My aircon has being playing up recently. When I first turn on the aircon it gives off a really bad smell which lasts for about 10secs (smells like cat piss). After that, the aircon works fine but i think the cold air masks the bad smell. So when I get out of the car for a while and go back into it, the car smells quite bad. At times I have even had brown foam blow through the vents whilst the a.c is on. Just wondering if anyone has had the same problem?

Smell of fungal growth on leaf litter, bit of BO dissolved in stagnant water. Smells nice, yes?
Check the drain tube is clear.
Run tbe heater on full blast to dry things out. Run engine, wind down all windows, turn heater on, fan full blast.
Don't be in the car at the same time.
When I think of it, I turn the AC off but leave the fan running 1 km before I come to a stop to dry things out and not get that smell.
It's a health hazzard as well. Legionaire's disease.
More modern cars have filters to stop air borne stuff from reaching the wet AC bits.

Sure it's not the dreaded coolant getting into the vents due to leaking heater core?
This is a common problem with ageing magnas and can be accompanied by what looks like a barely noticeable vapour or steam coming through the vents.

The other way to check for this is to lift the carpet on the passenger side front footwell & see if there is any coolant leaking into it (or forming a puddle there).

From What you are describing, I'm thinking that could possibly be the issue (Keep an eye on the engine temperature gauge also, as if there is a leak, the engine's temp will eventually go up)
Let us know.

Yep checked the mat on the passengers side and there is coolant leaking. And the temp is up on the guage. Sometimes 3/4 high. Cheers for the fast response guys. Now time to fork out a bit of money 😯

Not such a simple fix then. Make sure you disinfect everything in the fixing process or the mouldy smell will linger for months.

Yikes!! Sorry to hear that it was the heater core. :-/
That is a prick of a job to do. Let us know if you want to have a shot at DIY to save money as I can find the article that site owner Mal wrote up a few years ago and post it here.

@Yellow_03

I believe it is generally quite warm in Western Australia which your avatar says that you are from.

Instead of doing the full job and paying someone else, you might consider just bypassing the interior heater core altogether.

You need to "loop" the coolant hose inside the engine bay so that it does not enter or exit the firewall.

It will end up saving you big bucks, but you will lose your heater.

That's a small penalty to pay if you live in a warm climate, and what I will be doing if my heater core ever starts leaking.

Please ask more questions if you need help with this.

Here is a thread with some images to give you a bit of a guide:

http://www.aussiemagna.com/forums/showthread.php?t=106449&highlight=heater

Yep checked the mat on the passengers side and there is coolant leaking. And the temp is up on the guage. Sometimes 3/4 high. Cheers for the fast response guys. Now time to fork out a bit of money 😯

Ouch, I had mine start to leak a few months ago - kinda ruins your day huh?

First off as I'm sure you're aware, dont drive it unless the heater is bypassed or the core is fixed, the heater core is 'always on' meaning there is no valves that open for when the heater is in use. Instead coolant is constantly flowing through it regardless of if the heater is on or not.

The bypass is the temporary fix, disassemble the air intake system (snorkel, airbox, unplug the MAF, then pull off the piping connected to the throttle body). Then disconnect the clamps for the two hoses that run from the engine through the firewall. (Some coolant will probably spill out, but in your case if you've already lost a fair bit it might be dry). Then twist one of the hoses coming from one of the engine pipes back onto the other, creating a closed loop. Re-clamp these down to ensure a secure fit. Then reassemble the air intake and top up with coolant as necessary.
I'd also put a thick rag or other absorbent material in the space between the bottom of the heater box and your ECU box to soak up/catch any residue around the ECU (best way is to access this through the drivers side footwell.

That will keep you going while the weather is warm, but on the colder nights the lack of heater is very noticeable!

The actual replacement of the core is not difficult, but does require a degree of attention to detail/OCD.
Use Mal's writeup as a guide, it is super helpful and saves a lot of time trying to work out what comes next.
Here's the link: http://www.aussiemagna.com/forums/showthread.php?t=66385&p=1020809&viewfull=1#post1020809
Make sure you take lots of pictures as you go, they are a huge help when it comes to reassembly time.
Although it is possible to do by yourself, I would definitely recommend having a second set of hands for the removal and installation of the dash piece - its big and awkward and you don't want to break things.

For the replacement parts, buy the core itself, the seals and the elbow pieces. Don't skimp out here as this is not a job you want to do twice. The core should come with the spacing foam already, but if it doesnt get some from your local bunnings. If you dont put in the foam it can cause a very annoying rattling from what I've been told.

I had a friend of mine to give me a hand for when I did mine, and took us about 7 hours to do thanks to having Mals guide (I'm sure it would have been more like 10 hours if we didn't have that)
Luckily I managed to smell the leak pretty early in the piece so it hadn't soaked into the carpets, so we didn't have to go through cleaning the carpets.
Also once we had it all back together and turned on accessory/engine start, everything was working so we didn't have to go back and troubleshoot things - so again take heaps of photos, take your time and do it once, do it right.

So you take you're careful and take your time it's a pretty straightforward job. Good luck :)

Heater Box out:
http://i.imgur.com/FKr0e3w.jpg


All back together again:
http://i.imgur.com/VT3T8Ea.jpg