dvs_dave

When testing with a hose, did you put a loop between the two heater matrix supply and return lines? The valves control both the supply AND return flow for each heater matrix, not just the supply. If you did that then water should have come back out of the main return line to the engine when you manually activated the valves.

And to reiterate, the valves are operated my a pulse width modulated signal, not plain 0-12 volts. So you need to bear that in mind when testing things with a voltmeter.

kristiann

I only put the waterline to the supply and then pushed the valves to see the difference

dvs_dave

Have a look at the diagrams from the SSP I posted previously. The valves simultaneously control both the supply and return. Putting a loop connecting the two ports to simulate each heater matrix will verify that the whole valve is flowing on both sides. Also, do the solenoids not “pull” on the valve plunger rather than push them? Not sure how they would work to push them? When there is no voltage, the default position for the valves should be 100% open. Still sounds like that’s not the case with yours as you’re having to manually move the valves to make them open?

kristiann

Yes, I can manually push them down. When I give them 12v current - they mobe a bit but not fully down. I dont know if the black protection cover gives some more “pushing power” to the magnetic inside or not. Never the less - when i push the valves down physically - there is still no coolant movement. NO hot coolant gets to the valves no matter what I have done

dvs_dave

It’s a pulse width modulation signal that gets sent to the valves. So putting plain 12v to them will not do much. What happens when you pull instead of push the solenoid valves? In my experience electrical coil pulls the solenoid, not push, and they have a spring return.

kristiann

There is nothing to pull. They are all 100% “pulled” up. At least the 3 units I have taken apart. They can only go down, as “pushed” down



Pic from Phaeton

dvs_dave

The confusing part is when they have zero voltage applied to them/they’re on the bench, why aren’t they 100% open? In the SSP it specifically says that they should be, but in your case you’re needing to manually activate them by pushing them down? Makes me think maybe you’re over extending them and pushing them to the point where the supply port becomes the return port? As you can see, the supply and return ports are activated simultaneously, so you need to test that the supply and return ports on yours are also opening simultaneously.

Another thing to try, swap the coils from one of the spares you have onto the valve block you have in car. See if that helps anything.

kristiann

Already changed the coils yesterday. No difference

dvs_dave

Do you have any hvac fault codes? Have you done any diagnostics with VCDS? Running out of ideas, and the electronic side of things is still a missing part of this picture.

kristiann

I have no vcdc. Made some diagnoses and resets with Launch that we use on forein cars. Had some 28 faults. Zerod out and 23 came back.
Car seems to have some serious el problems. It seems to forget the seat and steering wheel settings, interior lightning settings. Sometimes pulls out eps faulta, lights misfaults etc.

Today radiator hose came out broken. Squeezes broken with a wrong clamp. Also explained the heater problem to the lpg installers and they said they will look into it. They have some experience with these cooling systems and one guy just spent 45mins on a A6 getting all bubbles out. And since the already installed earlier lpg system is a weird install, they were willing to check that out to make it better if possible

we shall see what they find, asked them to take the smaller hoses off aswell while they are messing around in that area to check for any possible problems