Miata Plastic Radiators: The Brown Death

[MX595]

I have a quick question, can someone explain the signs of "brown death" of the radiator? I haven't been able to get a direct answer...also it sounds like the radiator is a bit rattly, I just replaced my timing bet, pulleys, water pump, etc.

[— kung fu jesus —]

The "brown death" is common to all radiators with plastic tanks. As they age and heat cycle, the color of the plastic end tanks changes from black to a green-brown color, indicating they are becoming brittle and susceptible to cracking and breaking, often with no notice.

If it is rattling, either it wasn't installed correctly, is missing a lower mount, the upper mount is missing a bushing, upper mount is loose, or a combination of those. It could also be the cooling fan(s) are missing a mounting bolt or had one snap off and is rattling against the radiator.

If you have the means, replace the radiator with a metal unit. Aluminum, brass, whatever. Far more durable.

[MX595]

Mishomoto is an acceptable replacement right? may go for the larger version

[Rogue]

I still am replacing OEM radiators after 20 years, so I wouldn't consider them less durable.
I run a replacement OEM style radiator in my wifes street Miata with no concern.
They cost less than $100.

[— kung fu jesus —]

Mishomoto is an acceptable replacement right? may go for the larger version

Yes. Be aware the larger ones (the 52mm ones) can have interference issues with larger aftermarket front swaybars. I have read of *some* fitment issues with the Mishimoto and Godspeed units, but that was when they first rolled out, not sure about now. I have a Mishimoto aluminum radiator in my e30, no issues, but not apples to apples.

[— kung fu jesus —]

I still am replacing OEM radiators after 20 years, so I wouldn't consider them less durable.
I run a replacement OEM style radiator in my wifes street Miata with no concern.
They cost less than $100.

tough to buy peace of mind, but I understand that.

[MX595]

Thanks for the input, i'll probably go oem for peace of mind

[— kung fu jesus —]

Good choice. Better now than when something bad happens!

[—atank—]

This one is ready to go anytime............................

[MX595]

Yea, looks like the doo doo brown is all over the radiator, so that will def be replaced as well as hoses

[Blueiii]

I'm still always surprised when people bash on the plastic radiators... Most of these are over 2 decades old by now. Mine is still the original, and brown.... (Hoses and new radiator just waiting to be installed.)

If you think you might ever autocross the car, most classes require the original factory (style) radiator; aluminum radiator will technically bump you into a different class, although few people would ever enter a protest on that. (And if they do, save your radiator fluid from the swap and spritz it liberally onto their cold motor at the next event, then wait for them to freak out.)

[—atank—]

Mine is from a 1999 model so its done well and still going..............

[— kung fu jesus —]

I'm still always surprised when people bash on the plastic radiators... Most of these are over 2 decades old by now. Mine is still the original, and brown.... (Hoses and new radiator just waiting to be installed.)

If you think you might ever autocross the car, most classes require the original factory (style) radiator; aluminum radiator will technically bump you into a different class, although few people would ever enter a protest on that. (And if they do, save your radiator fluid from the swap and spritz it liberally onto their cold motor at the next event, then wait for them to freak out.)

Because I have seen them fail when they change colors like this. Cool that you want to autocross on as small a budget as you can, but which is going to make more sense? Spending $100 in preventative maintenance versus $350+ on a busted motor? Making important repairs or critical systems upgrades while worrying about autocross classing on a daily driver tells me your ego and desire for a little plastic trophy means more than your transportation, maybe I'm wrong?

[Mostro]

*shit happens*

[—atank—]

*shit happens*

Yes, this is what I am waiting on with my 99...............just a matter of time.........