Preventative maintenance - Radiator replacement?
Moderators: timk, Stu, -alex, miata, StanTheMan, greenMachine, ManiacLachy, Daffy, zombie, Andrew, The American, Lokiel
-
- Learner Driver
- Posts: 2
- Joined: Mon Jun 11, 2018 8:09 pm
- Vehicle: NA8
Preventative maintenance - Radiator replacement?
Hey guys
Would appreciate some advice.
Have a na8 with about 170,000 on the clock.
The radiator plastic looks really old and ratty (yellow/brown)
There are no signs of overheating etc.
I' m wondering whether I should replace the rad as preventative maintenance?
If so, should I also replace all hoses whilst i'm there?
with rubber/OEM hoses? or would silicon ones be better?
TIA and Happy new year!
Cheers
tim
Would appreciate some advice.
Have a na8 with about 170,000 on the clock.
The radiator plastic looks really old and ratty (yellow/brown)
There are no signs of overheating etc.
I' m wondering whether I should replace the rad as preventative maintenance?
If so, should I also replace all hoses whilst i'm there?
with rubber/OEM hoses? or would silicon ones be better?
TIA and Happy new year!
Cheers
tim
You do not have the required permissions to view the files attached to this post.
- LiteIsRite
- Fast Driver
- Posts: 424
- Joined: Mon Apr 08, 2013 8:16 pm
- Vehicle: NA6
- Location: Northern Rivers NSW
Re: Preventative maintenance - Radiator replacement?
Looks like you have a nice, clean car there Tim.
I recommend you replace that radiator sooner rather than later. I’ve been caught out with a failed top tank (on another car), it’s not much fun. I replaced mine about 18 months ago with one of these... https://www.ebay.com.au/itm/MAZDA-MX5-N ... 2049824026, although I see these are more expensive now than they were.
As for hoses, it’s hard to tell from the photo whether they need replacing or not. From what I’ve seen and read, the Mazda hoses are the longest lasting, the silicone ones not so much.
Happy New Year to you too!
I recommend you replace that radiator sooner rather than later. I’ve been caught out with a failed top tank (on another car), it’s not much fun. I replaced mine about 18 months ago with one of these... https://www.ebay.com.au/itm/MAZDA-MX5-N ... 2049824026, although I see these are more expensive now than they were.
As for hoses, it’s hard to tell from the photo whether they need replacing or not. From what I’ve seen and read, the Mazda hoses are the longest lasting, the silicone ones not so much.
Happy New Year to you too!
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6
[sold]
"Cherry" - Classic Red 1990 NA6

-
- Learner Driver
- Posts: 2
- Joined: Mon Jun 11, 2018 8:09 pm
- Vehicle: NA8
Re: Preventative maintenance - Radiator replacement?
Thanks very much for the advice @liteisrite
This does lead on to the next question....
I was wondering what I should get to replace it.
Whether there were recommendations from ebay item or similar (sorry, I couldn't follow your link) and there's a wide range of choice.
I had been thinking of this item from MX5mania : https://mx5mania.com.au/products/nb-1989-2197?_pos=17&_sid=af99d16c8&_ss=r
or this one : https://mx5mania.com.au/products/nb-1989-2109?_pos=19&_sid=af99d16c8&_ss=r as the thought of non perishable aluminium had appeal over the oem looking black plastic.
This does lead on to the next question....
I was wondering what I should get to replace it.
Whether there were recommendations from ebay item or similar (sorry, I couldn't follow your link) and there's a wide range of choice.
I had been thinking of this item from MX5mania : https://mx5mania.com.au/products/nb-1989-2197?_pos=17&_sid=af99d16c8&_ss=r
or this one : https://mx5mania.com.au/products/nb-1989-2109?_pos=19&_sid=af99d16c8&_ss=r as the thought of non perishable aluminium had appeal over the oem looking black plastic.
- 16bit
- Speed Racer
- Posts: 2346
- Joined: Wed Nov 29, 2006 1:51 pm
- Vehicle: NB8A - Supercharged
- Location: Brisbane Southside
Re: Preventative maintenance - Radiator replacement?
personally i would replace it with an alloy rad and if you can afford to buy oem hoses.
genuine items are not cheap compared to oem style or cheaper silicone hoses.
they have lasted the best part of 25 years so replacing them now should last another all going well.
it looks like a lovely unmodified car so probably best to keep it that way unless you are replacing something with an item that is more reliable.
genuine items are not cheap compared to oem style or cheaper silicone hoses.
they have lasted the best part of 25 years so replacing them now should last another all going well.
it looks like a lovely unmodified car so probably best to keep it that way unless you are replacing something with an item that is more reliable.
98 evo gold - rotrexed and loving it.
This post has been printed using recycled pixels
This post has been printed using recycled pixels
- LiteIsRite
- Fast Driver
- Posts: 424
- Joined: Mon Apr 08, 2013 8:16 pm
- Vehicle: NA6
- Location: Northern Rivers NSW
Re: Preventative maintenance - Radiator replacement?
Sorry, Tim, I don’t know what happened with that link. This one should be OK...
https://www.ebay.com.au/itm/MAZDA-MX5-NA-1-6ltr-1-8ltr-1989-1997-MANUAL-RADIATOR-KOYO-QUALITY-/322049824026
Or, for the same price, go with the Mania one if you want a thicker core. It comes with a new radiator cap as well. I’d follow 16bit’s advice re the hoses too.
https://www.ebay.com.au/itm/MAZDA-MX5-NA-1-6ltr-1-8ltr-1989-1997-MANUAL-RADIATOR-KOYO-QUALITY-/322049824026
Or, for the same price, go with the Mania one if you want a thicker core. It comes with a new radiator cap as well. I’d follow 16bit’s advice re the hoses too.
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6
[sold]
"Cherry" - Classic Red 1990 NA6

-
- Fast Driver
- Posts: 342
- Joined: Thu Feb 15, 2018 8:43 pm
- Vehicle: NA8
- Location: Sydney
Re: Preventative maintenance - Radiator replacement?
I have what I believe is the same radiator that MX5 Mania sells (not the all alloy one) and it seems fine, certainly no issues with it but fit is slightly different, there's more of a gap rather than it really being sealed against the panels. I've been meaning to source some foam tape to seal the gap. Won't make any difference but it will help ensure as much of the air goes through the rad rather than around it as possible.
As for hoses, OEM ones aren't that expensive and would be what I'd use and while you've got the rad out it makes sense to replace them unless the budget is tight. You might want to look at the heater hoses as well. They're a little more tucked away and near the exhaust so may deteriorate faster. I've never replaced them but I do know you can run into issues removing them from the heater pipes which can be damaged so need to make a judgement call if it's worth the risk if they don't really need replacing.
As for hoses, OEM ones aren't that expensive and would be what I'd use and while you've got the rad out it makes sense to replace them unless the budget is tight. You might want to look at the heater hoses as well. They're a little more tucked away and near the exhaust so may deteriorate faster. I've never replaced them but I do know you can run into issues removing them from the heater pipes which can be damaged so need to make a judgement call if it's worth the risk if they don't really need replacing.
'97 Neo Green limited edition
-
- Speed Racer
- Posts: 12011
- Joined: Mon Aug 08, 2005 11:35 pm
- Vehicle: Clubman
- Location: Melbourne
Re: Preventative maintenance - Radiator replacement?
Welcome & congrats. As apsilon says take care if you replace the heater hoses where they connect to metal pipes that emerge from the firewall into the passenger side of the engine bay as the metal is thin & pliable.
-
- Racing Driver
- Posts: 502
- Joined: Fri Mar 04, 2005 9:26 pm
- Vehicle: ND - 2 GT
- Location: Brisbane, Australia
Re: Preventative maintenance - Radiator replacement?
TimW wrote:The radiator plastic looks really old and ratty (yellow/brown)
There are no signs of overheating etc.
I' m wondering whether I should replace the rad as preventative maintenance?
When I had my NA8 I just had the top plastic radiator part replaced, was cheapest for me. And kept it all stock, if that's what you're after?
Andrew.
Previously, White 95 NA 1.8 Hard Top,Stock standard
Now, 2016 Fiat 500x, 2014 Fiat 500, 2015 ND GT 2.0
Now, 2016 Fiat 500x, 2014 Fiat 500, 2015 ND GT 2.0
-
- Fast Driver
- Posts: 144
- Joined: Sat Feb 13, 2016 5:09 pm
- Vehicle: NA8
Re: Preventative maintenance - Radiator replacement?
Regarding the heater hoses, I would certainly agree with replacing them, I had one fail some time ago, cost me a new(Second hand) head and a lot of time and money. It's not a simple job as there is not a lot of room back there, but essential for peace of mind. I replaced the radiator as well as mine was brown as well. I used one from Bursons, which is fine. However I recently got one for my ute from ebay,very impressed with it's quality and price.
-
- Racing Driver
- Posts: 1784
- Joined: Fri May 16, 2008 1:39 pm
- Vehicle: NB8A
- Location: FarSE Melbourne
Re: Preventative maintenance - Radiator replacement?
Best way to remove the old heater hoses (if replacing them) is to slice down the hose with a razor blade and peel them off the pipes. Much less chance of mangling the pipes on the firewall than the usual ‘multi grips / twisting’ option...
- MX593
- Fast Driver
- Posts: 115
- Joined: Wed May 08, 2013 3:44 pm
- Vehicle: NB8B
- Location: Canberra
Re: Preventative maintenance - Radiator replacement?
I had an experience of the silicone hoses slipping and weeping. Even with the good T-clamps. Never again, went back to good quality rubber with regular screw clamps and no more problems.
- bruce
- Speed Racer
- Posts: 7788
- Joined: Fri Apr 25, 2003 11:00 am
- Vehicle: NA8 - Turbo
- Location: Victoria
- Contact:
Re: Preventative maintenance - Radiator replacement?
I'd stick with rubber hoses as one of my silicon jobbies is impossible to tighten and it still weeps (you can smell coolant after a drive).
-
- Speed Racer
- Posts: 6444
- Joined: Mon Feb 04, 2008 11:40 am
- Vehicle: NB8B
- Location: Melbourne
Re: Preventative maintenance - Radiator replacement?
The best radiators for your MX-5 are the originals- they will fit and function for easy 15 years. You also get warranty for the part against manuf fault. A mate recently replaced with OEM and the price was ok as well. Some of these alu units are not good - what do they say about if its too cheap and its often true. Silicone hosse also not necessary as replacement for rubber.
-
- Fast Driver
- Posts: 163
- Joined: Sat Sep 21, 2013 8:52 pm
- Vehicle: NA6
- Location: SE Melb, Vic
Re: Preventative maintenance - Radiator replacement?
Definitely agree with the posts above - that brown colour means it's just waiting to fail on you at the worst possible moment. Lots of cars here running cheap ebay alloys without issues, but by the photo you have a very nice original NA there, and keeping the 'oem' look with a new black plastic one would be worth considering.
Rubber hoses are better than silicon unless you like the 'bling' of colour options. Shops like Mania do kits of original rubber hoses - fair warning that some of them are a pain to change
Also, if you can source the spring type hose clamps (like on your top radiator hose in the photo) they're better than worm-drive clamps. Easier to fit in awkward spots, can't forget to tighten them, and they maintain an even pressure without damaging the hose.
Rubber hoses are better than silicon unless you like the 'bling' of colour options. Shops like Mania do kits of original rubber hoses - fair warning that some of them are a pain to change

Also, if you can source the spring type hose clamps (like on your top radiator hose in the photo) they're better than worm-drive clamps. Easier to fit in awkward spots, can't forget to tighten them, and they maintain an even pressure without damaging the hose.
NA6 '89 red, NB8B '01 silver
-
- Fast Driver
- Posts: 342
- Joined: Thu Feb 15, 2018 8:43 pm
- Vehicle: NA8
- Location: Sydney
Re: Preventative maintenance - Radiator replacement?
Mr Morlock wrote:The best radiators for your MX-5 are the originals- they will fit and function for easy 15 years. You also get warranty for the part against manuf fault. A mate recently replaced with OEM and the price was ok as well. Some of these alu units are not good - what do they say about if its too cheap and its often true. Silicone hosse also not necessary as replacement for rubber.
Can you still get them from Mazda? If so then yeah for an NA that's stock or close to it that'd be an option worth considering IMO.
'97 Neo Green limited edition
Return to “MX5 Engines, Transmission & Final Drive”
Who is online
Users browsing this forum: Google [Bot] and 3 guests