Heater air flow leaks

Peterv

Active Member
#1
Hi All
Pulled my heater out today to try improve hot and cold air flows. Figured most of the air leaks are from foam seals on the flaps being shot, which they are, but what has caught me eye is the gaps in the duct to the face cold air vents.
If you inspect the photo looking into the top hole through the firewall you'll see what looks like factory made slots to behind the radio console. I'm thinking of blocking these to allow more air to get to the vents. Surely the radio doesn't get that hot it needs cooling:rolleyes:
Any comments please....
Cheers, Peter

(I haven't cleaned anything as yet, just pulled the heater box out and took the photos in case your wondering. No rust, just years of dust.)

20210826_190453.jpg 20210826_190503.jpg
 

Demetris

Well-Known Member
#2
The slots are there in order to plumb in the factory A/C system. Yes you should seal them. For the same reason there more slots taped up on the galleries that lead to the face vents. They are visible if you remove the gloveboxes and look up. Normally the tape is long gone now and you should have cooled gloveboxes.
 

Peterv

Active Member
#3
Brilliant.:thumb: Thanks Demetris. Always a logical reason for things in a P6. Have already pulled the glove box's out and the radio consul to get at the control linkages. That was the only way to disconnect them due to my large hands and small spaces. With all that cold air under the dash, it's no wonder the heater was struggling.
 

Peterv

Active Member
#4
Another question for you all.
After some to-ing and fro-ing with the garden hose I've improved the flow through the matrix after some blobby things found their way out.
However, on "heater Box Anyone" I read that good flow doesn't mean a good matrix due to an 'internal bypass' or is this just the US cars?
Can anyone shed some light on this please.
 

sdibbers

Well-Known Member
#5
I believe the matrix are the same for all markets. You can try hooking the hose to the hit tap and running it through the matrix. Feel for cold spots in the mesh as that’ll indicate a blockage.
 
Last edited:

Peterv

Active Member
#6
All back together again. Patched up the spaces on the cold air ducts. Heater matrix all great, tested with hot water. All flap seals rebuilt with 3mm neoprene foam and preloaded overnight to form a perfect seat. Any surface rust removed and complete anti-rust treatment. Fan motor dismantled and lubricated. Bottom main seal replaced with custom made seal. Repainted, installed and tested. We have heat and we have cold. (Just in time for summer) Thanks again for your help gentlemen.
 

Attachments

Top