Coolant under floor mats?

[Kain]

At Christmas, my NA6 had a water bypass hose fail (the one that exits the thermostat, goes behind the belts then into the block), so I lost most of my coolant. I replaced the hose and coolant, and twice in the week since I've had to refill the overflow container. Including those two refills, I've put about 6L of coolant in it, which is what my manual says is the capacity of the system, so I figured I wasn't losing any.

Now I've found coolant coming into my interior. The carpet under both my floor mats is damp, and when I mop it up with a paper towel I can see the liquid is green. I have no idea if it was there before the hose burst or if it's occurred afterward. Could that hose have possibly caused this? It seems ridiculous to me, but my only other thought is it's from a heater hose, and that one is even more worrying

[Steampunk]

Your heater core has sprung a leak Kyle.
I'm not entirely certain you can reach the whole heater system by removing the glove box, but you can get to most of it at least.

Since you won't need the heater for a while, you can connect the two heater hoses together for the time being.

Once again, if you need a hand, give me a yell.

[Kain]

Thanks Andrew, I was worried that was it. Will it continue to leak if I don't use the heater while driving? I'm not sure if coolant is pumped through the core all the time, or just when the heater is on.

I think there may be a trip to MX5 Plus in the near future. I'd love to do it myself, but I can't be buggered if I have to take the dash out to do it properly

[JBT]

Yes, coolant is pumped through all the time. Yes, you will have to remove the dash to get to the heater matrix.

[Steampunk]

what that JBT guy said
Do you use the heater much during winter?
The core in my Festiva leaked and I've done without a heater for the last 3 winters
Just start carrying a couple of Snuggies in the boot

[Kain]

No, I don't use the heater often at all. I was just trying to figure out if was safe to drive it and just not turn the heater on

I'll keep an eye on it, and if the leak is bad enough, I'll connect those two hoses. If it's not leaking much, I'm sure it'll be fine until Danny's boys in Geebung can take a look at it. I'm definitely going to get it fixed, it's just a matter of when.

Thanks for the help guys!

[wun911]

I hear that the heater core is part of the cooling system it's there to help cool a 'hot spot' in the engin. Originally the engin was East west orientation but now that its in the Mx5 as North south some of the coolant remains stagnent at the back of the block, so they fed the heater core there to help cool it (probably why the mx5 heat is so good and toasty in winter).

pain to fix but i would do it sooner rather than later...

[Okibi]

Andrew is spot on, connect the 2 heater hoses that attach to the firewall to bypass it until you can replace the core.

[JBT]

I hear that the heater core is part of the cooling system....

Correct.

[Kain]

Well, the leak was bad enough that I decided to bypass the heater via the hoses. It was a really painless exercise, but I couldn't get the hose to connect the inlet and outlet on the engine without kinking. Will the coolant find away around the blockage, or is it dangerous to leave it kinked for a while?

[Steampunk]

How acute of an angle is the kink? If you think that it impedes flow, then I would fix it because the coolant flow is restricted considerably.
Get a length of radiator hose from Supercheap, Repco et al.
The other two routes the coolant takes exiting the engine is the thermostat/top radiator hose, and the oil cooler/idle air bypass under the intake manifold, but this is a very small hose.

[Kain]

Bumping this back up! Now we're starting to head into the cooler months, I'd like to get my heater core fixed. Would anyone who's had their heater core replaced care to share how much it cost them?
Thanks all.

[JBT]

It cost me >$600 because I got a Mazda dealer to supply and fit the core. If you can pull the dash and get the core and get it to a radiator place you will get out of it cheaply. The core itself was fairly expensive IIRC.