Airbox thermostat failure...

[Francisco86]

I'm currently also working on the hot air flap, started because the vacuum hose connector broke but when I remove it, it looks like this:
ansaugluftvorwärmung.jpeg
ansaugluftvorwärmung2.jpeg
If I understand it correctly the piston in this part should press the hot air closed and the vacuum can pull the hot air flap open.
So this is not fully closed and therefore the thermostat that runs that piston that closes the hot air flap should be replaced, right? (I looked up the part number 9142616, it's available for 17€). However I have no idea how to get it out.

Now I bought a really cheap used airbox, which seems to have the same problem but I can tinker around with this one and if I break it it's not so much of a problem. Also I could fix the hot air closed on this one and repair the other one until it's winter time.
ansaugluftvorwärmungaussen.jpeg
I've also looked on the one of a V70 which has clips on the outside, this one seems to be sealed so I can't access the part which should be replaced from there.

Also, the hose that goes from the thermostat to the air box, is it plugged on the bottom or the top (2 hoses on the air box)?

[abscate]

The order there does not matter. The thermo valve on the air box controls vacuum passing through the two Hoses from manifold to the damper motor, so which hose is where does not matter

[Francisco86]

The order there does not matter. The thermo valve on the air box controls vacuum passing through the two Hoses from manifold to the damper motor, so which hose is where does not matter

Thanks for the info. I replaced the brittle stock hoses by standard black rubber fuel hoses, is that an ok option? Should technically do the same thing.

I've had another look at the thermostat housing and it is sealed as the hose coming out of it creates a vacuum thus effecting the position of the air flap.
So either I try to cut it out and then reseal it or maybe there is a way of changing this damn thing without butchering the whole housing.

[wizechatmgr]

The order there does not matter. The thermo valve on the air box controls vacuum passing through the two Hoses from manifold to the damper motor, so which hose is where does not matter

Thanks for the info. I replaced the brittle stock hoses by standard black rubber fuel hoses, is that an ok option? Should technically do the same thing.

I've had another look at the thermostat housing and it is sealed as the hose coming out of it creates a vacuum thus effecting the position of the air flap.
So either I try to cut it out and then reseal it or maybe there is a way of changing this damn thing without butchering the whole housing.

I think I'd just look into junkyard stock. Odds are there are many others that work correctly and can be found for cheap.

[blackVolo]

My -94 940 b230FD made a weird noise:



So i took the cold air tube off. The noise came from the flap not closing fully:

https://youtube.com/shorts/wLP65oJIVx0

So i just drilled a hole into the flap and the Y housing, put a nyloc screw and bolt throught the hole to keep the flap on cold always:

[wattvolvo]

Thanks to all for this thread. Modified it to cold air only on daughters daily driver 850 GLT non-turbo. Drilled pilot hole in case and threaded screw in to hold hot flap closed. Note: just read mileage from ECU and its at 300,250. Goal was to reach 300K. Everything is gravy from here on!