"CALM DOWN AND CHILL OUT" it is "NOT" about to blow up and bring on the end of the world. Regardless of the colour and internet badly informed advice, it's an old wife's tail that spreads wrongly and fast.
This has been put together in mind of the mx5/Eunos/Roadsters/Miata's that are being used for Road use/motorways, summer fun garage queen's or driven like they have been stolen.... track time and race cars are a different subject and will need a higher maintenance scheduled than a road going roadster I would hope.
Just like the 14 degree timing that not many know why it was first being done and the reason why and how it has been changed to something else through whispers , but that is for another time... if it is going to pop, it will , trust me on that one...no matter what the colour is..
Now lets get this out there..
The Rads start off new as Black plastic, because of the heat cycle it starts to bleach, the colour starts to go Dark Green, Light'ish Green, Dark Brown, Light Brown and a off Chocolate colour White/Brown then White and cracking as the oils in the plastic have gone off to party somewhere else.
As it gets to the very Light Brown with White starting to show which starts on the outer edges first, "THAT" is an indication it is starting to dry out and get weak and has to be taken as a warning to change it.
And as the point scorers express their wealth of knowledge on the "BROWN RAD OF DOOM" you "ALL" miss the fact that the coolant hoses will have more than likely passed their useful life and I highly recommend that you change all the coolant hoses as they will be even drier and more brittle than the radiator, if not already changed.
So when people rattle on about "THE BROWN RADIATOR OF DOOM" that they have "heard somewhere" or "I read it somewhere " as fact.... ask the people that work on them for proper advice. Because some of us know our stuff where as others pretend to know their stuff.
Brand new....
NEW OE DENSO RAD...
NEW OE KOYO RAD...
NEW AFTERMARKET RAD...
It's ok....
It's ok.....
It's ok...
14 year old MK 1 NA....
It's ok.....
From a MK 2 1998....
It's ok...
1996 Mk 1 NA....
Starting to throw you a Warning... time to start to think about getting it changed showing signs of going white on the left hand side top fins, although this is still fine for the minute....
25 year old MK 1 NA...
And another....
And another.....
Swap it out now asap........
Dead.... plasitc is now chalk, living on borrowed time as most are still running old coolant hoses also, count your lucky stars it is holding coolant and not popped....
(Pic's to follow when I find them off one the many hard drives i have from working on these roadsters)
***PIC***
Just to prove that there is no preference on the "BROWN RAD OF DOOM CRAP",,,this is a new one that was fitted and just after 6 months, which was fitted by the Clubs chairmans "TRUSTED" garage to his roadster, so everyone can get done over, does not matter who you are, solution ....lift the bonnet( hood to are friends across the big pond) often and check, it cost nothing but a little bit of your time, as this one below was spraying coolant out all over and he was shy of lifting the bonnet....
And if this happens......and they are screaming the "BROWN RAD OF DOOM" crap as these have.....It is defo not...that is a over heating cooling system that has popped the rad, or the hoses etc etc "NOT THE BROWN RAD OF DOOM" they need to get deeper with the cooling system and find out why it boiled and blew "FROM OVER HEATING PRESSURE"....FACT, these happened regardless of colour, as I am sure the lads that work on them have dealt with many many times, myself included, the third one is from one of my own when a piece of shredded wagon tyre that found its way past the under tray (which I found them on strip down) on the M6 and played touchy feely with the alternator/water pump belt which I knew nothing of unitl the dampened OE gauge shot right over and she boiled and popped like old faithful in the far right lane in traffic all over the windscreen, yes my ar*e fell out....
One of mine...
So in conclusion......it all depends on the colour that is giving the warning.....NOT the years... but while others shout about the " BROWN RAD OF ARMAGEDDON" they are missing something very important....the coolant hoses and the correct anti freeze/coolant, regular coolant change , the correct coolant, not using tap water that brings on the build up of lime scale in the rads ( yes there is two) which thins out water ways and reduces the flow and brings on overheating, now I have been hit with the "tap water does not bring on lime scale build up"....sorry to disagree ,but yes it does,for a simple prime example you can see....how many have in the past had to descale their kettles at home, hard water is a killer for it, think about it for a minute....you are boiling the water in your cars far more than you kettles ..
You could always fit a high flow alloy rad, which are popular upgrades in black or polished alloy, and they will never go "BROWN RAD OF DOOM", what are the ill informed going to do about those with lack of discoloration to jump up and down about to advise on deterioration??? and IF you are still not changing coolant and adding tap water etc etc will still give you over heating issues and blown rads and hoses you will just have a polished alloy rad and a warped head...
I'll tell ya this for nowt......,ask us


Worth a read...
https://www.ebay.com/gds/Top-5-Signs-of ... 045/g.html
Drive safe, stop worrying from the doom and gloom merchants because they are everywhere and miss informed with hear say or guesses .

As always any questions please ask, it is what we are here for, honest correct info and advice..
M-m