E36 - What the hell is this frozen pipe! [TW]Fox?

ChocolateStarfishRammer · 27 Jul 2012 at 19:39

What the hell is that white pipe!? And why is it near on frozen???

Its hot outside!

Backstory:

I had both Engine Mounts replaced on Thursday and after picking it up ive done about 60miles and it all seems fine.
For a few weeks, the Temperature Control Unit (bit in the console that you change the temp on/fans, aircon on/off etc) has not been working, the power to it keeps going on and off so one minute itll work, the next it wont. Sometimes itll still be blowing the fans but the unit will look like its turnt off and unresponsive to button pressing.

Onto problem at hand, I drove casually for about 15minutes where at the start there was an odd sound that was like a motor struggling to turn over or moreso that slight sound you hear from the power steering pump when you go hard lock.. just like that... which is not a usual sound.. but didn't notice it effecting anything.

I pulled up (destination) and left car for about half hour. When I came back I noticed a small puddle trail underneigh, I checked best I could and it was coming from almost exactly middle of car dripping down. Checking the fluid on the ground it looked, smelt and tasted like water.

I decided to drive and just watch temps.. Temps stayed absolutely fine. I pulled up again and decided to have a quick check under bonnet and thats when I found that pipe! Initially I thought someone had painted it at the garage but upon touch, it was freeezing cold! Scrated with finger nail, it was like scapping the freezer off. Why the hell is it soo cold!? Im guessing this has something to do with the duff temp unit but it wasn't blowing cold into the car.. Another thought was that maybe the garage knocked something when changed the engine mounts!? Also, had a little look at this point and it looked like the dripping underneath had stopped.

Thoughts would be great guys!

PhillyDee · 27 Jul 2012 at 19:41

Aircon pipe.

/thread.

Also, Aircon also dehumidifies, and the water has to go somewhere. It drips out the bottom exactly how you described. As for the rest, I 'unno.

Jonnycoupe · 27 Jul 2012 at 19:44

It's the aircon pipe, moisture in the air is condensing on the cold pipe surface whilst the liquid in the discharge tube is expanding into a gas and absorbing surround heat as it phase changes.

Hence ice.

[TW]Fox · 27 Jul 2012 at 19:44

Whats with my name in the thread title, I'm hardly the only person in the world who could answer a question

ChocolateStarfishRammer · 27 Jul 2012 at 19:48

PhillyDee said:
Aircon pipe.

/thread.

Also, Aircon also dehumidifies, and the water has to go somewhere. It drips out the bottom exactly how you described. As for the rest, I 'unno.

Ahh right ok..

Jonnycoupe said:
It's the aircon pipe, moisture in the air is condensing on the cold pipe surface whilst the liquid in the discharge tube is expanding into a gas and absorbing surround heat as it phase changes.

Hence ice.

Ok that makes sense! Just its baking hot here and it looked soo out of place!

Thats completely normal then? Just me panicking? lol

[TW]Fox;22437592 said:
Whats with my name in the thread title, I'm hardly the only person in the world who could answer a question

Because every time I see anyone with car issues, especically bimmers, BAM theres fox with his Hammer of Knowledge

Greebo · 27 Jul 2012 at 19:53

[TW]Fox;22437592 said:
Whats with my name in the thread title, I'm hardly the only person in the world who could answer a question

Cause if it;s BMW related, you will gets lots of people with different answers until you arrive with

"Actually I think you will find that they only did that on the LHD Exx model between March 2009 and June 2009 but in the UK they fitted the Nxx engine which had a modified rotary wankel air compressor which is prone to icing problems and in 2011 there was recall for it so contact your dealer and get it done"

Clarkey · 27 Jul 2012 at 19:56

I'd have thought it was pretty obvious to anyone that it was AC, why would anything else be cold in the engine bay?

ChocolateStarfishRammer · 27 Jul 2012 at 20:00

Greebo said:
Cause if it;s BMW related, you will gets lots of people with different answers until you arrive with

"Actually I think you will find that they only did that on the LHD Exx model between March 2009 and June 2009 but in the UK they fitted the Nxx engine which had a modified rotary wankel air compressor which is prone to icing problems and in 2011 there was recall for it so contact your dealer and get it done"

Haha! Exactly!

Clarkey said:
I'd have thought it was pretty obvious to anyone that it was AC, why would anything else be cold in the engine bay?

Because as explained... Technically I cant even turn the A/C on at the moment.

Westyfield2 · 27 Jul 2012 at 20:01

Even my mother could identify the aircon under her bonnet!

ChocolateStarfishRammer · 27 Jul 2012 at 20:03

Westyfield2 said:
Even my mother could identify the aircon under her bonnet!

Well I had just dropped her off so she wasn't there to help.

sigma · 27 Jul 2012 at 20:06

Greebo said:
Cause if it;s BMW related, you will gets lots of people with different answers until you arrive with

"Actually I think you will find that they only did that on the LHD Exx model between March 2009 and June 2009 but in the UK they fitted the Nxx engine which had a modified rotary wankel air compressor which is prone to icing problems and in 2011 there was recall for it so contact your dealer and get it done"

Lol.

SDK^ · 27 Jul 2012 at 20:07

It's the heatsink to cool the overclocked CPU in the ECU

RJC · 27 Jul 2012 at 20:08

The suction pipe is far to cold for std aircon in the car in this weather, I would suspect sweating but not ice. Is there actually air flow going accross the cooling matrix?

I would suspect your slugging liquid back to the compressor! :eek:

Firestar_3x · 27 Jul 2012 at 20:13

ChocolateStarfishRammer said:
Because every time I see anyone with car issues, especically bimmers, BAM theres fox with his Hammer of Knowledge

Fox know lots about BMW's, but vs many of us when it comes to actual car maintenance and fault finding he's positively spanner shy.

Greebo · 27 Jul 2012 at 20:16

Firestar_3x said:
Fox know lots about BMW's, but vs many of us when it comes to actual car maintenance and fault finding he's positively spanner shy.

Burn the heretic!

ChocolateStarfishRammer · 27 Jul 2012 at 20:26

SDK^ said:
It's the heatsink to cool the overclocked CPU in the ECU

Haha!

RJC said:
The suction pipe is far to cold for std aircon in the car in this weather, I would suspect sweating but not ice. Is there actually air flow going accross the cooling matrix?

I would suspect your slugging liquid back to the compressor!

Ohh dude! just when everyone has got me chilled out you come along with things like that!

Thoughts on this anyone?

RJC · 27 Jul 2012 at 20:41

ChocolateStarfishRammer said:
Haha!

Ohh dude! just when everyone has got me chilled out you come along with things like that!

Thoughts on this anyone?

Sorry to put a downer on things, but you need look deeper at the refrigeration system.

To get a suction pipe cold with ice like you got, you usually only see on low temp systems running cold stores and freezers.

If you were not flooding liquid back, your suction pipe could be around -2 deg (roughly), if you had 5c Super Heat the boiling point of the refrigerant would be -7 (1.2 bar) (assuming your on R134a) meaning your heater matrix would become a block of ice especially in this humid weather and block air flow which would mean the refrigerant would not boil off in the heater matrix but start absorbing heat from the suction pipe.
and you will see the ice your getting.

I wonder if the garage were supposed to remove the charge before commencing work, but did not and ended up recharging it again so you have double the charge.

ChocolateStarfishRammer · 27 Jul 2012 at 20:46

RJC said:
Sorry to put a downer on things, but you need look deeper at the refrigeration system.

To get a suction pipe cold with ice like you got, you usually only see on low temp systems running cold stores and freezers.

If you were not flooding liquid back, your suction pipe could be around -2 deg (roughly), if you had 5c Super Heat the boiling point of the refrigerant would be -7 (1.2 bar) (assuming your on R134a) meaning your heater matrix would become a block of ice especially in this humid weather and block air flow which would mean the refrigerant would not boil off in the heater matrix but start absorbing heat from the suction pipe.
and you will see the ice your getting.

I wonder if the garage were supposed to remove the charge before commencing work, but did not and ended up recharging it again so you have double the charge.

Not gunna lie.

I dont understand a word of that

RJC · 27 Jul 2012 at 20:54

ChocolateStarfishRammer said:
Not gunna lie.

I dont understand a word of that

Well, in this weather to get a suction pipe that cold under normal operational conditions I would suspect your car to be around 2c with your occupants wearing wooly hats and scarves

But with the car cabin at reasonable temp, around 20 - 25c the suction pipe should be cool to touch and with if humid outside have some condensation.

With your pipe being that cold and noises from the engine makes me think something else is wrong, i.e. the cooler matrix fan is not operating so the liquid refrigerant is not boiling off in the matrix and continuing down the suction pipe, hence the frost.

Sin_Chase · 27 Jul 2012 at 21:00

It's for the optional Mr Whippy machine in the boot, have you not seen it before?!