Oil Leak 3BG: Causes and Solutions

Hello!
Yesterday, I discovered an oil leak under the car. It's leaking on the passenger side, between the wheel arch and the "underbody pan," so it's quite far forward.
The oil is crystal clear (or very slightly yellowish), very thin, and has a very mineral smell (it reminds me of my Märklin HO trains). I suspect it's from an air conditioning system or a gearbox.
I can see the gearbox from below, without needing a lift, using a mirror. The end of the gearbox/aluminum block is dry. Therefore, I strongly suspect a leak in the air conditioning system or the compressor.
However, I have absolutely no idea about it, and I'm completely in the dark.

All easily checkable fluid levels, including the power steering, water, and engine fluids, are normal and definitely have different colors and smells.

The day before, I had replaced the double temperature sensor, located at the rear, underneath the cylinder head. In the process, some coolant (G12) leaked out, which I replaced.
Ich denke nicht, dass es einen Zusammenhang mit dem o.g. It's leaking.

VCDS tells me that no errors can be found electronically.

Does anyone have a suggestion? Otherwise, I'll have to go to a workshop.
Thank you in advance, haithamina.

Hello,

If I'm interpreting this correctly, the fuel cooler is located on the front right side of my 3B. If that's also the case for the 3BG, it could potentially be a diesel fuel cooler.

Transmission oil has its own smell, but it usually looks more honey-colored (the types I'm familiar with for the gearbox). And since my air conditioning is currently running, I can add that I haven't noticed such a distinctive smell with the compressor oil.

Bye.
peace

P.S.: Removing the underbody tray can also be done with a jack (NOT the flimsy one from the emergency kit!), and for added safety, using an additional support stand is a good idea. Lift it up on one side and secure it, and then there's enough space.

Hi pax,
That's not a bad idea!
However, this stuff smells different. I think freshly tapped diesel certainly smells different from diesel that has been stuck in or on the bottom of a container for a while and has lost some of its more volatile components...

By the way, after replacing the dual temperature sensor, I also performed an actuator analysis (is that what it's called?) of the air conditioning system using VCDS, with the ignition on and the engine off, because I recently received a warning about a flap malfunction. The self-test initiated by VCDS caused the fan to start, but then not much happened, and I aborted the test after waiting for several minutes. I tried the whole process twice, but the self-test was unsuccessful: "Function currently not available."
haithamina

Check the fuel filter to make sure the water separator, if present, is securely attached.
Do you have a stand mixer or a hand mixer?

Hello everyone, hello readers, and hello those who are answering.
The solution to the "puzzle": the classic!
A four-legged creature has gnawed on both the air conditioning hoses (heat exchangers) and the BKV (waste heat recovery) system! Since everything was dry after the last trips, and I had started to believe in the self-healing properties of the 3BG, it was good that I put him in the .
The main water pipe wasn't connected yet... the air conditioning was working, but it was clear that so much had leaked out that it wasn't dripping anymore.
370 euros including materials and labor for the end consumer! Great! At that price, a subsidized dental treatment program with a patient contribution probably doesn't make sense.
haithamina

Apparently, the Dossenheimer badger caught a whiff of the Leipzig badger scent . Usually, a TK (presumably a voucher or discount) is worth 150 euros, and it doesn't even apply to this particular post.

Bye.
peace

Hi Pax,
The Dossenheimer car, a 3BG model, hasn't even been started yet, as it's been sitting in a garage since the move.
Therefore, it was probably the weasel from Dessau that also likes to visit the X5 belonging to the father-in-law.
It seems that the TK (presumably a type of voucher or credit) is indeed valid, so it will likely be limited to €150.
But after a move like that, you're already used to the feeling that the "gravel" seems to evaporate in the summer sun. In that case, an extra bill won't make much of a difference.
haithamina

So, did the refrigerant and the air conditioning system leak?

@ Soup of the day

According to the workshop, 2 hoses (air conditioning/heat exchanger) and 1 "pipe" related to the BKV (presumably a specific component) were affected. The material costs for each were approximately €15. However, I recall seeing on the invoice, which I briefly reviewed, something about "refrigerant topped up/checked."
I last used the air conditioner the evening before the repair. It was working normally at that time and cooling properly.

Do you mean that I misunderstood, or that it was misrepresented, and that it was actually about the fuel cooler?

haithamina

Hello,

If it were an air conditioning hose, I think you could add a zero to the 15 euros, probably making it 150 euros.

Bye.
peace

For around 15 euros, you probably won't find a single hose that's installed inside the vehicle.

Hey guys! We're in a VW forum, right?

8D0 819 371 Hose - 13.50 €
8D0 819 373 N Hose - 14.65 €
G01 2 (L?) €10.65
PDL 3 0.75 L (?) (I actually don't drink this soup!) 12.61 €!!!
4B1 611 931 AJ Print head, €32.80.
approximately 207 EUR (gross salary) + VAT, total 368.17 EUR.
haithamina

haithamina wrote:

Hey! You guys! We're in a VW forum!

Just now
Which one is the refrigerant hose now, and where is the air conditioning recharge point?

Hi!
The two hoses are supposed to connect to the heat exchanger, and I think the was talking about the air conditioning system?! Can anyone confirm this?
I mostly find coolant hoses for the engine when I search for those part numbers online.
Hmm, that leaked oil was definitely not G12 engine coolant!
The filling process is included in the labor costs.
haithamina

haithamina wrote:

... By the way, after replacing the dual temperature sensor, I also performed an actuator analysis (is that what it's called?) of the air conditioning system using VCDS, with the ignition on and the engine off, because I recently received a warning about a flap malfunction. The self-test initiated by VCDS caused the fan to start, but then not much happened, and I aborted the test after waiting for several minutes. I tried the whole process twice, but the self-test was unsuccessful: "Function currently not available." haithamina

Could the oil have been forced out somewhere as a result of this unsuccessful action, and therefore originate from the climate control system?

haithamina