Kühlwasserverlust nach längerer Autobahnfahrt | Posts 16+

Hello,
According to Volkswagen, this is permitted!

I would now be very cautious about how I handle that statement .

Hello,
According to Volkswagen, this is permitted!

I would now be very cautious about how I handle that statement .

Hello,
I'm not doing it, and I don't recommend it either.
I've heard from inside sources at Volkswagen that the VTG-ATL (Variable Turbine Geometry - Anti-Lag Technology) system slows down very quickly after the engine is turned off, making it harmless in that state.
The worst thing would be if the oil in the automatic transmission (ATL) starts to coke up!
Best regards,
Günther.

Hello there.

'So, I had similar problems with my A6 (engine code: AAT). In my case, it was the water pump, but unfortunately, I didn't notice it soon enough because it's so well hidden. Now, I'm dealing with engine damage because it failed and destroyed the timing belt.'

@Tractor Driver:
'On my Avenue air conditioning system, the water pump is driven by a timing belt (or V-belt). I hope I don't have this problem, as it doesn't affect the valve control.'
If any of these belts were to break, either the oil pressure warning light or the charging indicator light would immediately come on, and I would then pull over to the right side of the road and check what's wrong.

Otherwise, the question is:
In the spring, I'm going to replace the timing belt. Should I also proactively replace the water pump at the same time (I saw a new one from Ruville online for €14.99 - an amazing price!)?

Hello everyone,
To get it out of the way: The members of the ZKD were most likely right!
Sorry!

Here's a description of the symptoms that have appeared since then:
After the coolant losses initially only occurred during longer highway drives...
They gradually expanded from initial tests to daily commutes to the workplace.
In the end, I had to add a liter every day.
Water is trickling out of the outlet channel of the expansion tank.
(regarding the pressure relief valve on the lid).
Traces can be observed beneath and around the balancing tank.
Otherwise, there are no signs of cooling water anywhere.
Neither inside the car nor anywhere else in the engine compartment.
The coolant temperature is always stuck at 90°C.
I also heard a couple of times a gurgling or bubbling sound in the cylinder head area.
(Engine stopped, hood open).
When the engine is turned off, you can hear a hissing sound coming from the expansion tank.
(Pressure relief valve in the lid), and you can see traces of coolant residue on the outlet channel of the same.
During the pressing process, the system is sealed, and the pressure relief valve on the lid releases at a certain point.
1.3 and 1.5 bar.
Typically, the loss occurs at higher speeds (e.g., during highway driving).
and/or when operating under a higher load (after an increase).
During the expansion tank test (also known as the 'Blubber' test), bubbles already appear at idle speed.
At higher speeds, increasingly smaller bubbles are formed.
which then tend to become increasingly prone to overflowing.
I once noticed the following phenomenon:
I drove for 5 minutes, with the coolant level previously being correct, until I reached an incline.
With the engine running (coolant temperature below 70°C), the level had risen slightly (which is normal).
I drove the 5 km long incline (uphill section) while the engine was still running, and at that point, the level was above...
Approximately 1 cm above the maximum level, turn off the engine; the fluid level has now dropped suddenly.
It's about 1.5 cm below the minimum level. I'll park the car about 4 km further down the road.
Water level in the balancing reservoir is now almost empty.
That perfectly matches the symptoms that Thomas experienced with his timing chain issue at 212,000 km.

When tightening the cylinder head bolts, use a torque wrench (with a setting of 60 Nm).
'All the screws immediately came loose (I didn't tighten them further).'
'However, since then, the water loss has been significantly lower.'
The hissing seems to be less pronounced, but it's still there.

A timing belt replacement is definitely overdue (241,000 km; the first one was replaced at 120,000 km).
Although the timing belt still looks perfectly fine; it has been checked every 10,000 km after reaching 210,000 km.
Here's how I'm handling the ZKD change together with everything else.
I am replacing the V-belt, ribbed V-belt, tensioner pulley, timing belt, and idler pulley.
and crankshaft bolt (for 1Z engine) - not applicable for hydraulic lifters or solid lifters (oil consumption with 5W40 at 0.05-0.1 liters per 10,000 km is acceptable).

I bought a water purifier because it was so cheap at 15 euros.
However, I'm still undecided about whether to install it yet.
(It's difficult to access that area with the air conditioning unit there), and I want to complete the ZKD+ZR training within one day.
Need to get the stage set up because I need the car. I've only replaced head gaskets on motorcycles before.
Therefore, I need to factor in some extra time for unforeseen circumstances.
I'll tackle that this weekend.
Hi Broesel,

You don't necessarily have to replace the water pump, as it's not driven by the timing chain.

One day should be enough; I disassembled everything during one afternoon when I changed it and reassembled it the next day. Of course, it's much faster to do, but you don't want to miss anything.
This might be of interest to you.
/viewtopic.php?t=5693&highlight=zkd
And be sure to check the head for any damage!

and yet another one with the well-known head gasket issue...

Great that you got back to me to clarify the problem!

Regards,
arne

Okay, thanks for letting us know again.
If you're already working on the coolant system and have the water pump ready, why not tackle the thermostat as well? That way, you can get everything done at once.
Otherwise, you'll have to replace it again soon, and good coolant isn't cheap, especially since the old coolant needs to be disposed of properly if you don't reuse it.

@Günther:
That didn't seem very plausible to me (I just couldn't quite imagine it).
that without any white smoke, such a rapid and significant coolant loss through the head gasket is unlikely.
Meanwhile, I can explain it (you never stop learning).


@Arne:
It was obvious.
One should contribute to the forum.
I have also benefited enough from forum posts.
I just wanted to wait until the problem worsened in everyday use.
to be able to narrow it down more effectively.


I saw the post yesterday.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
closely examined (it includes aspects such as:
What happens to the cylinder head bolts and the head gasket during tightening and operation?
and now some things are becoming clear to me. Typically, I drive my car twice a day for 35 minutes each time.
with a speed of less than 120 km/h. So far, no longer trips for vacations.
The problem then appeared during an initial 7-8 hour long trip with the baby.
(A friend who was driving nearly the entire distance drove at speeds of 150-180 km/h.)
I believe the pre-tension hysteresis of the ZK screw/ZKD (cylinder head gasket) was a factor here.
(7-8 hours of engine hot phase ZK screw stretched preload increased hysteresis.
The initial tension has decreased over time).
I might be able to fix it by tightening the valve cover screws as mentioned above.
The forum post also describes a residual hissing sound coming from the expansion tank.
get rid of; Assuming the ZKD hasn't already eliminated any damage.
I don't think I have much to lose, and the effort involved is limited.
What do you think ?


Regarding the cooling water, I have one more question:
I previously had G11 (green-blue) in it.
I just bought three 1-liter bottles of BASF Lila (G12+), which cost 4.90 euros each. According to the forum, it's compatible.
See http://www.basf.de/basf/html/d/produkte/gebiete/glysanti/produkte/g30.htm.
It now says: Recommended for aluminum engines!

In the repair manual for my car, it says:
Engine block made of gray cast iron, cylinder head made of lightweight metal (aluminum ).
Do I have a problem there now ?

Hi Broesel,

Hey Broesel,

The purple G12+ was specifically introduced to replace the G12 (used by Volkswagen), and there were some internal inconsistencies initially, but I haven't heard anything about those issues recently. Therefore, it shouldn't pose a problem.

Regards,
arne

'Since last Saturday, when I tightened the cylinder head bolts with my makeshift method (60 Nm), I haven't had any coolant leaks anymore (only a reduced hissing sound from the expansion tank). And this is despite the fact that none of the screws seemed to turn further, and the water loss before was really significant, at 1 liter per day.'

I've decided to tighten the cylinder head bolts this weekend using Albrecht's method.
Loosen each screw individually (leaving all others tightened), tighten to the specified torque, and then rotate another 90 degrees. You do this with all head gasket screws one after another. Then, finally, tighten everything again in a cross pattern for the remaining 90 degrees. This should restore the originally specified tension. If the head gasket is still leaking at that point, you haven't invested much work.


After that, I will carefully analyze it (while possibly moving the box closer) and see if the hissing sound has also disappeared.
Until I'm certain, I will postpone the coolant reservoir replacement/coolant change, etc.

I'm really curious to see if the ZKD (likely referring to a specific component or system) was able to withstand these stresses without any damage. It would be unfortunate if the ZKD then fails after the ZR (another component or system) is replaced.

Greetings and have a nice weekend!
Crumbs.

Hello,

I have now tightened the cylinder head screws using Albrecht's method.
I was able to loosen all the screws with a similar torque.
To ensure the 90-degree angles were accurate, I needed a longer lever arm (approximately 1 meter).
- I had to exert a lot of force to get the rotation to be relatively even.
The screws did not exhibit any uneven behavior.
After driving at a brisk pace on the highway...
However, I experienced some fluid loss again.
with normal driving, there is no noticeable difference.

However, sooner or later, the final payment on the loan is due.
(She probably suffered too much.)

I will inform you after the change.

Hi Broesel,

Four notes on this:
"Expansion bolts are designed to expand by a defined amount when turned further. This is their intended function. If you loosen them, they will not retract because the expansion was non-elastic. If you tighten them again and turn them another 90 degrees, you will overstretch the bolts. There is a high risk of them tearing, and the holding force will be drastically reduced, significantly increasing the risk of a component damage (KD) failure."

"If hot exhaust gases occasionally leak through a slightly damaged ZD (presumably referring to a component), it can leave traces on the engine block and cylinder head. Therefore, even with a slightly damaged KD (likely another component), you shouldn't drive too far, as you risk damaging the cylinder head and/or the engine block."

I wouldn't drive that anymore.

4. But that's naturally your business .

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It can also be used as a verb, meaning "to gust."

Hello Guste,

Sure, here is the translation of the text from German to English:

'Regarding point 1:'
was a suggestion in the following thread https://community.dieselschrauber.org/en/viewtopic.php?t=8172&highlight=.
According to professional thief Albrecht, this was also extensively discussed and analyzed. They suggested that tightening it 2-3 times might be possible. However, it's a somewhat different case since the symptoms were still in a very early stage.

Regarding points 2, 3, and 4:
I would have continued driving if everything had been okay. However, I won't have time to change all of this until next Saturday. In the meantime, I will continue driving it – twice a day for 35 minutes each time.

Hi Broesel,

Hi,
The ZKD and ZR switchover seems to have worked so far!

It took me about 17 hours on Saturday and Sunday. It was already clear early on that it would take a long time on Saturday.
Instead of rushing things, I took the time necessary for certain tasks.
It took a relatively long time because I've only done this on my motorcycle before.
When it comes to the truly important, 'difficult,' and interesting things.
There weren't actually any problems.
Sure, here's the translation of the text from German to English:

'Only things like:'
What problems should I solve, where, using what methods and tools?
(These took the most time and effort!)
Often, the descriptions in books or catalogs are not detailed enough.
- Drain the coolant (it's difficult to access due to the air conditioning compressor).
Then, only the part of the system connected to the radiator was running until I adjusted the hose towards the thermostat.
(By tapping it gently with a wooden stick, you can access the hose that's lying on top.)
- Electrical connections (there were also 3 connections on the coolant connection fitting).
On the front side of the control unit. Does anyone know what these are for?
The retaining bracket of the central connector must be unscrewed, etc.
Common problems when you're doing something for the first time!

The rear differential cover can only be removed with the ESP wheel detached.
I didn't want to remove the ESP wheel, but there is a metal plate that runs through it.
Head stud (to which the tensioner is attached). However, the sheet metal is...
A circular recess of about 2-3 cm was made around the bolt. Then, I simply used the winch to...
Head raised by 2 cm and then swung to the side.

The alignment gauge for the NW (on the older ZR models) was not exactly centered.
(Gap of approximately 0.6 mm; with some effort, the ruler could be inserted into the gap).
I then precisely adjusted it using feeler gauges when I installed the new timing belt.

I didn't need the timing light with the adapter - the engine started right up.
The dynamic setting was adjusted correctly! (I checked the injection pressure adjustment tension.)
previously placed inside the vehicle's interior and measured by an analog meter.
Adjusted measurement range to 15V. The control range of 0V to 14V is fully utilized.
The display now appears less erratic than before (with the old timing belt, it sometimes...).
Overshoot before). In addition, the motor exhibits a phenomenon where it produces high torque at low speeds and high loads.
Make it a bit smoother/with less vibration.

I replaced the coolant with G12+ (BASF G30, Premium Aluminum Protection).
(previously, G11 was installed).
So far, there has been no noticeable water leakage, and the hissing sound from the...
The sound of the lid closing is also no longer audible. However, I've only used the motor so far.
driven at a low speed.
Tonight, I'm going to give him a harder time.

I also have the entire process documented in an Excel sheet.
(mit Tips und Tricks-, Werkzeug/Drehmoment-Spalte) zusammengefaßt. When it's finished.
I will post it here.

greetings, broesel