AC

[Silverti]

Hi all, i've only had my 318 a day so go easy on me :wink:

Been looking over the forum the last few days and some really interesting stuff here, and a lot of guys obviously spend a long time under the bonnet of these things...

Basically, i've never owned a car with air con before so i don't really know what the expected performance should be like, i.e. how cold should the air be? (sounds stupid i know).

When i switch it on the air does seem to cool slightly but i'm not sure if it is just me thinking its happening. Driving around today it was only 17 odd degrees centigrade outside and the car was just about being kept cool with AC on full cold and fan on 4. Doesn't sound right to be but i haven't got a clue where to start. I'm pretty handy with a spanner but have never done any work on AC before. Any ideas?

Cheers
Silverti

[Silverti]

Update to this.......

Had the pressure checked today and it was 0 psi and the tubes were at engine temp rather than ice cold as i've been told they should be.

So next step.

I'm guessing theres a leak in the system somewhere. Is there anyway to find where a leak is or could it be anything else?

Edit: I have the car booked into a garage to look at it on monday but would prefer to get it sorted myself if i can.

Cheers for any help.

Silverti

[ti-billy]

yes, u can put a dye into the a/c system, and check it with a black light and trace the dye trail back to the leak, kinda hard to do this without an hvac machine and knowledge of a/c system tho

[b.u.ti-ful]

In my area these days AC is best left to the pro's.

They have taken the charging kits out of the stores.

[Silverti]

Cheers guys,

Just seen on another thread that the compressor won't kick in if the system doesn't have any pressure, so i'm not going to beable to find out whats wrong without (possibly) wasting a £50 can of refridgerant to see if the compressors going to start spinning.

I think its a job for the garage on monday and see what they say. They should have all the equipment to pressurise the system and see whats going on.

I'll keep you updated.

[J!m]

You are doing the right thing.

The dye trick works well, and the garage will most likely do that. Also, if the system has had a leak for quite a while, the desiccant canister should be replaced as well.

The leak is most likely from one of the o-rings, but it could be a cracked component as well. Let them check, but make sure they let you know what the problem is before proceeding with the repair! A new condenser or evaporator is quite expensive, and can easily be obtained at the bone yard for much less. If it IS just an o-ring, let then fix it up and you'll be chillin' in no time!

PS if you use the recirculate button with the A/C you will get colder air as it re-cools the interior air rather than cooling outside air. According to the manual, you should not run this way for long because you run out of oxygen in the car!:eek: I don't know about THAT, but for what it's worth...

[Silverti]

Thanks Jim,

I'll make sure they know to ask me before they do anything.

If its not a quick cheap fix it can stay broken for a while and i'll source some parts. Got a local BMW breaker a short drive away who have a few e36's in should i need them.

Death by recirc, that would be a new one....:confused:

[J!m]

Death by recirc, that would be a new one....:confused:


Odd, I know, but as they say "Truth is stranger than Fiction".

So, just sending out that disclaimer!

Another relevant quote:

"We don't make it up, we just read it".

[Silverti]

Just been out looking to see if the car has a factory alarm (i only recieved one key with it so need to get another key cut and a fob if it has an alarm / remote locking).

Anyway...is the pipework infront of the rad is to do with the AC? If so this pipework is loose and seems to be held on with cable ties :eek: so could be the cause of the problems. Also the pipework is quite rusty, can't tell whether its rusted through though.

[xxxJohnBoyxxx]

If you have a charge kit you can put a little Freon in there and see if it's a big leak and locate and fix or replace the parts. It can be complicated.

Any system that has been down for a while or open to air like yours has since it was at 0psi should have a new dryer installed and vacuumed to 30hg vacuum to remove all non-condensable in the system before a new charge is added.

Since you don't have a good knowledge with the system it is best to take it to a repair shop. It can get expensive so be ready to shell out some bucks, stay away from the dealer and take it to a local shop that is know for not ripping people off.

Better yet find a friend or someone on the board that knows what they are doing. If you lived close to me a $1,000 job would cost you parts only so less then $100 or maybe $20 for just Freon and we would repair the leak for free...

That's the facts man

Best of luck, John Smith

[Silverti]

Cheers for the info John,

I'll see what the garage says on monday.

My old man's a mechanic so he can do the work on the cheap for me, not seeing him until xmas though, but it will save me mega bucks...

[Silverti]

Right took it into the garage this morning...

They put a vacuum into it and it held so they filled it with refridgerant and some dye and it seems to be holding the charge for the time being and no leaks were evident with the uv light.

Going to leave it for a few weeks and get it pressure tested and a going over with the uv light again to see if its losing charge.

Cheers for all the help with everything guys
Silverti

[Silverti]

Its a long time since i started this thread but finally got the AC sorted over xmas.

After getting it filled it proceeded to leak all the gas over a 2 week period. It was leaking from what looked like the pipe from the condenser to compressor, so i had that and the pipe from the condenser to drier both changed and filled again. This time it leaked out within a day (i don't know why the garage filled it up, it couldn't have held any pressure.....).

The garage said that the connector on the condenser was corroded and flaking and the pipes wouldn't seat probably (again why he filled it i don't know) which was where the leak was coming from. So over xmas i got round to finally getting a new condenser and drier, fitted them myself and had the thing tested and filled and no leaks so far.

So after many hours and more money than i care to think about i now have working AC....:biggrin:

Cheers for the help while i was trying to figure it out guys. I now know a lot more about AC systems than i did before.

[curtdfw]

this is somewhat late, but this thread on bimmerforums has a nice and simple explanation of A/C systems:

http://forums.bimmerforums.com/forum/showthread.php?t=573174


What it doesn't answer is my question about the A/C switch on the dash. On my new (to me) '96, the A/C light doesn't come on at all when the button is pressed. Fuses are all OK and have been reseated. I understand that, as a safety measure, if there's low or no pressure in the system it won't start up, but does that also mean that the light will not come on?

I'm thinking of installing a can of refrigerant to see if it behaves any differently, but thought clarifying the switch light question would be a start.

[J!m]

The high and low side should be checked; but to answer the question, yes, if the pressure is low it won't come on and (if memory serves) the light will not come on unless the system is operating correctly.

Also, bear in mind that if it was open for any length of time (more than an hour or three) the dryer will need to be changed as well.

[curtdfw]

Well, I've put three 12 oz cans of R-134 into the system and I'm getting up to 40 psi low, 160 psi high with the barest amount of cooling noticeable in mild (~75F) weather. The next day they're down around zero. I tried some red dye, and can't find any indication of leaks, or obvious stuff like dirt accumulations around fittings etc.

What more or less hidden connections can I be missing?

[pdxmotorhead]

You usually need a UV light to see the leaks, its not visible with the naked eye.

You have to use a full on professional style 2 gauge system on the BMW ac unit, the correct amount of R134 is really sensitive. Put in a ounce or two too much and you'll lock the compressor. It also runs at a funny pressure level compared to other R134 systems. If I recall the high side is like 30 lbs lower than a chevy or ford system.

There was a TSB on the expansion valves on 90's BMW's for noise and improper operation.

Dave

Dave

[curtdfw]

Thanks - I have a gauge set (though admittedly not pro grade), and I chose the red dye because it allegedly didn't require a black light, but I've been fooled before. So where are they hiding that expansion valve?

How're things in Puddletown? Spent most of my adult life there, the last ten years with my '74 2002. I miss the beer...

[pdxmotorhead]

Freeking WET.... I am ready for any sun...

I use a Harbour Freight set, it does the job... The expansion valve should be in the manual, its a copper gadget with a coil of tubing ,,, it howls occasionally when my AC kicks in.

Dave

[curtdfw]

The Bentley E36 manual (which seems to deal mostly with sedans & 6-cyl cars) shows the expansion valve behind the glove box - to your knowledge is location the same for the ti? Looks entertaining to get to...

[xxxJohnBoyxxx]

You have a good differential on your pressures. Have you done a touch feel test? Is the high side super hot leaving the compressor? Is the low side going in the compressor cold? Is the high side fromthe condensor cooled off to a acceptable temp before hitting the expansion valve?

Did you pull a fulll 30hg vacuum and hold if for 30minutes beforeyou charged the system? If not you might have a small amount of moisture in there which causes a freeze lock when the freon goes through the expansion valve and evaporates...

If your touch feel test passes then you mught have a situation where the A/C is coolingbut your stck in half heat half A/C so your not feeling the cold air...

Just some ideas

[hotmilk400]

atleast you do not have problems like mine.

the first summer i had it, the AC worked.

the 2nd summer, it did not work, and would blow fuses

the 3rd summer, it worked even better then the 1st summer (i did nothing to it)

now this summer, it wont work, and the fuses are okay??

haha

the Green light on the switch even light. i think i have a short on the AC compressor or something, but i am not sure why it works 1 year and not the next..

ehh.. i don't have time for AC problems.. life is to short, and the shops want to much. =/