VP-VQ Climate Control-Cabin Air Filter

[MikeC]

My VQ's air handler is in bits for an evaporator replacement- due mainly to it being covered with dirt and composting leaves.

I don't want this to happen again and I'm looking to installing some kind of cabin air filter to keep the evap clean. One location for a filter that will clean both fresh and cabin air going to the evap would be on the fan inlet, under the diverter shroud.

The other location I could find is in the windscreen plenum , where the unit gets its fresh air from. This location won't filter return air from the cabin, but it's the only filter location used in many cars , including later Commodores.

Has anyone installed a cabin filter in either of these locations? Anyone have any comments on these proposals?

 

[Fu Manchu]

There is a member who is planning to 3D print a clip in carrier for a filter. They have done VK and VL I think it was.
They just need a VN-VP (which also includes the VQ) to work with.

Getting one under the recirc door would be the best for changing the filter though.

 

[Fu Manchu]

I take my hat off to you for getting the bloody HVAC out. It’s a horrible job.

I did it on my VP. Hated it.

 

[MikeC]

I take my hat off to you for getting the bloody HVAC out. It’s a horrible job.

I did it on my VP. Hated it.

Still got to get it all back in and working.

 

[Parso231]

Hi all,
Agree this is a big job,
I have my VP Berlina dash out currently to replace the heater core.

I’ve read the other threads on the evaporator being impossible to find what are you using for your VQ?

The flange that joins the pipes through the firewall to the evap on my Berlina is covered in dirt and crap, looks like it may have been leaking there.. I’m tempted to clean it up and install new o-rings but don’t want to have to pull the dash out again if somethings no good!

 

[MikeC]

There are 2 O rings under that flange. If they're leaking a freon detector or green refrigerant dye will pick up the leaks. I replaced them once but that didn't fix the leaks. My evaporator core corroded along one side under a pile of composting leaves. The leaves etc get wet whenever the evaporator ices up- which is after about 40 minutes driving due to the impeded air flow.
I couldn't find a VQ evaporator anywhere. Had to cut the manifold flange off the old VQ evaporator ,buy a VS evaporator and install new header pipes on it together with the old VQ flange. Have a look here:

https://forums.justcommodores.com.au/threads/modifying-vr-vs-evaporator-to-use-in-vp-vq.298991/

I'm installing a new heater core as well as a new evaporator while the dash is out. I never want to do this job again. That's why I'm also fitting a cabin filter of some sort.

 

[Parso231]

After having a look through your other thread, I decided to pull the Evap out and inspect.. happy I did!
It was choked up with gunk and leaves like yours. I gave it a thorough clean with water and compressed air blowing backwards from the bottom through all the fins. I can now see through it and gave it a pressure test at 30psi in a tub of water and it didn’t leak which gives me some confidence..

I am going to re install the cleaned Evap and hope with some new o-rings it won’t leak. I really don’t want to have this apart again and haven’t got access to a shop capable of retrofitting one like you have!

Cheers for the help so far!

 

[MikeC]

My car spent a lot of its life parked outside, often under trees , which hasn't helped, but to really make sure it won't happen again you need to install some sort of filter or screen in the air path to the evaporator- I'm looking at either the windscreen plenum intake or the fan inlet under the "eyelid" fresh air /recirc selector damper.

 

[Parso231]

Couldn’t agree more this needs a filter! Have you any ideas what type of filter for yours yet?
I have the whole unit back together and in my car now, will finish the a/c lines in the plenum when new o-rings arrive ..
I will fit a filter inside the plenum too, just working out the best way to go about it.

My Gregory’s manual was pretty brief on the instructions, there were a lot more things to disconnect / remove in my car than it had described, but thankfully I took a fair few photos. Anyone else attempting this should do the same! Big job

 

[MikeC]

My current idea is to make a plastic frame holding a screen of #100 SS mesh then mount it on the plenum fresh air intake shown on the RH side photo above. The frame would be wedged under the window-where the plenum makes a sharp angle against the window frame and would be held in front by self tappers- where I can get a screwdriver at them. Anything that can get through #100 mesh will blow straight through the evaporator coil. Alternatively you might find a cabin filter that can be cut & adjusted to fit this opening but I like the idea of just removing the screen and blowing it clean with CA.

If you've had the refrigeration system open for a while make sure you vac it out before recharging or you can get water in it and freezing of the orifice tube.