the other day i hit a retread on the highway and busted my radiator so i need a replacement. would i be better off getting an oem used one or an autozone/o'rielly's replacement?
a used one will set me back for ~130 and a new one will cost about ~285

 

Buy a used one from the wreckers.

 

If it were my car I'd buy the best thing I can afford, heat kills engines and the rotary is no different. If the difference is only a 100 bucks or so I say go with the a new one, small price to pay for piece of mind and not inheriting someone else's issues, I'd only buy a used one as a last resort if that.

 

Oem or Bhr. I dont know about the quality of the ones from autozone. I heard aftermarket Koyo has issues.

 

Buy my low mileage used oem radiator. https://www.rx8club.com/rx-8-parts-sale-wanted-44/oem-radiator-coolant-bottle-hoses-windshield-washer-bottle-07-6mt-15k-miles-214981/

I am not just trying to sell my radiator, the oem unit is one of the best performers.

 

Oops, you have an auto and I have a 6mt.

 

yeah thats the main point of this question. whether the quality of aftermarket replacements are up to par with a used oem on.

i have heard of issues with aftermarket ones such as koyo. bhr is way outta my price range. i'll prolly go for the used oem one from LKQ it comes with a 6 month warranty.

i was hoping someone that's replaced their radiator would chime in but thanks a lot guys

 

If you don't track and just use your car normally then an aftermarket one will be fine. Koyo makes a non aluminum factory replacement as well as there are others who offer a lifetime warranty so there is little risk.

But if you do track or drive aggressive in a hot environment then don't be cheap (like I did) and get the Mazmart or BHR unit.

Getting a used plastic tank radiator is just dumb in my opinion.

 

yeah summer is right around the corner and you know how texas summers get.

 

ok guys I have an announcement to make. Reason why all the aftermarket radiators do not work as good as the OEM is simple: They do not come with the surrounding foam or the gaps arround it are large enought to not direct fresh air flow to the radiator.

I had my stock radiator repaired with a metal tank on the top (broke of the top nipple so I had to fix it) and the car overheats slightly because when they welded up the top metal tank they took off all the foam surrounding. I am sealing up the sides with expanding foam and will test accordingly. Mind you I had no overheating issues at all before. Same radiator same everything. We do not need a rocket Scientist to figure out what is going on here.


A customer of mine did the same thing (radiator repair) but unfortunately he ended up overheating so badly his car due to a bad fan and now he needs an engine overhaul/replacement due to a coolant seal failing.

There has been several threads about this. So remember please seal up the sides and bottom of your new radiator if you want it to work like the OEM unit, no need for an upgraded unit or a magical solution. If you track your car the best solution in my opinion is getting a second radiator.

 

There is some truth here but I have seen some sad aftermarket units in terms of fitment so I doubt they cool that great.

That said, foaming up my Koyo improved the efficiently greatly so it is necessary to do this. I even zip tied up the under tray to the brackets that hold the condenser.

 

ah thanks that's what i was looking for.
i'm getting the oem used one from LKQ. apparently they have "high quality standards" in recycled autoparts. i'll update the thread when i'm done installing

 

+1

Even the stock foam is not that great when new and over time it gets worse.

I would never recommend a used OEM radiator except for low mileage 07or 08 units. Older and higher mileage radiators will probably have corossion and the plastic will be worn/weak from high mileage/heat.

 

Yeah, I wouldn't go that route man. The plastic gets very brittle due to the heat. At least an aftermarket unit will have a warranty and usually it's a lifetime free replacement. But........ If you like taking risks then more power to you.

 

All 2004 rads should be crapping out by now...get a new replacement and do the foam around it!

 

Yea knew this couple years ago and I'm still shock that there are still people *cough*9k*cough* didn't know about this ... well he knows just a short while ago

Anyway, I had Koyo (still have it in my garage), Mazmart (probably hit something underneath it has a small leak and I threw it away), they don't come with the surrounding foam that the stocker has. if you can't(or forgot) to get the stock foam off. You can always buy some at homedepot, its freaking cheap anyway.

Now I'm using Knight Sports Radiator that's made by Koyo, it comes with all the foam and tubes for 99% fitment. why 99% because its a 53mm core its much thicker than stock and it takes a bit of wiggling to get it fit.

Plus RB Flash, no heat issues whatsoever.


OP, I NEVER buy used Radiator. the money you saved (say, 100?) does not buy you a new engine. You have no idea if its clog inside, you have no idea what the rad(the donor car) has been thru. It could come from some idiots that never change coolant and it has a lot of buildups inside.

Store brand rad are kinda crappy, most of the time they're made from Brass or Copper, which is heavy as F---, I never seen the Rx-8 version but I figure its probably the same if not worst. if I'm you I rather just get a Koyo rad, then get some Foam and high temp Epoxy from home depot and call it a day.

 

several people knock down the koyo, yet I think it's not a bad option as long as the foam is in place, I'm sure most of the negative reviews are due to the lack of the foam. Again that is just my guess.

Chavy to be honest there is no cheap way around this fix. Remember it is not worth the cost of an engine replacement. And believe me when I tell you this, I really feel bad for my customer who about 2 weeks ago blew up an engine due to an overheating issue.

 

ok i know that I am contributing 0 to this thread and I apologize in advance, but I seriously thought that your OP said that you hit a "retard" on the highway. I'm at work and laughing so hard at my reading comprehension.

 

Hahahahahah. BTW tested my RX8 auto today with the foam in place and 0 issues proving that you can average 10 degrees difference at idle temps on a very hot day with ac on.

 

good thing i haven't gone through with this yet.
what foam are we talking about here? is there a diagram type thing around here somewhere? how/why does the foam make a difference? i found a new koyo for 185 shipped which is still cheaper than the autozone/oriellys/advanced replacement so i'll be going for that now.

 

I changed my radiator 18 months ago with a Mishimoto Aluminum Radiator. I noticed the foam surrounding the OEM Radiator but didn't bother replacing it once the new one was in. I've driven the car from Bakersfield to Long Beach during the summer of 2010 without any over-heating problem. May be I should "foam up" for this summer and see if the difference.

The foam in question.




New radiator without the foam.

 

great pics Grace_Excel

also there is strip between the under tray and the radiator. Everything has to be sealed up.

the foam really mostly helps on stop and go traffic were my car was overheating. As a matter of fact it overheated slightly one day I went to put gas. I was with the AC on waiting my turn at the pump and she slightly overheated as I noticed the needle move (it should not move whatsoever) turned on the heater and down she went.

Now with the foam, no issues.

if you loose the stips the messy solution I came up with was using expanding foam. Much better seal and you can paint black so it doesn't look ugly.

 

or (again), just go Lowes/Homedepot and buy them. its cheap, buy some epoxy glue while you're there.

 

yeah I found the perfect stuff for high temp applications at Lowes. It even has adhesive backing. It has been a while now and is standing up well.

 

My home depot sucks. The best I can find is some hard foam that you place on your pipes so they wont freeze.

Any pics of the foam you guys say is perfect?