Interior coolant leak

[Majik]

Where are the main places that can leak coolant in the interior? I can slightly smell a hint of coolant when I tun the defrost on. I was also low on coolant the other day. Anything I should look out for? I can not see any leaks in the engine bay.

[POS Racing]

About all that's in the dash with coolant is the Heater core.

Has it lost any more fluid since last weekend??

[Miatamoto]

I'm with POS, I'd say the heater core.

[trickyrix]

+1... heater core

[black roadster]

Yep. Heater core from personal experience. O'Reillys was the cheapest I found one. Lifetime warranty too.

According to BAM! it can be replaced without removing the dash but I'd think you'd need to be a contortionist.

[Darron65]

According to BAM! it can be replaced without removing the dash but I'd think you'd need to be a contortionist.

You've met him, right? I think he was born to work in tight spaces.

[2K Miata]

Sorry to say that its most likely the heater core. Its usually starts with the smell of antifreeze and then one day you've got boiling hot coolant leaking on your feet.

I have a brand new OEM one in a box I could sell you if your interested.

Most likely you'll have to take the dash out to replace it unless someone has a trick up their sleeve.

On early Miatas 90-97 you can barely get at it with some rigging (Gary's done it on his '96) but I'm almost sure you have to take the dash out on the NB's.

Thats why I have a heater core in a box. I just by-passed the heater core by joining the the heater supply and return lines together. Never got around to pulling the dash before the car got written-off.

Good luck pulling the dash is a real PITA

[Majik]

Son of a That sounds crappy. POS havent not lost coolant since Sat. Is there anything I can look for around under the dash to make sure before I pull the dash?

[POS Racing]

Son of a That sounds crappy. POS havent not lost coolant since Sat. Is there anything I can look for around under the dash to make sure before I pull the dash?

Dropping coolant levels would be one of the key things to monitor Sparky....

[black roadster]

Mine wasn't losing coolant at any measurable level but when I pulled my heater core, it had a hairline crack. The most obvious thing you notice before catostrophic failure is the smell of coolant.

Since the only coolant running into the interior is the heater core that can be the only culprit. Pulling the dash on my NA seemed worse that it actually ended up being. Good luck. If I can help, let me know.

[Treibenschnell]

I think he was born to work in tight spaces.

We'd have to ask Nexus Flux about that...

[Magma]

We'd have to ask Nexus Flux about that...

I am scared they NF does not live that far from me

[Majik]

Well I have an interior leak for sure. I really need to get in there and look to find out what the problem is. Either the heater core or the hoses conecting it. If someone on here sees or talks to 2kmiata, let him know I sent him a PM about his for sale. If not Ill call oriely for one of theirs. Wish me luck.

[Treibenschnell]

Wish me luck.

It shouldn't be too bad... good luck!

[Majik]

I think I am going to try the non dash removal method. I have read a little about it on miata.net and it seems it can be done on a NB.

[Treibenschnell]

I think I am going to try the non dash removal method. I have read a little about it on miata.net and it seems it can be done on a NB.

I can tell you that on the NA it was possible... with some cussing and cuts, but possible. Just be careful with those soft brass ends on the heater core... they'll bend rather easy.

[trackdog]

Marc,

It is not hard to remove it from your car and you do not need to take the dash out. The M2 core has removable pipes where the M1 only had one and was a turd to remove. I replaced by '96 last year with one of our used '99 cores and just a slight modification was all that was needed.

I think once you pull the seat out and crawl under the foot well on the drivers side you will see the core and understand how to pull it out. The short removal version; remove plastic cover, undue the clamp around the two pipes and pull the unit out.

Call me if you have a question.

Gary