2L CR Block EA288 | Posts 32+

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Therefore, if ice formation is possible in the low-temperature coolant and under these environmental conditions...

Hello,

The problem isn't as theoretical as one might think.

We've had three vehicles in the past few weeks that wouldn't start when it was freezing (approximately -8° to +3° Celsius). All of them exhibited significant condensation in the coolant system, and some also had condensation in the combustion chamber.

Hello, this was also reported in the M Talk forum - it's having trouble starting or not starting at all, and apparently there's water in the combustion chamber.

@bloesch
How did they diagnose the water in the combustion chamber? Did they use an endoscope? That seems quite complicated, especially in general and even more so with the EA288! How do you access it to work on it?
haithamina

PS: Basically, this must have also existed in the EA189 engine, right? Has this ever been an issue with those engines?

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Wie hat ihr das Wasser im Brennraum diagnostiziert? Endoscope?

Yes, exactly. In cases like these "failures," there is often a "reporting requirement before repair." When you report the issue, the error codes are also sent (in this case: starter motor mechanically blocked/defective). Then, the manufacturer usually or sometimes provides guidance in the right direction.

If multiple people report the same problem, eventually a Technical Problem Investigation (TPI) or, as in this case, a field action will be initiated.

I haven't had to do any DIY repairs for a few years now; but since the introduction of EU5/6 regulations, things have become a bit more complicated.

Okay.
"Starter motor mechanically blocked!" This is likely due to some water droplets flowing directly from the intercooler (LLK) into the cylinder head (ZK)...
Great system! This is really frustrating!
haithamina

Hi there.
In the M Talk forum, the first reported case of connecting rod damage on a 1.6 TDI engine was attributed to condensation. It seems there's a problem with this particular engine type that's waiting to happen...
TurboGate!
haithamina

It's sad, but interesting to know the circumstances in which that happened. I suspect it occurred during short-distance travel or city driving, because a sufficient amount of water must have accumulated first.

"

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"Starter motor mechanically blocked"! This means there are some droplets of water flowing directly from the coolant reservoir

into the intake manifold... }"

Hmm, I'm just wondering how so much condensed water can be pulled out of the low-temperature coolant during the initial startup process and with such a relatively low air velocity, to the point where it blocks the starter motor.

The intercooler is directly mounted in the intake manifold on the cylinder head. I'd like to see a real-life example of this design; so far, I only know about the SSP 514.

The LLK (likely referring to a specific component) is part of the intake manifold and is located directly on the cylinder head. I linked to information about this at the beginning of this thread, see above.
The engine is mounted with the top tilted backwards, allowing water (when stationary) to flow into the open cylinder.
@Rainer
It was supposedly a long-distance trip with temperatures fluctuating around the freezing point.

Okay, I still wonder how so much condensate can accumulate when the engine is turned off... a few drops definitely wouldn't be enough.

Well, we're all clearly much smarter than the developers of our cars, and we just don't work for them because we simply don't enjoy the currywurst in the factory canteen.

Condensation can occur whenever the dew point is exceeded. This is clear to us all. The amount of condensate produced depends on the humidity of the air and, of course, the volume of air. Now, what kind of moisture might be present in such an integrated liquid cooling system? A few tiny droplets might accumulate. Those who design these systems will certainly be aware of this. Just like with air filters and other components, there are likely to be surfaces/ridges etc. that prevent water from entering the combustion chamber.

How often does that happen? Is everything else ruled out?

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Is everything else to be ruled out?

For example, coolant from the engine cooling system?

For example, which of course wouldn't be great either. Or maybe the last puddle was too deep...or perhaps the grumpy neighbor managed to somehow get through the air filter...I could go on and on.

Okay, so...
As I said before, and without any personal interest in covering up a user error:
In this thread, bloesch reported on November 10th, 2002, that he had diagnosed water ingress into the cylinders in vehicles at his workshop.
In the M Talk forum (yes, the level of discussion is high...), several people have reported similar issues with water in the cylinders. The investigating workshop cited "condensation running into the cylinder when the engine is idling." One user with a 1.6 TDI experienced an engine failure at only 14,000 km due to a bent connecting rod. Another had to be towed because his car wouldn't start in the morning (it wasn't a battery issue), and the dealership found water in the cylinder.
There's a field measure called 23S3, and I had the software updated on it today. Previously (at 23,900 km), the tire pressure was 3-5°C above ambient temperature (even in summer on the highway). Since the update, after an initial short check on country roads and mostly in the city, it's now 5-18°C above ambient temperature.
However, the 8°C above ambient temperature (4.5°C) occurred after 1 hour of parking with a warm engine and stop-and-go city driving. This meant there was little airflow and no opportunity to shut down the low-temperature circuit of the coolant system.
I will continue to observe this and I am curious to see how it performs at higher ambient temperatures. If the software is well-designed, it should disable or minimize the heat exchanger between the engine and low-temperature coolant circuits at high ambient temperatures.
haithamina

Ideally, the Omega sump should have filled with water during the initial start-up sequence. And that water would have been drawn in from the low-level coolant reservoir?
hg
Herbert.

Hier nochmals ein re-link auf Bilder des LLK-Ansaugkrümmers, s. mein post vom 15. January 2015.
http://www.caricos.com/cars/v/vw/2015_volkswagen_passat/1920x1080/102.html
"It's surprising how much condensation can form... At 0°C, the maximum amount is around 5 grams per cubic meter, and theoretically, 2 cubic meters per minute could flow through at 2000 RPM. When the engine is turned off, surely only a few drops per cylinder can accumulate in the coolant?!"
Well, as Matthias already wrote, the designers must have considered both the component itself and the on-site measurements for raising the LLT (Lower Load Temperature).
haithamina