Druck im Kühlsystem baut sich auch bei kaltem Motor nicht ab | Posts 16+

Hi there,

Thank you for your thoughts.

I'm just going to drive it and not think about it anymore. It's been like this for a while now, and the car has already far exceeded its expected lifespan. If there are any issues with the timing chain etc., I won't be repairing anything here.

I still have it in the back of my mind to replace the entire engine – who knows…
I still have an AFN engine lying around in the garage - complete with transmission.
How much effort is involved in installing an AFN instead of an AHU?
I also have a control unit.
The wiring harness should be the same.
Exhaust? The connection for the downpipe is different – I also have one from an AFN engine. I actually intended to install it in a T3 van.

Best regards,
Bernd

Quote:

The pressure will build up again as soon as heat is transferred to the coolant; it's unavoidable. The keyword here is vapor pressure. In a closed system, the same temperature-dependent pressure will always be established above and within the liquid.

Okay, with a properly functioning head gasket, it will be minimal because... the coolant has reached its operating temperature and will not expand much further, as the temperature difference (delta t) is much smaller... the engine is already warm... and therefore, the pressure difference (delta p) is also lower. When you open it, there's a brief hiss and then it stops. With a defective head gasket, it will hiss for a much longer time. Of course, the temperature must remain constant between tests.

Quote:

It will look similar with the piano burnishing process, but with less pressure and at a lower temperature. One would have to conclude that more pressure is being generated than one might expect based on the temperature. And it seems our colleague has already made this observation.

I meant that in the case of "piano," there might not be any gas transfer occurring, and consequently, the cold system could be pressureless.

@ Car service - see private message.
hg
Herbert.

As I said, practice makes perfect, and it's not much effort.
Perhaps this will be helpful to future generations...

In this sense .

I will try that this weekend. Let's see .

Best regards,
Bernd

Hi there,

So, he's still running .

Regarding the pressure test: As soon as I start the engine and it warms up, this overpressure builds up in the system. Just driving for 5 kilometers is enough – then I stop, let it cool down, and the overpressure remains.

Nothing builds up over a distance of 500 meters.

I find it remarkable that the engine, despite this damage, can still handle long stretches of highway at high speeds without any problems.
Over the weekend, I drove 1000 kilometers non-stop – from Denmark to Southern Germany – in very hot weather.

Best regards,
Bernd