I suppose it’s not unexpected, but after 20 years and 78,000 miles the heater core in my DB-9 has sprung a small leak. At least now I know where that pint of coolant has been going every 1500 miles or so. The factory manual calls the core the “heater matrix” and it seems to be located in a single, large plastic box located in the passenger compartment, at the firewall, below the waterfall and behind the nav display. The same box also houses the interior A/C plumbing, including the evaporator. The manual calls the box “the A/C Unit.” Questions:

1. Has anyone experienced the joy of pulling the A/C unit out of the dash? Any videos, photo blogs or other instructions/guides/advice out there? Early V8 Vantage is likely similar if not identical, so Vantage owners are welcome to chime in.

2 . Has an anyone paid to have the heater matrix or A/C evaporator replaced? Would love to know what it cost and the number of hours it takes.

3. Are there any known parts substitutions for the unit, the matrix, or the evaporator? Such as parts from Volvo, Jaguar, Mazda and other Ford companion brands from that era?



Thanks in advance for your responses.

 

If I recall, the HVAC box itself is Mazda. The heater core and evaporator have custom formed aluminum lines permanently attached to it so they're probably bespoke for the VH cars. The heater core part# is 4G4318D671AA and evaporator is 4G4319F616AA each are less than $200 at Scuderia.

On the topic of replacing the heater matrix the service manual starts out with, "Remove the instrument panel." Ouch. That does not sound like a fun job.

 

Ya, when I eventually was able to locate those parts at Scuderia I was pleasantly shocked at how low the price was. RX-8 prices, not DB9 prices. For some reason the RHD equivalents are 400% more. Regardless, l’ll take the savings.
The factory manual oftentimes goes massively overboard with what has to removed to access a part. That’s why I’m hoping somebody with actual experience might chime in. Maybe I’ll go over to PistonHeads and ask the Brits.

 

I would be adding a tube of alumaseal stop leak. The stuff works and has never caused me a problem. Lasts indefinitely.

 

it took me awhile to respond because my big toe got caught in my ear while I was kicking myself in the head.
LOL, a solution from the time of flathead V8’s and rotary phones that I’d totally forgotten about. I learned on my daddy’s knee that the downside is it can plug up a good part of the radiator, but that was back in the day of brass radiators that started corroding on day one, and the aluminum radiator in my DB9 is only 3 years old. I’ll give it a shot and, hopefully, avoid having to choose between a $4000 repair bill or 30 hours of my own time dissembling the dash.

 

Remember, it’s going to take a few drives for the stuff to find the leak and plug it so be patient. I’d start with 1 tube of alumaseal and see what happens. I have never had an increase in observed operating temp