[2fast4]

My 335i AC has been acting weird lately and here in Az it's getting hot.
During day time, if ambient temp is, say, 88 F degrees, it's nicely cold.
As amb temp climbs to 94 F degrees, it gets less cool.
And when it goes to 95+ F degrees, it no longer blow cool and now blows hot air...I can tell when it blows "stinky" smelly air as it blow water condensation.
This is about the time when AC compressor makes, best I can describe as like low "chewbacca" noise coming on and off 5 seconds apart.

The cutoff point seems to be 95 F degrees when it stops working with the smell and compressor noise.

If it's 88 F degrees for example, it's ice cold. Or at night time and works normal. I checked freon level and it's on normal level.
I'm thinking sensor problem. Anyone?

[gbalthrop]

Originally Posted by 2fast4

... As amb temp climbs to 94 F degrees, it gets less cool.
And when it goes to 95+ F degrees, it no longer blow cool and now blows hot air...I can tell when it blows "stinky" smelly air as it blow water condensation. [THAT is probably the first clue to the issue -- please tell us the operating conditions, particularly vehicle motion, causing "blowing water condensation" and WHAT vents any water comes from: footwell, facia, passenger side, driver side, etc.]
This is about the time when AC compressor makes, best I can describe as like low "chewbacca" noise coming on and off 5 seconds apart. The cutoff point seems to be 95 F degrees when it stops working with the smell and compressor noise.

My A/C has NEVER made a "Chewie" noise, but on OTHER vehicles than my 328xi, I HAVE had condensate drains plug up, causing water NOT to drain from the Evaporator coil. IF those drains are plugged, you can either get vapor blown out the facia vents, or water into the blower "squirrel cage" or both.

If you get a "tinny ringing" noise when you corner, that is likely water from the evaporator going into the blower (NOT good for blower). Also, if condensate does NOT drain, the Evaporator coil can become a "block of ice" with greatly-reduced air delivery from the vents.

I would suggest getting a helper to determine WHERE "Chewie" is hiding, EITHER under the hood (compressor) or foward and to left of Glovebox (blower motor over passenger footwell). The Actual Source of the noise, and lateral G-force when it occurs would be helpful in identifying.

If there is something going on with the Compressor NOT pumping R-134a as it should, Manifold gauges attached should offer some clues. The simplest/ Quickest way I know to diagnose the ENTIRE IHKA system is INPA. It can show you everything from Refrigerant Pressure, Compressor Valve Operation, Evaporator Temp, Various Vent Temps, Flap Positions (Mixed Air Flaps that direct air through Heater Core to moderate/ control temp), Radiator Fan Speed, Ambient air Temp, ALL without opening hood or disconnecting ANYTHING. Just Attach K+DCAN Cable to OBD II Socket and View/Save the screens.

If you have a Windows Laptop and Download/Install BMW Standard Tools (Free Download from MEGA per BimmerGeeks site link), I can attach some sample screens and instructions of how to connect to IHKA Module, or JBBF Module to read the Data.

George

[2fast4]

Thanks George. I've checked the pressure at daytime and night time.
It's the daytime that's the problem. The pressure was too high at daytime(yellow to red zone up/down with "chewie") but around 40psi at night(works normal at night).

So I let some gas out and it's normal daytime. I don't understand why it does this different behavior. It takes a while to get to max cooling effect.
Maybe I need to take it to steam car wash and blast the condenser.
I'm good for now.

[2fast4]

I have INPA laptop and will check it out later.

[Volasko]

Originally Posted by 2fast4

My 335i AC has been acting weird lately and here in Az it's getting hot.
During day time, if ambient temp is, say, 88 F degrees, it's nicely cold.
As amb temp climbs to 94 F degrees, it gets less cool.
And when it goes to 95+ F degrees, it no longer blow cool and now blows hot air...I can tell when it blows "stinky" smelly air as it blow water condensation.
This is about the time when AC compressor makes, best I can describe as like low "chewbacca" noise coming on and off 5 seconds apart.

The cutoff point seems to be 95 F degrees when it stops working with the smell and compressor noise.

If it's 88 F degrees for example, it's ice cold. Or at night time and works normal. I checked freon level and it's on normal level.
I'm thinking sensor problem. Anyone?

Do you have the fresh air dial turned to heat (ie red). Its that little dial located under the stability control and door locks button in the center trim piece. If so it is sending unconditioned hot outside air direct to the inside which KILLS ac capacity. I experienced the same thing when I got my car back after collision repair and though my shop charged my AC system wrong. Turned out it was still from my winter settings. Once I flipped that to cold it was cold as ice. I suspect you have the same thing going on since you you know the AC works when its cooler out.

[2fast4]

Originally Posted by gbalthrop

My A/C has NEVER made a "Chewie" noise, but on OTHER vehicles than my 328xi, I HAVE had condensate drains plug up, causing water NOT to drain from the Evaporator coil. IF those drains are plugged, you can either get vapor blown out the facia vents, or water into the blower "squirrel cage" or both.

If you get a "tinny ringing" noise when you corner, that is likely water from the evaporator going into the blower (NOT good for blower). Also, if condensate does NOT drain, the Evaporator coil can become a "block of ice" with greatly-reduced air delivery from the vents.

I would suggest getting a helper to determine WHERE "Chewie" is hiding, EITHER under the hood (compressor) or foward and to left of Glovebox (blower motor over passenger footwell). The Actual Source of the noise, and lateral G-force when it occurs would be helpful in identifying.

If there is something going on with the Compressor NOT pumping R-134a as it should, Manifold gauges attached should offer some clues. The simplest/ Quickest way I know to diagnose the ENTIRE IHKA system is INPA. It can show you everything from Refrigerant Pressure, Compressor Valve Operation, Evaporator Temp, Various Vent Temps, Flap Positions (Mixed Air Flaps that direct air through Heater Core to moderate/ control temp), Radiator Fan Speed, Ambient air Temp, ALL without opening hood or disconnecting ANYTHING. Just Attach K+DCAN Cable to OBD II Socket and View/Save the screens.

If you have a Windows Laptop and Download/Install BMW Standard Tools (Free Download from MEGA per BimmerGeeks site link), I can attach some sample screens and instructions of how to connect to IHKA Module, or JBBF Module to read the Data.

George

Hey George, I got into my car when it's hot weather(119 F outside sitting in driveway), ran INPA & got some screen shots(cussing like a WWI trench soldier getting burned touching things!).

I can see some of the functions BUT I don't know where to find Refrigerant pressure, compressor valve operation, evaporator temp, various vent temps which are the critical info.

It's blow hot air again today(very very hot amb 111 F), I hooked up my gas pressure gauge and it it's cycling within the Red zone again, and "chewie" sound(like bit of grinding).
As I've said that when it's mid 90s, it works well. But at this 111 F, pressure gauge went up so high that compressor is compressing but valve is closed or something.
I can see engine RPM from 640 to 900 cycling up/down.

I had to catch this problem when it's really hot to catch it not working. Later when weather cools down to 90's it works normal again.

My only other option might be to let out more gas. Also the gas pressure reading is dependent of ambient temp and not static...higher when it's hot out, lower when it's cooler.

IMG]https://photos.app.goo.gl/WS9MqyrT57HYrBQ26[/IMG]IMG]https://photos.app.goo.gl/UeVs86Cz1u2Y9ZTdA[/IMG]

[2fast4]

Originally Posted by Volasko

Do you have the fresh air dial turned to heat (ie red). Its that little dial located under the stability control and door locks button in the center trim piece. If so it is sending unconditioned hot outside air direct to the inside which KILLS ac capacity. I experienced the same thing when I got my car back after collision repair and though my shop charged my AC system wrong. Turned out it was still from my winter settings. Once I flipped that to cold it was cold as ice. I suspect you have the same thing going on since you you know the AC works when its cooler out.

Thanks I've played with the dial but to no avail. Hotter to hot.
I remember 2 years ago I took a long trip thru desert.
115 f and my AC was ice cold. Froze my hands ✋
Now it's not the same.
Maybe I need to let out more gas.

[gbalthrop]

Originally Posted by 2fast4

... ran INPA & got some screen shots... I don't know where to find Refrigerant pressure, compressor valve operation, evaporator temp, various vent temps which are the critical info...

Your Flap Positions are good for Full Cooling: BOTH Right & Left Mixed Air Flaps read "0", so NO cooled air is being directed through Heater Core.

The INPA Screen you are looking for is the Status Screen IMMEDIATELY BEFORE your other attached screen "read controller value". It is "IHKA > F5 Status > F1 "Readout Analog Inputs". I attach a ScreenPrint of that INPA Screen which I have translated to English and made Notes related to fields/Inputs.

I also attach an "IHKA Module Tutorial" which shows various screens at different conditions. I'm NOT sure what "Y-value" is, but my SWAG is that it has something to do with Compressor Valve Function, and yours is completely absent. The only way I know to monitor Compressor Function is by Refrigerant Pressure Sensor pressure value, and Evaporator Temp. You CAN find Compressor Switch (Snowflake) function for activation of Compressor in the DME Module: DME > F6 Activations > Shft+F2 A/C Compressor Relay (KOREL), which is a "Digital" On/Off circle-filled/dark when on display. It does NOT show any modulation of "degree of pumping", just ON/OFF.

I'd be interested in seeing your "F5 > F1 Analog Inputs" screen when <95F and at "Hot as Phoenix Daytime". Are you sure your radiator fan is operating? Are there leaves/debris between the Radiator & Condenser, or is the Condenser covered in mud or otherwise obstructed? Have you tried spraying water on the front of the condenser to see the effect on High Side Pressure?

Please let us know what you find,
George

[gbalthrop]

Originally Posted by 2fast4

... I hooked up my gas pressure gauge and it it's cycling within the Red zone again, and "chewie" sound(like bit of grinding).
As I've said that when it's mid 90s, it works well. But at this 111 F, pressure gauge went up so high that compressor is compressing but valve is closed or something. I can see engine RPM from 640 to 900 cycling up/down...

I would like to know the actual Low Side & High Side Numbers, with ambient temp per the dash readout. If the engine RPM is cycling, that sounds like compressor is cutting in & out due to excessive pressure. Does the High Side pressure correlate with Engine RPM change?

I would want to know WHERE the "Chewie" sound is coming from. The Expansion Valve is visible when the Microfilter Housings are removed, at the firewall, just right of center, inboard of E-box, per this TIS procedure:
https://www.newtis.info/tisv2/a/en/e...ements/OfsUqvf

The ECS parts page for that part suggests replacing "every time you service the A/C System". That sounds a bit extreme as I have NEVER had to replace an Expansion Valve, but if that is where the sound is coming from, and it ONLY makes it when its NOT cooling, then you can replace it for $25 - $30, plus o-rings:
https://www.autohausaz.com/catalog/k...ansion%20valve

George

[2fast4]

Originally Posted by gbalthrop

I would like to know the actual Low Side & High Side Numbers, with ambient temp per the dash readout. If the engine RPM is cycling, that sounds like compressor is cutting in & out due to excessive pressure. Does the High Side pressure correlate with Engine RPM change?

I would want to know WHERE the "Chewie" sound is coming from. The Expansion Valve is visible when the Microfilter Housings are removed, at the firewall, just right of center, inboard of E-box, per this TIS procedure:
https://www.newtis.info/tisv2/a/en/e...ements/OfsUqvf

The ECS parts page for that part suggests replacing "every time you service the A/C System". That sounds a bit extreme as I have NEVER had to replace an Expansion Valve, but if that is where the sound is coming from, and it ONLY makes it when its NOT cooling, then you can replace it for $25 - $30, plus o-rings:
https://www.autohausaz.com/catalog/k...ansion%20valve

George

George thanks. I have let some out and it's now working normal.
The gas was somehow too much pressure...it had been working last summer fine until I start to use it for this early spring was also was OK till the real summer 115 F in Azz came on.

The growling noise, aka chewie, was the sound of engine rpm revving up/down and compressor noise. When it reaches proper pressure, the engine revs the normal rpm and doesn't fluctuate.
So this is what I've learned. Overcharged gas will cause engine to rev up/down from 640-850 rpm. And the pressure gauge will also show yellow/red zone. And poor gas mpg. Now that it's working normal, mpg improved(compressor is NOT on all the time like when it's not working right).
It could still be colder but I need to clean out the evaporator/condenser coil as I've never cleaned them.

I will get some screens shots later to capture parameters how it's working.
Thanks.