MX5 ARE VENTS ONLY PUMP WARM/HOT AIR - SOLUTION

mazmad · Postby **mazmad** » Mon Sep 17, 2012 8:52 am

Note sure if others have experienced the same problem.

My vents are cool only until the engine warms up and then they pump warm only. Fine on a cold day at Wakefield but it is getting pretty warm in there on track days now it is warming up.

Solution - courtesy of Miata net - here.

Hammer · Postby **Hammer** » Mon Sep 17, 2012 10:07 am

Nice find. I'll see if I can do this mod, and hopefully do improve the temp coming out of my vents with the A/C on in Summer.

Though I think my problem is not entirely this issue. It's more that Mazda Australia didn't bother re-routing the A/C unit (and plumbing) when they fitted the turbo on the SP (unlike Mazda Japan, which did for the SE).

Josh2232 · Postby **Josh2232** » Mon Sep 17, 2012 10:17 am

Thanks heaps mate I'll give it a shot! Finally I'll have cold, not jut hot or Sahara
Sent from my Lumia 800

mazmad · Postby **mazmad** » Mon Sep 17, 2012 10:26 am

Yeah bit of a worry when you are sweating and it is not even summer :shock:

Silvia · Postby **Silvia** » Mon Sep 17, 2012 12:22 pm

While I have no problem with the heater , hot air was blowing in as the seal for the bonnet was crushed down allowing engine heat into the cool air ducts under windscreen. There are ways on Miata.net to "pump up" that hollow seal by feeding in round foam strips from one end , but I found a narrow strip of sticky-back door sealing foam (Bunnings etc.)applied across the top of the rubber seal was a quick,cheap and effective fix, well worth doing.

Hammer · Postby **Hammer** » Mon Sep 17, 2012 2:30 pm

Silvia wrote:...There are ways on Miata.net to "pump up" that hollow seal by feeding in round foam strips from one end...

I did the round foam solid tube mod in my SP. I got the foam from Clark Rubber.

It did work to a certain degree, but the best mod that worked (though still not perfect) was covering the A/C plumbing inside the engine bay with insulation rubber.

mazmad · Postby **mazmad** » Mon Sep 17, 2012 2:34 pm

Good tip guys, will check that also.

mazmad · Postby **mazmad** » Sat Oct 20, 2012 6:01 pm

Update: I have tried the second method.

I have reduced the warm air spilling over from the engine bay into the cabin air intake, by inserting small stiff rubber hose into the factory rubber strip that runs across the width of the rear of the engine bay. Definitely made a difference - but I am not convinced this is the total solution.

Re the first method, control wire off the back of the hot/cold control knob:
I have tried to check the control wire / lever which runs from the cabin hot/cold control knob. Fortunately it is very easy to remove the glove box. Being able to see what the knob is doing though is more problematic. I could not see whether it even has the cable attached - jammed my head in as far as I could, with hiking headlamp, but can't quite see. It doesn't feel like there is anything attached.

Has anyone worked out a way to determine what is happening from this knob to the heater box?

With summer kicking in my motivation to fix this has dramatically increased. Supersprint next weekend at EC, if it is a hot day - I will be sweating buckets! :shock:

Russellb · Postby **Russellb** » Sat Oct 20, 2012 7:12 pm

Remember that the guide was written in the USA

Try removing the plastic panel under the steering column

mazmad · Postby **mazmad** » Sun Oct 21, 2012 11:53 am

Yeah thanks Russell, worked that out

Just hoped there might be an easier solution, from glove box side, that doesn't involve also removing the seat which the US site also recommends.

But am thinking there is probably no other option.

My problem is that it feels like the knob isn't connected to anything but it is damn nigh impossible to see in that space.

93_Clubman · Postby **93_Clubman** » Sun Oct 21, 2012 12:01 pm

mazmad wrote:Just hoped there might be an easier solution, from glove box side, that doesn't involve also removing the seat which the US site also recommends.

Removing the seat for under dash work on either side makes it a lot easier as you can lay on your back with your legs up on the parcel shelf.

mazmad · Postby **mazmad** » Sun Oct 21, 2012 12:21 pm

Not sure my legs are long enough to reach up to the parcel shelf

But yeah good call.

Will be fitting a sparco soon so that is probably the time to do it.

mazmad · Postby **mazmad** » Fri Oct 26, 2012 1:53 pm

You mean as per listed above from miata.net:

Or another solution? :shock:

kenson · Postby **kenson** » Sun Nov 04, 2012 7:38 pm

The rubber seal in the engine bay definitely helped. I had some belts from my last car which I cut up and used

But I found that I would still be getting hot air.

I checked the thermostat cable using the article mentioned (http://www.miata.net/garage/heater_cable.html) and I can see that my heater "door" wasn't closing all the way. Followed the instructions and now I can see that it closes all the way!

You don't need to remove the glovebox. Just have a look on the drivers side - don't need to remove any panels. A few plays with the thermostat and you'll see what's happening.

I also removed the glovebox, doh! But at least I can confirm my recycle/cycle knob is working... :oops:

Now, to wait for a hot day...

mazmad · Postby **mazmad** » Sat Nov 24, 2012 1:31 pm

So - with forecast of 31 deg for tomorrow :shock:

- I squirmed under the steering wheel and confirmed, yes, the spring on the door closer is attached and working, and the slider is travelling all the way in the close position. Back to the drawing board. (thanks Ken for info and details as to contortions needed to see up there).