understood) German "Labels" and Technical Terminology. They never produced a "Dumbed-Down" version for "Anglo-consumption" AFAIK.:giggle:

If you see a version in Japanese, Chinese, or Americanese (other than the Menus & an occasional "Label"), you need to download the FREE INPA & E89 Datens (Data files) Folders linked on the BimmerGeeks "Downloads" Web page. Those are links to Folders found on the MEGA Web Server. I, and many others have used those without significant issue. They have a K+DCAN Cable to connect the USB Port of your Laptop to the OBD II Socket of your 328i/xi, but if you have already ordered something else, if it works out of the box, it's probably OK for the foreseeable future, and a functional Cable should work with ANY INPA Software version available AFAIK. Worst case is spend $45 on GB Cable.

As I understand it, the Menu titles, and some of the Parameter "Labels" were translated by "Volunteers": a "Committee" of well-meaning, underpaid (NADA ;-); folks who did a reasonably-good job on an impossible endeavor: trying to correctly translate "context-sensitive" German technical language to English, often without understanding the DETAILS of how a particular system worked. So if you see a "Label", such as "Print Cooling Agent" (Original German actually means Refrigerant Pressure) that doesn't seem to make sense, post here for "2nd Opinion".;)

LINKS to Download sites for INPA and ISTA are found in the attached pdf: "E9x References 210523 Revision". Please let me know if you have any issues with download, install, or Cable Setup.
George
 

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I'm having a similar issue with my AC. I have the manifold set and measured both the low and high sides after the car had been sitting for 6 hours. I see around 30 PSI at both ports, so obviously some R-134a has leaked out but not all.

In searching for a refill can, there's the R-12a product that's supposed to be a replacement for R-12 and R-134a but there was also a combo R-134/dye/ lube in a can from Wurth. I'm not inclined to use either but it's difficult to find straight R-134, so what options, short of a garage visit do I have?
 

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I have just plain r134a cans in my garage. If you can't find them, use the stuff with the lube and dye. They don't add much lube nor do they add much dye.
 

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I'm having a similar issue with my AC. I have the manifold set and measured both the low and high sides after the car had been sitting for 6 hours. I see around 30 PSI at both ports, so obviously some R-134a has leaked out but not all.

In searching for a refill can, there's the R-12a product that's supposed to be a replacement for R-12 and R-134a but there was also a combo R-134/dye/ lube in a can from Wurth. I'm not inclined to use either but it's difficult to find straight R-134, so what options, short of a garage visit do I have?
Keep an eye on your evaporator as they are very common leak points on E90 vehicles. I would make sure whatever you use you put some dye in.
I have a different opinion than others but that doesn’t mean they are wrong. Just different opinion.
I would add oil BUT I would take it to a shop and get it done. It will probably be around 200$.
The reason is that they will evac it, vacuum the system for minimum 1/2 hour which will boil out the moisture and add the proper amount with the correct amount of oil and dye as necessary.
can you do it yourself? Probably but for 200$ it’s worth getting it done professionally in this instance IMHO
 

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Discussion Starter · #20 ·
Glad to see you're thinking ahead, and eager to properly fix the system. What you are asking about is sufficiently-complicated that it would NOT be helpful to the DIAGNOSIS stage we are currently in to launch into an area where many folks disagree. Loss of Refrigeration Oil may NOT have occurred in your situation.

Generally the "right one to purchase" on the facts presented so far is "NONE of the Above". :)
Usually, unless a hose or fitting ruptures and refrigerant is lost quickly, OR if a component such as the Condenser or Compressor is replaced, it is NOT necessary to add PAG oil (lubricant for compressor). If there has been a slow leak of refrigerant, that does NOT mean PAG oil has been lost.

If you see an oily patch on a hose, line, fitting or component (such as Condenser) where a LOT of dirt has accumulated on that oil, THAT is a sign of lost Refrigeration Oil, and dealing with THAT is entirely different (and takes a LOT more understanding of the system), than simply assessing current Refrigerant Charge or System Pressure at Equilibrium.

I would suggest taking it a step at a time. FIRST Step: Check Equilibrium Refrigerant Pressure and report back.:giggle:
George
 

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