E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Thread Tools Search this Thread Rating: Thread Rating: 132 votes, 4.99 average. Display Modes
Old 05-06-2010, 12:40 AM   #1
Registered User
Join Date: Nov 2008
Location: Westchester, NY
Posts: 6,331
My Ride: 335xi Deep Sea Blue
Send a message via ICQ to delmarco Send a message via Yahoo to delmarco
Exclamation If Your AC Air Conditioning Is Blowing Warm or Hot Air Then READ THIS THREAD!

Troubleshoot and Recharge Your BMW E46 Air Conditioning AC System In 3 Minutes for less than $20

Okay. So it is officially Summer here in the North East and that means two things: It is also Summer across most of the planet (except South America , South Africa & Australia) and the forums will get inundated with tons of My AC System Is Not Working threads!

Surprisingly there have not been a solid DIY for this yet (at least a DIY that could be found with a search in a the DIY Section) hence the weekly threads about AC blowing hot air on passenger side or hot air all around.

This DIY is for those folks with cars that DO NOT have major AC issues. Last year May on the first hot day of the year I noticed my AC vents were ONLY blowing cold air on the driver's side and hot or warm air out the passenger vents.

It's 80F+ Degrees out...

And your AC is on at full blast setting but...

...no Ice Cold Air is coming thru the vents

PART ONE: 1-3 Minute Troubleshoot

The forum DIY section didn't offer much help and I didn't want to spend my entire Income Tax Return check at the dealership. Luckily for me my friend who lives down south and owns a 2004 325i told me what was up and what I need to do.

On some E46 cars apparently the system can leak a bit of charge over the winter months when the AC system is not used for long stretches of time. You usually won't notice until the first hot day of the following spring/summer season and upon turning on your AC you realized there is cold air (or only cool air) ONLY blowing out at the driver's vents and hot or warm air streaming out the passenger vents.

Your first response is to assume the entire system is broken and something big and really expensive needs to be replaced. If you are a forum member you start one of many threads concerning vents blowing hot air or AC only blowing warm-cool air from the vents.

If your car has similar symptoms, before starting a thread or taking your car to the shop you should try this very quick, easy to do and cheap DIY to see if it will fix your AC ailments.

But even before you try my DIY make sure your center vent dial is set on the blue dots for cold air. I know it seems obvious, but lots of people overlook this simple function on the E46 and other similar BMW cars since the settings are not electronically indicated on the Climate Control Read Out Display.

In fact, you can have your Climate Control set to blow cold air (or even hot air during the winter months), but the setting on this dial takes precedence and the air coming out the vents WILL ALWAYS match what the dial is set on whether it be red dots to blow hot air or blue dots to blow cool air.

Other troubleshoot areas can be the AC Belts. Make sure you have them on your car and they are not shredded or loose. Also the AC Compressor which sits under the engine block may have been susceptible to oil leakage from a bad valve cover gasket, corrosive coolant fluid leaking from a broken hose, and/or washer fluid from a broken washer fluid tank pump (all which sits directly above this expensive to replace compressor).

So check for all these things. Worse case scenario the compressor is bad and you can either pay a ludicrous amount of money ($1,500 to $2,800) to replace it or for less than that you pack your stuff up and relocate to Beaver Creek, Yukon and hang out with my friend Jeb...

PART TWO: Recharge Your BMW AC System

Once that is taken care of and your car is still not expelling ICE COLD air then go down to Auto Zone, Pep Boys, Walmart or any sizable local Gas Station or Auto Store and spend $15 to $30 on a can of R134a freon. If this is your first can you will NEED to get a kit that comes with the indicator gauge. Generally it is cheaper to buy the can that comes with a gauge attached than buying gauge and can separate. Also most likely the gauge will be reusable so next can you buy in the future you will spend less as you will only need the can alone and that costs as little as $9.00 in some places. Also if your friend or neighbor has a gauge already feel free to borrow theirs and just buy the can alone.

Here is my big blue can of 134a + (NOTE: this size lasted me two years or two recharges to my car's system)

I don't understand the difference between the technology in my fancy looking $30 can and the cheaper plain looking $10 cans without the tech jargon littered all over the can.
But I just got the can that boasted the most on the label since this was my first time recharging my AC system I wanted it to be perfect.

My can also came with a gauge that was reusable.

And a nice bright and color coded gauge and a nice clear chart perfect for the someone that never done this before. Like I said, this DIY is already in itself so easy it is hard to mess it up and with a can like this it should be a piece of cake.

Now for the Recharge DIY:
before you begin make sure your car is on, your engine is on and your Climate Control is on full blast set for the AC Cold Air Air Conditioner.

Next Go under your hood and find this small cap between the + battery terminal and Air Filter Box.

On European/Canadian/Asian models that have batteries under the hood it will be the port closest to the windshield.

There is a similar looking cap/port that sits at the front end of the bay between the washer fluid tank and head lamp housing. This is NOT the port you want so leave it alone.
And I will post a picture of it here so no one makes the mistake of touching it.

Now return to your correct port...

And begin unscrewing it. It shouldn't be too tight.

Once the cap is off you will see this. This port will give your gauge a reading of what the current pressure is in the system and will accept a charge to the system when R134a is applied.

Get your Can of R134a ready. My can had a gauge with a safety locking nozzle to prevent any mishaps during the recharge. This locking nozzle is also beneficial because you may have to shake the can whiles squeezing the trigger to apply the freon and you don't want anything to leak out during the process.

Now this is the only tricky part and here is where the gauge is super helpful. Now you do not want to overcharge the system because that would be WORSE than having a low charge. So make sure you read what your current psi is before you begin charging so you get an idea of what amount you may need to apply.

On my color coded gauge my system showed that it was filled and in the blue zone but on the lower end of the blue range. This is IMPORTANT to note because other gauges using only psi numbers may tell you that your system is full leading you to think that the problem is more deeper or elsewhere.
But make sure your system is not just filled to the lower range of full but towards the upper range before you move on.

At low blue my car was blowing cool air on the drivers vent and warm-hot air on the passenger side. At mid to upper blue my car was blowing ICE COLD air on all vents.

This lead me to believe that the AC System in our BMW cars are very sensitive to slight changes in the psi of the charge system and also our cars perhaps requires a tad more refrigerant than other cars need to produce ICE COLD air.

So once your system is fully charged and NOT OVERCHARGED you can un-hook the Can and gauge from your port, close the cap back onto the port opening and return to your cabin. If all is well with your system and there is no deeper inherent problems you will immediately feel the ICE COLD air blowing in some cases even before you get back into the car from under the hood it will be already cold in the cabin.

Sadly, our E46 BMW 3 series does not have the coveted MAX AC button on the Climate Control but once the temp is set to 59 F with the air output on high...

And the Snowflake is lit...

Then you will have MAX AC. ENJOY!

From a Professional Source:

You can if you can get your hands on the correct type of refrigerant required for your vehicle. But that is now a major problem for do-it-yourselfers because federal law prohibits the sale of R12 and R134 automotive refrigerants to "noncertified" individuals (to become certified, you must pass a written test approved by the Environmental Protection Agency (EPA) -- something which all professional A/C technicians must do before they can legally work on your vehicle). This rule has been in effect since November 1992.

The law was passed to discourage people from recharging leaky A/C systems. R12 refrigerant, which is used in all vehicles built prior to 1993, is an ozone-depleting chemical. So its sale and use is strictly regulated by the EPA. What's more, production of R12 ends December 31, 1995. After that date, the only R12 that will be available will be that which has already been stockpiled or can be recovered and recycled from existing A/C systems. As the supply dwindles, motorists will be forced to have their A/C systems converted to the new "ozone-safe" R134a refrigerant (a job which may require replacing hoses and other parts depending on the application and model year).

Until late 1994, anyone could still buy refrigerant in large bulk containers. Because of the high cost of such containers, the EPA thought few do-it-yourselfers would buy refrigerant in bulk. But even that loophole has now been plugged. So unless you're a certified professional technician, you can't buy automotive refrigerant period.

This law does not, however, make it illegal to own or use R12 refrigerant. But it does make it very difficult for the average person to obtain it.

Some companies have responded to the "refrigerant shortage" by introducing refrigerant substitutes. Unless such a product is EPA approved, however, it should not be used in your vehicle. Many of these products are flammable, which could create a potentially deadly fire hazard if your A/C system were ruptured during an accident. There is also the problem of "cross-contamination." Federal law requires professional technicians to recover and recycle the old refrigerant in your A/C system when doing A/C repairs. If there's some other kind of refrigerant in your system, it can contaminate their recovery and recycling equipment.
Recharging The A/c System

CAUTION: The high side of the A/C system is under considerable pressure. If a can of refrigerant is connected to the high side service fitting, it may explode! The system must therefore be recharged by using the low side service fitting only. If you are not sure which fittings are which, do not attempt to recharge your air conditioner yourself. Wear eye protection and avoid direct contact with the refrigerant as it can cause frostbite on bare skin.

The basic recharging procedure goes as follows:

1. Identify the low side service fitting.

2. Determine the type of refrigerant required by the system. On most 1993 and older vehicles, this would be R12. On most 1994 and newer vehicles, it would be R134a.

CAUTION: R12 and R134a refrigerants are incompatible and must not be intermixed. Use the type of refrigerant required for your A/C system only. On most 1993 and newer vehicles, there's an identification decal or sticker that tells what kind of refrigerant is required. Also, the size and design of R134a and R12 service fittings are different to avoid cross-contamination.

3. Connect a can of refrigerant to a gauge set or recharging hose and valve set. Follow the equipment supplier's directions for making the connections.

4. Open the valve momentarily on the gauge set or hose to blow all air out of the line (this is necessary to keep from introducing air and moisture into your A/C system).

5. Connect the gauge set or hose to the low side A/C service fitting on the vehicle. This is usually located near the receiver/drier or accumulator, or suction side of the compressor.

6. CAUTION: Make sure the can of refrigerant is held in the upright position so only vapor enters the line. Do not tip the can sideways or upside down as doing so will allow liquid to enter the low pressure side of the A/C system (This may cause damage to the A/C compressor). Also, never heat the can to make it empty faster as doing so may cause the can to explode.

7. Start the engine and turn the A/C system on high. The compressor should be engaged or cycling on and off (it may be necessary to jump the compressor clutch directly to the battery if the system is extremely low on refrigerant to keep it engaged). Compressor suction will pull refrigerant vapor into the system and slowly empty the can. This can take up to 10 minutes or more, so don't be anxious.

8. When the can is empty, disconnect the charging hose from the service fitting. Use care when disconnecting the "empty" can from the gauge set or charging hose as it may contain some residual refrigerant.

9. Add additional cans of refrigerant as needed until the system is properly charged.

CAUTION: The most common mistake made by do-it-yourselfers is overcharging. Too much refrigerant can reduce cooling efficiency just the same as too little refrigerant. To work properly, the A/C system needs just the right amount. Always refer to the system capacity specs in a shop manual or other source to determine how much refrigerant is required. System capacities are specified in ounces. One can of refrigerant equals about 14 oz. Usually three to four cans is enough to fully recharge a typical passenger car A/C system that was empty. If the system is low, one or two cans of refrigerant are usually all that's required.

Last edited by delmarco; 05-08-2010 at 12:29 PM.
delmarco is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 05-06-2010, 01:02 AM   #2
E46 S54B32
Registered User
Join Date: Feb 2009
Location: Miami,Fl
Posts: 1,256
My Ride: 323ci
haha radio said "chill" coincidence i guess lol..will do tommrow miami was 91 degrees today

-oem m3 front -oem m3 hood -oem m3 sideskirts-conforti intake -h&r race springs -TR Motorsport C2's -smoked corners/sidemarkers -smoked LED tails-CF CSL trunk-Black roof vinyl
E46 S54B32 is offline   Reply With Quote
Old 05-06-2010, 01:06 AM   #3
Registered User
Join Date: Jan 2008
Location: 818
Posts: 2,200
My Ride: '04 330Ci ZHP
Very nice! We def need that in Cali!

2015 BMW 335i M-sport (BSM)
2014 BMW x3 28i M-sport (BSM)
2004 330Ci ZHP SOLD and very much missed.

DIY Facelift Angel Eyes | AVIC-D3 Install | flickr
LeontiyZHP is offline   Reply With Quote
Old 05-06-2010, 01:23 AM   #4
Registered User
Join Date: Mar 2010
Location: Atlanta, GA
Posts: 104
My Ride: 2001 325i ZSP
THx much!
QUEDRO is offline   Reply With Quote
Old 05-06-2010, 11:53 AM   #5
Registered User
Join Date: Mar 2010
Location: Johns Creek, GA
Posts: 244
My Ride: 2002 330 CiC
Double DIYs in the General and DIY forums? We love your pictures Delmarco, but a link to the one in DIY would have been fine.
Originally Posted by DCJodon View Post

ZOMG HALP! *click*

oh hai, i can haz part numbro for florr matz? k thanxz.
Bandersnatch is offline   Reply With Quote
Old 05-06-2010, 12:09 PM   #6
Registered User
Join Date: Sep 2009
Location: Brooklyn, NY
Posts: 277
My Ride: ///m3 vert, 05 MCS
awesome man

2005 ///m3 cb/cinnamon vert: weekends
2005 Mini Cooper S/jet black hardtop: daily
1988 e30 325ix/gray hardtop: gone
2002 e46 tiag 325ci vert: gone
burntass is offline   Reply With Quote
Old 05-06-2010, 12:22 PM   #7
David F
Registered User
Join Date: Jul 2009
Location: Austin, TX
Posts: 549
My Ride: 323i, 740iL, 633CSi
Using such a method to add refrigerant will work in a pinch, but the right way to do it is to evacuate the system and refill to the precise quantity of refrigerant indicated on the label under the hood. R134a is sensitive to quantity of charge and just reading pressures is not accurate enough. So, you might notice the difference in the deep south like Texas, Arizona, New Mexico, etc.
David F is offline   Reply With Quote
Old 05-06-2010, 12:28 PM   #8
OEM ///Member
Snik's Avatar
Join Date: Dec 2007
Location: SA, TX
Posts: 20,922
My Ride: IR M3 Vert.
cool write up. i think mine has a leak. anything over 92 degrees outside kicks it ass and it takes forever to cool
Originally Posted by rohde88 View Post
^^^ do you spend all your free time on two wheels?
The Snikster posted sexy wiminz here
Do you ride a sportbike?
Do you have a question about Jamaica? Ask?
Snik is offline   Reply With Quote
Old 05-06-2010, 01:21 PM   #9
zhp pilot
Falling from 14k ft.
zhp pilot's Avatar
Join Date: Apr 2008
Location: Charlotte, NC
Posts: 4,031
My Ride: is totaled :(
Excellent write up. You are truly one of the best DIY writers on this or any forum/technical source I have seen. I also enjoy reading your write up's for the entertainment aspect as well.

Just a comment on the max AC. On the typical car, the max AC button simply closes off the outside air supply to recirculate the air inside the cabin and increases the blower speed. Max AC takes advantage of the fact the air inside the car has less water vapor it in than outside the outside air. The lower the absolute humidity of the air, the easier it is for the system to remove the heat. If the blower speed is regulated only by climate control in your car and you never manually adjust it, you may have noticed it seldomly fills up the bars on the fan speed indicator. Therefore, to get max AC in an E46, just turn the climate control to recirculate and hit the fan speed up button until all bars are lit up. Voilą, max AC. For those that don't know where the recirculate button is, it's circled in the pic below. The left light is for auto, which I'm not quite sure how that works, and the right light is manual.

'04 Silbergrau Metallic ZHP 6MT

Last edited by zhp pilot; 05-07-2010 at 07:26 AM.
zhp pilot is offline   Reply With Quote
Old 05-07-2010, 01:46 AM   #10
Registered User
Join Date: Jul 2009
Location: Pittsburgh
Posts: 34
My Ride: 325i
Good stuff and perfect timing.
DFENSBMW is offline   Reply With Quote
Old 05-07-2010, 04:16 AM   #11
Registered User
Join Date: May 2010
Location: Tucson AZ
Posts: 67
My Ride: 325Ci
This is very much appreciated dude, I turned my A/C on for the first time today and noticed that it took it a while to get cool, and also once it was cooling on max a/c the air didn't seem as cold as it should have been...I'm going to pick up a can tomorrow...Thanks again
AW 325ci

Now that's an ASS!
AJs_325Ci is offline   Reply With Quote
Old 05-11-2010, 08:22 AM   #12
Registered User
Join Date: Feb 2008
Location: Philadelphia
Posts: 6,919
My Ride: M3 & ZHP
My car doesn't seem to be blowing as cold as usual, but the dealer did recharge my system pretty recently. It definitely still cools itself, so I don't think there's anything *broken*, but once it gets above 85 outside, the car definitely has a hard time keeping up with the heat.

Is there anything else I should check? Do you think it's possible that the dealer just didn't put enough?
TerraPhantm is offline   Reply With Quote
Old 05-11-2010, 09:12 AM   #13
Focal E46
Registered User
Join Date: Aug 2008
Location: Norfolk, Va
Posts: 1,875
My Ride: is a DIYer
Does anyone know what the exact PSI should be? or range?
Focal E46 is offline   Reply With Quote
Old 05-11-2010, 09:41 AM   #14
Registered User
Join Date: Mar 2008
Location: Vero Beach FL.
Posts: 2,249
My Ride: 99 328i. ZSP, ZPP,
Send a message via Yahoo to RockLee
Thats what I did, but I got a reusable hose and valve.

1999 328i Sport Package, Premium Package, 5 speed, Alpine white.
RockLee is offline   Reply With Quote
Old 06-12-2010, 11:57 AM   #15
Registered User
Join Date: Jul 2007
Location: East Coast
Posts: 309
My Ride: 323Ci
Send a message via AIM to GermnBlt
question: My parents had their 328 worked on and the guy left the cabin air filter housing off the car...And now the ac is blowing hot air only, will that affect the ac blowing cold air?
So, how many pounds you push

GermnBlt is offline   Reply With Quote
Old 06-12-2010, 01:18 PM   #16
Registered User
Join Date: Nov 2008
Location: Westchester, NY
Posts: 6,331
My Ride: 335xi Deep Sea Blue
Send a message via ICQ to delmarco Send a message via Yahoo to delmarco
Originally Posted by GermnBlt View Post
question: My parents had their 328 worked on and the guy left the cabin air filter housing off the car...And now the ac is blowing hot air only, will that affect the ac blowing cold air?
it shouldn't. but keep driving without the filter cover and it will result in debris getting into your vents eventually possibly clogging something important.
delmarco is offline   Reply With Quote
Old 06-12-2010, 04:32 PM   #17
Registered User
dmax's Avatar
Join Date: Aug 2006
Location: NJ
Posts: 23,709
My Ride: '99 328i 300K miles
Originally Posted by delmarco View Post
it shouldn't. but keep driving without the filter cover and it will result in debris getting into your vents eventually possibly clogging something important.
And everytime it rains, the air filter will get soaked and water will get where it isnt supposed to be...as in getting sucked into blower motor...hard rain sucked into vents...dropping down...not good. u need to replace the part
See me in June!
Ha! Ridgehill, Yonkers, June 8, 8 p.m. & Broadway Comedy Club, Sat., June 10, 6 p.m., hosting at the Comedy Cove, Springfield, NJ, June 16 & 17 for Joe DeVito, 9 p.m.
See Facebook for other shows and PM me if you can make one.

Please view this vid so it looks like I'm popular. Please! https://youtu.be/995gLmVEVZk

dmax on Facebook

Mangofy your E46!
dmax is offline   Reply With Quote
Old 06-13-2010, 12:31 PM   #18
Registered User
Join Date: Feb 2008
Location: Houston, Tx
Posts: 1,261
My Ride: 08 BMW 135i
thanks for the DIY! My car only starts blowing cold air when I'm already at my destination
jose325i is offline   Reply With Quote
Old 06-13-2010, 12:48 PM   #19
Registered User
Join Date: Mar 2003
Location: Bowie, MD
Posts: 124
My Ride: 2003 LSB M3
Good one! I noticed the "chill" and "shade" songs as well. Very appropriate.

Originally Posted by Focal E46 View Post
Does anyone know what the exact PSI should be? or range?
There should be a label somewhere on the system that contains this information.

**Also, as delmarco stated, some e46's do leak. This is usually because of the seals drying out due to lack of use. Although most people don't, its actually a good idea to run your AC once a month to keep the oil cycling through the system and seals conditioned.
03 M3Laguna Seca Blue
cunninglinguist is offline   Reply With Quote
Old 06-13-2010, 12:54 PM   #20
Registered User
Join Date: Jun 2010
Location: Texas
Posts: 10
My Ride: 325i
Anyway, very nice writeup, video & pic documentation. Also, good timing; +1 for general awesomeness.
NovaeDeArx is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON

All times are GMT -5. The time now is 02:33 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use