Rusty, dirty water in radiator.

I have a 96 that's been sitting up for a bit. When I say a bit, it hasn't been on the road in about 3 years. It's been garage kept and gets started and driven around the block from time to time. A week or so ago(prior to getting a new radiator cap), the cap blew off while I had it running and all kinds of black crap blew out of the radiator. I have a "air to water" intercooler and the water in the reserve is all murky too. I have noticed some rusty looking water as well.

My question is this: Should I pull the radiator and see what kind of mess I'm dealing with or start with a radiator/system flush? I'm wondering if the whole system is totally gunked up. The car will run and idle fine and doesn't run hot(yet) but I know this is something that needs attention. I want to change the radiator anyway so I don't want to double work.

She's not a daily driver but just tired of seeing her sitting in the garage! :burnrubr:

If the goop and rust is in the radiator it is in the rest of the cooling system.... :-(

http://www.miata.net/garage/CoolingS...s/image002.png

Is the radiator is leaking or old? Flush the system out with distilled water a few times. How's the color of the radiator itself? The darker, the better (if it's OEM plastic).

Yeah, I'm afraid it's in the whole system...

The radiator is not leaking or anything...it's OEM for sure and pretty dark. When you say flush the system with distilled water, do you mean drain the radiator, fill the system, run it..drain and repeat?

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Originally Posted by titanescape

When you say flush the system with distilled water, do you mean drain the radiator, fill the system, run it..drain and repeat?

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Yes...You should also throw in a flush product with the water the first time thru.

Ok, cool. I'm also guessing put her up on jack stands so I can get a bucket under the radiator drain. Any recommended flushing product?

Unless your car is slammed, you shouldn't need to put it up in the air....I think I used a Prestone product.

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Originally Posted by titanescape

The radiator is not leaking or anything...it's OEM for sure and pretty dark.

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Any idea on how old it is? I don't care what anyone says Miata plastic radiators are not lifetime parts. ;-)

Heck any plastic Radiator is not a lifetime part!

I had old, rusty, antifreeze in mine. I did my initial flushes with normal water, yes flushes, to get the system as clean as possible then added fresh distilled water/antifreeze. Drove it for about 1000 miles and then did it again.

Miata cooling system is the miata's Achilles heel. It needs to be done right. Given the age of our first gen miata, consider installing new rad, the 9 hoses, new thermostat, and new coolant. All can be done DIY for about $200.

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Originally Posted by POS Racing

Any idea on how old it is? I don't care what anyone says Miata plastic radiators are not lifetime parts. ;-)

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If it's dark, it's not old. ::2Cents::

I will take a pic of the radiator and post so ya'll can see. I haven't changed it since I had the car and I bought it a like 6-7 yrs ago. It has around 123k on it. I do plan on changing all the hoses but that's down the list a bit. I just want get it all flushed out and good while I work on some other stuff.

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Originally Posted by sammm

If it's dark, it's not old. ::2Cents::

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I had one pop the top and it had recently been deemed "oh yea that one looks good". ::hal::

Plus I believe titanescape's Miata may have extra heat making bits and pieces under the hood. ;-)

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Originally Posted by titanescape's sig line

Nothing like the whine of a SC at full throttle!

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Originally Posted by POS Racing

I had one pop the top and it had recently been deemed "oh yea that one looks good". ::hal::

Plus I believe titanescape's Miata may have extra heat making bits and pieces under the hood. ;-)

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You are correct! I'm running a MP45 with a Air to water Intercooler. I plan on upgrading to the TDR air to air. I'm not fond of this one.

Sorry about the double post. I was trying to add a quote and somehow I posted twice!

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Originally Posted by titanescape

You are correct! I'm running a MP45 with a Air to water Intercooler. I plan on upgrading to the TDR air to air. I'm not fond of this one.

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As the old saying goes! Radiators are cheap, Motors are expensive. ;-)

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Originally Posted by POS Racing

As the old saying goes! Radiators are cheap, Motors are expensive. ;-)

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No argument out of me on that. Looks like I'm in the market for a new radiator! Better safe than sorry.

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Originally Posted by titanescape

No argument out of me on that. Looks like I'm in the market for a new radiator! Better safe than sorry.

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I don't mean to sound like a radiator pusher... ::pimp::

But if you don't know the age and ya have some rust issues it may be time to clean out the system (using the old Rad) and then put in new Rad. Especially since Boost = Heat.

You must work for a radiator company!! Just kidding :)

I really have no idea how old it is. I originally bought the car from Tom(RIP) at Miata Technologies so there's no telling. I'm guessing it has been replaced once because it doesn't look like there's a 123k miles on it. I'm going to do pretty much a complete refurb on the car(just project work with the kid) so might as well replace it. The interior is in great shape just want to get all the mechanical up to par. I will take your suggestion though to flush out the system and then put in the new rad as well as hoses.

Didn't know about the boost. Get the new radiator...it's cheap insurance.

PS - Do OEM's have enough cooling capacity for a boosted engine? I have no clue, just wondering.

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Originally Posted by sammm

PS - Do OEM's have enough cooling capacity for a boosted engine? I have no clue, just wondering.

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^ That is a good question!

Decent basic overview of a "Super Flush"

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Originally Posted by sammm

PS - Do OEM's have enough cooling capacity for a boosted engine? I have no clue, just wondering.

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The OEM radiator (and entire cooling system) seems to handle normally aspirated quite well. As long as my cooling system is 100% functional, then it keeps my engine cool in some very harsh track/autocross environments.

However, I am pretty sure you would need to step up if you are using FI.

I don't track mine and I didn't have any heat issues before when I was driving it daily. I could run the AC on a 100+degree days in traffic and be fine. The only time the temp would go up was if I was tailgating and the flow of air was gone from my front end. That was before it sat up for a while and all this gunk appeared. A new radiator was on the list of upgrades just because I figured it needed on any way.

Thanks for the Super Flush link, very cool!

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Originally Posted by titanescape

You must work for a radiator company!! Just kidding :)

I really have no idea how old it is. I originally bought the car from Tom(RIP) at Miata Technologies so there's no telling. I'm guessing it has been replaced once because it doesn't look like there's a 123k miles on it. I'm going to do pretty much a complete refurb on the car(just project work with the kid) so might as well replace it. The interior is in great shape just want to get all the mechanical up to par. I will take your suggestion though to flush out the system and then put in the new rad as well as hoses.

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You can't tell by looking if the rad is going to fail. As they age, the black plastc top turns color to olive-drab green and then it fails. The time between color change to failure is unknown so most recommend replacement when you notice the color change. Why? Because all the ones that failed were olive-drab green.

But they also last for years after the color change so color is not a good indicator of failure. My personnal rule of thumb for the NA is replace at 20yrs or 100k miles.

Bob.