2004 3.0 ac delay
 

Hey gents!
I know there are a lot of threads on here about ac but I have read through nearly all of them and the ones that actually sound like my problem never come to a conclusion. So basically Im writing this to see if anyone can help me out becuase this ac issue is frustrating me!

Okay, so the ac doesn't begin to blow cold for about 15 mins after the vehicle starts. I looked first to the aux fan as most posts here point you in that direction. I noticed the aux fan does not spin when turning on ac, even when hitting the MAX button. the compressor however comes on as soon as ac is pushed. About 15 mins later however, the aux fan starts to spin and ac is cold. I checked V at fan and found a steady 14v, DME wire was around 40MV or so. So voltage is getting to the fan at all times. Also if I unplug the pressure switch the aux fan kicks on immediately and is on like super speed! So it seems like both fan speeds work (hi/low). But what else tells the fan to kick on or would cause the fan to not come on until the car is hot. Ohh, I forgot to mention that as soon as it works, you can turn the car off and on and it will still work. Once the cars sits for about 3-4 hours the ac delay starts all over again. I know there is a coolant temp switch, should I try shorting that out and see of it kicks the fan on? Is there any switches/sensors I can try? Relays?

Also, does this years model have a hi/low fan switch outside of the aux fan itself. I was told that the switch that interpretd the DME was actually built into the fan and if it went bad you had to replace the whole fan? But I have also read something about there being a mode switch near the expansion tank, which one is it?

If I have left any important info out please let me know. I will be monitoring this post closely as I am extremely desperate for a solution. Thanks in advance for any/all help!

Had the same exact issue on my 06 3.0. I traded it in before I had a shop look into it.

mine does similar, takes about 3-5 km before the a/c kicks in, i have found though that opening all the windows and sun roof seems to speed up the process.

im of the opinion that its a sensor thing, it wants all the hot air out before it starts the a/c up

Gone though this myself and did a lot of research on this.

It is the compressor, specifically the variable displacement control valve at the back plate of the compressor.

Theoretically it is possible to replace the valve if you can find one, but since my compressor overall had seen better days I just replaced the entire compressor assembly.

Really, I never thought it was the compressor because it seemed to be working, though it was a fan coming on issue because when it worked the ac is freezing. Not questioning you, just want to understand the logic, how does variable displacement control vavle affect the aux fan? the system in general? Thanks for the response!

I understand how you feel. I felt the same before I understood how the BMW AC system worked. I talked to a lot of techs and waded through a lot of vague info on-line to get a basic understanding of the system.

The E53 X5 AC system uses a variable displacement compressor. That means it does not depend on the compressor magnetic clutch engaging and disengaging a fixed stroke compressor to control refrigerant temps...a mechanical control valve inside the compressor senses pressure differential of inlet and outlet pressure within the compressor and alters the compressor stroke itself for optimal compression.

This kind of system has the compressor clutch engaged all the time as long as the AC is on and there is refrigerant in the system. This threw me off at first as I always assumed an engaged magnetic clutch means a working compressor. In these variable displacement compressors, this is not always true.

Do you have access to gauges? Hook them up and you will notice when the AC is cold, the low side pressure will be in the 30-40 range. When the AC stops cooling you will notice the low side pressure rising. And all that time you will notice that the magnetic clutch remains engaged.

In a standard fixed stroke compressor, no cooling plus elevated low side pressures indicate a worn out compressor. It no longer compresses the refrigerant. It indicates low/loose compression.

In this case it cant be a worn out compressor as there is good compression as evidenced by the cooling and verified by gauge readings. It just happens to be intermitent.

In variable displacement systems intermitent compression usually means the control valve is not working as it should. There is no compression when there should be compression.

The fan is not working because the pressure switch that turns it on does not see any pressure in the system, because the compressor is not compressing...the fan operation is a symptom and not a cause.

When the compressor starts compressing, pressure rises in the system and the fan then operates normally.

I hope that made sense.

Makes perfect sense! Thanks so much for the response. Finally I feel like I'm getting somewhere. Surprised there are not more posts of this type of situation? I hope that replacing the compressor is a reasonable DIY'er.
Do you happen to know if I change it myself, are there any other parts that I need to or should be changed at the same time (belts, o'rings, etc)? Thanks again brother!

No problem at all, glad to help!

Yes, I am surprised I did not find any technical info on this problem in any BMW forum I went to.

I found more info on this problem in a Chevy forum somewhere, of all places.

Dont worry, it is a pretty reasonable DIY, a half day or so job.

Nothing really needs replacing along with the compressor unless during the pulldown you notice any worn or broken parts.

I'm having a hard time posting now, this page keeps closing while I type a reply, will post an outline of the job in a bit.

I watched the tech do the compressor replacement and it was not all that hard.

First off you will have to go to a shop to evacuate and collect the refrigerant, otherwise you will have to dump it to the atmosphere, which is bad according to the EPA. ;).

My tech removed the cover underneath the front bumper so he could work from the top and bottom.

There is a rubber pipe from the engine to a cannister behind the headlight, looks like an EGR thing, which you should remove. The compressor was removed from the top so this line was in the way.

Remove AC belt, the belt tensioner is leveraged out of the way by inserting the appropriate sized allen wrench into the front of the tensioner pulley and just pushing the pulley in the appropriate direction.

Then you can unplug the harness and start removing the block fittings on the compressor.

Then you can start removing the compressor mounting bolts.

Then move the AC lines out of the way and you can pull the compressor out.

As mentioned it came out from the top.

Pretty much reverse to install.

Do take a look at your belts and the system o-rings while you are at it. I just re-used all of mine since they were still in good shape.

I think the 04's use a Calsonic Kansei CSV 717 compressor, the earlier models use a Denso. My 04 3.0 had the Calsonic.

Thanks again brother, I'm gonna give it a try! I will make sure to post any relavent information after the job.

Anytime, good luck and let us know how it goes!

Okay so I punked out a little and decided to take it to a indy to get fixed. I just didnt want to deal with it all and i really just need it fixed correctly. So when I get there he says there is nothing wrong. I told him ofcourse there is not right now because the car is warmed up. I explained how the first 15 or minuites after the car is cold is when it doesn't work. So basically, since I didnt want to sit there for 5 hours and wait for the car to cool down, he couldnt really do much because everything tested good and the ac was frezzing. I explained to him about the variable displacment control valve but he said he couldnt tell cause it was working. He cautioned me about just replacing the compressor if I am not 100% sure. He said he would do it though if I twisted his arm. I decided to wait.

g300d-
After reading your post again I noticed you used the word "intermittent" to describe you ac. This would tell me that it works, then suddenly stops, and comes back on again with no rhyme or reason, is this correct? My problem I wouldnt neccessarily call intermittent. Once my ac is working it stays working until the car sits for a few hours and cools down. When the car is cold, no aux fan and no ac, when car is hot fan is spinning and ac is cold. Do you still think our problems are the same and therefore replacing compressor would work? Thanks again

What you are experiencing now is exactly what I was going through in the beginning.

Then it started to become intermitent, it would cool after the engine warmed up, then it would stop cooling, then come on again, with no apparent pattern.

Eventually it took longer and longer for the AC to start cooling, till it hardly would work at all.

And all that time the compressor clutch was engaged too! Really threw me off.

I remember that the day I decided to replace the compressor I started the car to move it to the service bay and the damn AC started working, I almost lost my nerve to replace the compressor right there!

Maybe you could leave the car overnight with the indy so he can see the problem first hand in the morning?

Here is a good article on variable displacement compressors and a description of the problem:
http://www.aircondition.com/tech/get...9WYWx2ZXMucGRm

So the starngest thing happenned. I was just ready to make an appointment with my indy when.... my car wouldn't start. I got a jump and it started immediately. I figured i must have left an interior light on or something. I drove around for about 2 hrs and turned it off. 3 hrs later it wouldnt start and i needed a jump again. I went to have the battery tested and they told me it was bad, not enough CCA (they didnt tell me the number it did have). replaced the battery and everything worked fine.

Next day I start my car and within two minutes ac is blowing cold!. it has been two days in a row now and ac is working without any long delay. still takes 2-3 minutes but not 15. and doesnt blow steaming hot air even when not fully cold. Could a low battery have caused my ac issues? is this possible?

My 03 3.0 X5 has exact the same A/C delay problem. So you say replacing the compressor will do the trick? Do you know how much part/labor cost?

Marine, the compressing action of the AC compressor is not electronically controlled as I understand it. The clutch is engaged and stays on when the AC is on, but the compressor internal control valve determines whether the compressor actually compresses refrigerant.

I know how you feel buddy, everytime the AC happens to cool I would say to myself, maybe it was this or that, but in my case eventually it reached the point it was not cooling more than it was cooling, and I replaced the compressor.

What you are experiencing now seems to be the "intermittent cooling" I went through, LOL!

I really do understand your hesitation as this is a problem/diagnosis that involves major work and an expensive part replacement to verify. I suggest that if your AC puts out cold air most of the time, just live with it in the meantime.

As I understand it, the valve is not a part that either works or doesnt; it can malfunction intermitently, or totally stop working. In my case, it stopped working often enough that I felt justified in taking the chance to replace the compressor assembly. AC was back to normal after that, which confirmed my diagnosis.

Lynhnn, I am not sure if your car has the same compressor as mine, my research indicates pre-facelift cars use Denso compressors as opposed to the Calsonic Kansei mine has. Labor should be about 3-4hours of work plus refrigerant costs at your favorite indy.

Sorry I haven' t been back to update. Well it seems I was excited about nothing. It lasted for two days but now it is back to the long delay. Infact the delay has seemed to get even longer. I'm gonna go ahead and replace the compressor, just waiting to find a good time to get it done.

g300d, after I read your post it always encourages me that it is the compressor. I get amped up to replace it but I seem to lose my nerve. I think I'm going to print out this thread and read it in the indy parking lot so I actually go through with it LOL!

This may be a dumb question, but have you checked the freon level? Mine was doing the same thing about a week ago and when I took it down they said that I was a pound low on freon. They also told me that this is a normal function of the AC on these cars, for the AC to delay coming on when the freon level is low. Mine now works fine since I got the freon topped off.

Yes, i had my freon checked. I even had it evacuated and refilled to no avail. 1lb low, my X only holds .97lbs? Also, I'm no expert but from what I have read it is sometimes normal for the variable displacement compresor to have a slight delay while excess liquidified gas and stuff is pumped out of the compresor but my delay is quite long and definitely not normal. Thanks though for the input.

I tell ya Marine, I was at the shop to get the compressor replaced, moving the car to the lift when the darn AC went cold and I almost lost my nerve right there! :-P

I myself didnt do it until the delays got so long that it would hardly go cold anymore and there was nothing to lose anyway.

Let us know if and when you go though with it, we are the first people talking about solving this problem online that I know of, I know because when I was going through this there was hardly any info on the BMW forums.

Just read through this thread and thought I share my a/c nightmare. So my a/c would have the same fooking delays explained here be OP and other posters. Sometimes the "delay" never came and I would go a whole day without a/c. Took the vehicle to a BMW dealership to get it diagnosed and after 2 hours of sitting in the waiting area, service adviser says my compressor is shot and its a $1600 repair bill with parts and labor. I ran from there with all four windows open. So now that I knew that it was the compressor because BMW said so, I purchased a reman'ed one and got it installed. To no avail, a/c still wouldn't work. Took the vehicle to a recommended shop in Jersey and after a diagnosed I was told that the climate control panel inside was not working. Got a used one and left the shop within an hour with freezing cold a/c. Drove the vehicle for 3 days with awesome a/c and on the fourth boom, a/c would not turn on again. I call the shop and explained that the shit went crazy again so I bring the vehicle back. It has been almost 2 weeks today and my vehicle is still in this shop. They have tried everything, even installing the old compressor that BMW said was shot (it wasn't). The owner of the shop has now taken my vehicle as a project because he says he has never seen anything like this. All components of the air condition system are working, and a/c works but after driving the vehicle for 20 minutes with a temperature gauge in the vents he notices that the temperature rises from 30 degrees to 70 and compressor stops. The compressor kicks back in after 10-20 minutes and this continues to happen. Finally today I call and hear the words/get the answer I was hoping to get... We have found the problem. There appears to be a short in the DME circuit that controls the a/c system. I need a new DME. Looking at a re-manufactured one now because a new one it out of the question.

I confirm with my car that

Sometimes the "delay" never came and I would go a whole day without a/c

Cisc0, that indeed sucks a big hairy meatball!

I would have done things differently in your situation though.

First thing I check when AC cuts out is refrigerant and compressor clutch operation.

In your case, with refrigerant in the system and the compressor cutting out it would definitely be pointing towards an electrical problem first, either with the compressor clutch itself, the AC computer and its related sensors, or DME.

It would still be a nightmare narrowing it down to which electrical system is shutting off the compressor though, and why.

In our case though the compressor clutch is always engaged, but no cooling.

That particular variable helps narrow own the possible causes in this particular AC system type.

g300d,

You'd think the professionals @ the BMW dealership I went to would follow proper diagnosing techniques but they were just looking to rape me as thy usually do. Good thing is that it is finally sorted out and I get I return the compressor I purchased.

This is my first post in an attempt to help those who have the AC delay problem like I did on my 06 X5 3.0; which I spent a couple of weeks before resolution. Bought used w/ 75k miles 8 months ago and always had my delay after the car was off for many hours (like overnight or after a 12 hour shift), the AC would blow ambient temp until I was down the road a couple of miles then instant cold AC.

The problem ultimately in my case occured when the hi and the low sides of the compresoor equalized, which takes many hours once the AC was off (this is norm). Even after a few hours when the pressures were not yet equalized the AC would immediately blow cold and stay cold even at idle. I verified this renting gauges from Autozone and was able to duplicate the problem by shutting off the AC (after it was working) and slowly bleeding the high to the low side until pressures were equalized. Then turning on the AC (comp engaged) the pressured stayed equalized (no cold) until either I reved the engine enough to cause a slight difference in pressure then the presssures would instantly move to norm high and low.

My take on it (not being a mech engineer) is that it is something in the comp similar to a hung open or closed suction or discharge valve, or it is something else not seating or resetting until there is enough difference in pressure to hold force on it to work. The discharge line of the comp stays ambient to the touch so no vapors are leaving the comp at this time.

Like most everyone, I thought it was the fan, pressure switches, freon level etc. I changed out the PCV on the comp itself and that did no good. I bought a remanufactured comp and installed myself and only changed the dessicant dryer media, prob solved. Guess you can say good news is that the comp did not lose pieces (no major damage) so the repair did not include the expansion valve and condensor and flushing as would be required for warranty usually when installing a new comp.

Just to note, when I received my remanned comp, I could hold my finger over the discharge, turn the comp by hand and pressure would build behind my finger. When I removed my problem (orig) comp it would not build pressure by a hand turn.

Not the answer some wanted but hope this helps.

Hey Geauxfast, it looks like you had the same problem I did, the variable displacement control valve in the compressor. When this sticks open, there is no compression, and thus no cooling.

Just to note I did change out the PCV that adjusts piston stroke to no avail. I am thinking it is the discharge or suction "check" valve if one exists or whatever it is that seals the vapor in to allow compression (that which is in all compressors). The PCV sends either high or low side to the piston/wobble plate crankcase side to vary piston stroke. I thought I later read that at worse the piston stroke would be reduced to 20% so I am thinking a sticking or failed PCV will not completely prevent compression only screw around with your pressures by mis-adjusting the piston stroke. My problem was consistent and never intermittent so I don't know if "sticking" would apply. I also early on shot oil in the system to unstick whatever might be sticking and no luck there either.
I may gut the comp and report any findings.
BTW thanks for the thread.

Interesting theory, would be interested in whatever you find out.

I gutted my orig csv717 comp and nothing is evident, no shavings, scarring, burnt, worn etc, only a couple of scratches on the wobble plate. In studying the pressure passages I can draw a few conclusions FWIW and not being a mech engineer. Again I am looking for a reason the comp would turn internally but not compress initially.
The replaceable PCV in my opinion was not the culprit because its opening is far smaller than any one suc and discharge valve of even one piston to allow total bypass. I did however change it out to no avail. Also when all pressures are equalized at startup it could not create or uncreate a differential on its own.
The suc and discharge check flapper valves were not stuck open because it took hours for the high and low sides to equalize when the car was off. Besides there are 5 pistons give or take and a suc and discharge valve for each and no single alone valve for all. So even if one was stuck open the others combined would over take to create a differential I believe.
The wobble plate when spun by hand was flush causing no piston stroke. The wobbles plate is attached to a spring and the shaft has a half disc which I presume to be an offset weight so under fast revolutions of the engine compared to a hand turn, the offset weight causes the wobble plate to tilt for initial piston stroke. I would think that since my problem was consistent and only corrected under acceleration there could have been a problem with the wobble plate being under too much spring tension or that the shimming washers were not set right or wore if tolerances were critical.
So I did not find the exact problem only a solution. A mech engineer specializing on the subject would be helpful, however if I can help you in any way shoot me a line.

This thread has been a very interesting read, however, I think the problem I am experiencing is a little different.
When I turn My AC on, it gets cold ok, but it seems to put the car into limp mode or something. I narrowed it down by chance to the AC.
The car runs fine until you turn on the AC. It starts to misfire. Sometimes almost straight away, sometimes it may be 5 or 10 mins later.
No lights or warnings come up, just no power and a car that feels like its running on 5cyl.
Just today I thought I would try it and as soon as the engine revved over 2500 or so, I would get a terrible rattle out of the compressor. So it sounds like my compressor is shot, but I dont want to spend $1000 replacing that to find it still goes into limp mode.
Sorry if its a little thread jacking.
Ben.

Geauxfast, thanks for posting that, it's additional food for thought. It seems it's just better to replace the compressor when these symptoms pop up. It doesnt seem worth it to go repair it.

Benvette, that sounds like there could be an electrical problem (misfires) aside from your compressor, and they might be completely unrelated. I would probably start with checking for error codes. Good luck!

HOLY THREAD REVIVAL BATMAN!!! I have an 05 3.0 with this same issue. I know for certain the clutch is engaging, and it's spinning the compressor. I want to try the compressor control valve just for shiggles, but I am finding zero information on how to do it. I've seen those who said they did the valve (and it didn't help) but not how they did it. If anyone has done it and have a few pointers for me on the process or what to look for, I'd greatly appreciate it!

If there's interest in it, I'll do a proper write up w/photos when I do it. I just don't want to be completely blind when I start this.

Lol yeah I I've had this truck for that long!

Check post #15 of this thread, there is a PDF article of the teardown and valve replacement of a variable displacement compressor with pics.

The DME not sending the right signal can easily cause the grief described and the "refurbish" solutions usually mean reflow the bad solder joints.

I'm having a problem with my O2 sensor heaters and it's a fair chance there are some bad solder joints in there.

The aux fan has voltage applied always and a signal is sent directly to the fan that turns on a transistor. I don't know if it's a high signal or low signal for on or off it sends PWM for more speed but that seems how it works I don't see multiple windings.

I'm in the same boat. I've given up on replacing compressor as long as it works with the delay for now. Not sure until when.

If you have the Calsonic Kansei compressor than you have the variable displacement compressor. Most likely the solenoid that control the the variable diplacement of the compressor is not working properly so the compressor never get to the point that it is actually pumping refrigerant through the system at the very beginning. Once the engine had turned the compressor after awhile the compressor kicks in and enough refrigernt is flowing that the system is working. Never had any trouble with my fix displacement Denso compressor all the years that I own my X.

I'd choose to have the fixed one but as I know after 2002 the only compressor available is variable displacement design. It really has no stutter or change in the rpms when you switch it on, which is good and the cooling is really good but that solenoid valve just is so unreliable. If it is the problem is really the valve itself, not something else in the compressor.