Hi-tech car, low-tech workshop?

Hello fellow DIY enthusiasts,

The AXR is starting to make me uneasy.

"For the past two weeks, the car has had a terrible smell... (I don't know what it smells like). When I open the coolant reservoir, it smells like burning wood. So, I took it to the workshop and had a CO test done - but there was no CO in the coolant!?" The same result was obtained at a second workshop.
"It was also great to read the comment in the workshop: "...as long as you're not consuming coolant, we can't find anything...". So, that's probably an invitation to destroy the engine so they can find something." Great!
At the same time, I only achieved 7.8 seconds in the DZR test (originally 7.5). This morning, I only managed 8.3 seconds, and the engine sounds really bad (rough and loud). But again, the workshop says: "...No CO in the coolant... as long as you're not using any coolant, we can't find anything..." Now the workshop is trying to blame the smell on my CALIX heater - they're really scraping the bottom of the barrel!

I don't use any water. The oil consumption is about half a liter for 11,000 kilometers (estimated by checking the oil level), and I don't use the car for heating (~6L/100km).
This weekend, I tried to find the source of the smell, and I discovered that the coolant hoses leading to and from the radiator smell terrible.

A frustrated DIYer gives up... So, I will probably have to have the engine removed, even though I'm against it, in order to get anything done at the workshops.
Actually, the smell of burnt wood coming from the cooling water can only lead to the conclusion that exhaust fumes have somehow entered the system.

The DZR times were achieved at temperatures around -3°C, while the original time was measured at 0°C.

Hello Bertil,

Have you had a compression test done yet? Also, what do the values of the idle speed control indicate?

Michael II wrote:

Hello Bertil, Have you had a compression test done yet, or what do the values of the idle speed control say?

A compression test was performed, and it's supposed to be okay (but I'm starting to not trust the workshop anymore ).

The idle speed control system shows no abnormalities (I was able to check this myself - thanks to VAG-COM).

Hello Bertil,

Is there a discoloration of the coolant, trending towards orange?
Is the heating system still working properly?
When you perform the permeability test, please record the most important data. Perhaps this will help a little.

Michael II wrote:

Is it possible to detect a discoloration of the coolant, tending towards orange?

... no, green and darker...

Quote:

Is the heating system still working properly?

... she's always been bad... It's only now that it's starting to smell!

Quote:

When you perform the permeability test, please record the most important data. Maybe this will help a little bit.

I can only do that next week, as I've lent out my laptop. What values do you want?

Hello Bertil,

Green? The G12 coolant specified for TL VW 774 F (required for AXR engines) is purple and can only be mixed with the reddish G12 coolant. Green coolant is actually only G11 and doesn't belong in your engine.

While it's almost off-topic, I always thought that the VAG standards G xx were more intended to keep third-party manufacturers of antifreeze, like BASF, out of the market. If VAG's own products aren't always compatible, what about products from other manufacturers?

Hello Christian,

Unfortunately, it's not that simple. G11 can cause damage in systems that are only approved for G12 and later versions. Particle formation is just a smaller part of that.

Michael II wrote:

Green?? The G12 coolant, according to TL VW 774 F (required for AXR engines), is purple and can only be mixed with the reddish G12. Green was actually only G11 and has nothing to do with your engine.

Hi Michael,

Sorry, I meant red-orange (I'm not colorblind!). I was just thinking about something else, and I accidentally typed "green" instead. "G12" is also printed on the container.

Hello Bertil,

Is there a brownish deposit on the walls of the balancing tank? What does the lid look like? Is it clean, or does it have any dirt or stains?

Michael II wrote:

...can you see a brownish deposit on the walls of the balance tank?

No.

Quote:

... What does the lid look like? Is it clean, or does it also have any dirt or stains?

Everything is clean . The coolant is very clear, and there are no visible particles or contaminants.

That's the annoying part! Everything about the car suggests complete normalcy, except for the awful smell.

Can the Calix heater really produce such results? Do you think that's possible?

Hi Bertil,

Could the problem also be with the heat exchanger in the heating system?
If something 'burns' or dissolves, it can sometimes produce a smell like that.

(But it's true that your observation about the engine sound and performance is quite peculiar.)

Surely, the problem can't be with the auxiliary heater?
I sometimes 'sous vide' food for over 2 hours without any noticeable odor.
And what could possibly produce a smell there?

Markus H. wrote:

... Could the problem also be with the heat exchanger in the heating system? If something "burns" or dissolves, it can sometimes produce a smell like that.

It smells bad even without the heating on (it's freezing!), and the smell is coming from the engine compartment.

Quote:

... Surely, the problem can't be with the auxiliary heater? I sometimes "sous vide" food for over 2 hours without any noticeable odor. And what could possibly create a smell there?

I'm wondering that too...

Hi Bertil,

A smelly heater is usually caused by a water leak, in my opinion.

I always describe the smell of hot coolant as Maggi (= a seasoning broth).
Of course, it will also smell like that with the expansion tank open (engine warm).

I'm just wondering if someone might also perceive this smell as burnt wood .
If it's clearly something different than my Maggi - have you ever considered braised beef and looked for recipes accordingly?

Or perhaps there are any dragging parts in the area of the brakes/transmission --> How does the car roll when in gear with the clutch depressed?

ulf wrote:

I'm just wondering if anyone else might perceive this smell as burnt wood

Hi everyone,

I would say that the smell could be described as burnt wood . It's quite pungent.

@Bertil

My sincere condolences for the competence of your workshops, but the decline in sales at VW will definitely make things very difficult for them in the future!

6 liters of fuel consumption for your PD . I got over 1400 km (4.7 liters) with my 1Z on the last tank !!!! And that was with a station wagon in winter, with cheap winter tires and a roof rack . No, no... the speedometer is working perfectly!!! This annoys Schröder and makes my wallet happy .

Best regards, Christian.

ulf wrote:

... A smelly heater is usually caused by a water leak, in my opinion.

I think so too.

Quote:

I always describe the smell of hot coolant as Maggi (= a seasoning broth). Of course, it will also smell like that with the expansion tank open (engine warm).

Coolant usually has a very sweet taste.

Quote:

I'm just wondering if someone might also perceive this smell as burnt wood .

So, charcoal has a rather pungent smell. The cooling water should have a sickly sweet smell.

Quote:

If it's clearly something different than my Maggi - have you ever considered braised beef and looked for recipes accordingly?

Okay, nothing found. No leaks either. "If I smell directly at the upper radiator hose (on the outside), it smells just as bad as the car currently does."
Is it possible for coolant hoses to emit such extreme fumes?
The car only smells bad when it's warm. During test drives last night, I didn't smell any odor coming from the heater anymore.

Quote:

Or perhaps due to any sliding parts in the area of the brakes / transmission --> How does the vehicle behave when rolling with a gear engaged and the clutch depressed?

Everything is perfectly normal.
This morning, it ran perfectly again (although it was -12°C)!
I'm at a loss. Okay, I'll just let it sit and hope that nothing else happens.

Thank you for your help.


@haehnlein
For fuel consumption, you should know that I don't drive on highways (BAB), but only very winding country and rural roads with some elevation changes. My 1Z also only needed 0.1 liters less.
On the highway to Essen and back, I used 4.5 liters per 100 kilometers (with plenty of time and driving at a relaxed pace).