DIY: Replace your Radiator (aftermarket or OEM, both the same)
 

Another one of my sucky DIY.

Im not going to bother with all the tools that you'll need, as a DIYer. You should have at least a set of wrenchs and sockets of all different sizes (or at least from 4 mm to 28 mm, and SAE size from 1/32 to 1-1/8")

Oh also, before you start, have a copy of the service manual around you(or at least read it like 10 thousand times b4 you start)

You will have to take ALOT of bolts out, so make sure you have somewhere to store them so you dont lose them.

1. Make sure your new radiator has no leak. how to check ? What I did was I use my tire compressor, Have some tape to connect it top, tape shut the coolant reservoir mini hole, made some Soap water, spray it all over the radiator. turn the compressor on, check and see if theres any air bubbles coming from ANYWHERE of the radiator. NO leak? ok, you have a good one, flush it with water to get ride of the soap. You have a good radiator so dont break it now.
2. Take the Intake Box and Battery box away, COMPLETELY. do NOT even think that you can skip this step. Notice : the Battery Box has 3 parts, the cover, the middle part, and the bottom part. cover of course just pull it away. The Middle part is hold by couple of plastic clips on the side, easy on them dont break it. Then you will see 3 bolts, 2 on the side, one at the bottom of the battery box. Just take it all out. See all pictures.
3. Open your ECU cover, take the ECU cooling duct on the right away(the one that connects to your FAN
4. Loose the Coolant reservoir Bolts, theres 2. You dont need to take this out, you have to move it away from your sight later, but just keep it there for now.
5. Now you should have a clean engine bay.

6. Take the bottom cover out completely - Picture 1
7. Picture 2 - You'll find 2 bolts (one on each side) that holds the under cover in place, take it out with extension like me - Remember, theres alot of wires/clips going thru the sides, just un-clip it and take it off, they only go in 1 direction so no need to mark them down. You dont have to take the side mud guard down. Leave them there.
8. Picture 3 - This is what it looks like when your undercover has been removed, its racing beat screen there.
9. Picture 4 - Time to drain the coolant out, right under the bottom of the radiator, theres a tiny little plastic screw, just loose it, fluid will come out, be careful, if these thing splash into your eye run to the sink and water it. better to have eye protection or stay away from the openings as far as possible. Let it drain for 5 minutes or so, until it stops.

Optional move : theres another drain bolt on the engine itself. but I didnt use that. its not in the service manual. is a bolt on the side of the engine.



Got something to do, to be contiune.

(You can follow the shop/service manual, it tells you exactly which goes first)

10. close the cap when the draining is done. but, you should expect to see more coolant later, because when you start taking the hose away. more coolant will come out from the engine. so prepare.
11. Take the hose OFF ! this is a really tricky part, because after all the mileage (I got almost 29K), the OEM rubber hose *kinda* stuck at the connectors .... is easier to take the engine side connector out, but expect to break *something* when you're trying to take the radiator side out .... well I dont really care if I break my OEM radiator cuz I wont use it anymore, but if you want to keep it, becareful.
12. After all the hose is OFF, coolant will spill, so make sure that you dont let them get into your eye.
13. At the top and try to take the fan's electrical wire off first, and there're 2 bolts at the top of the fan thats connected to the radiator, take them off.
14. Now take the AC Condenser bolts off, the A/C Condenser will not fall because the A/C line will hold it, but still be careful and try not to apply too much pressure to the lines.
15. to take the REAL Radiator brackets off ~ Start from the top, then the bottom, its easier that way. Look at the pictures.

16. After all the brackets come off, you should be able to slid the Radiator out. Notice : You should be very careful, because remember your A/C Condenser still hanging in the air, and your old radiator's top hose connector might come in contact with the back of the A/C condenser, if you apply too much force it might break it. so just be very careful.
17. When the old radiator is out, take the plastic groove from the bottom and top OUT, and install it to your new Radiator. (See Picture, Old radiator and New Radiator) and transfer WHATEVER you can from your old radiator to your new radiator, including all the FAN shrouds, foam on the side, etc.
18. After that, just install everything back in reverse order.

Thats all folks.

Is a bit confusing but .... if you have any ? please just ask me, pm or reply to this post.

Good writeup!

I just swapped out my old radiator for some new goodness and the instructions were fairly easy to follow

the hardest part was getting the old radiator out from in between the fans and a/c condensor but a bit of jiggling, pushing and pulling and a spare set of hands, i finally got it out!

the hard part for me was getting the bigger radiator in. lol true though, an extra set of hands woulda made it easy.

ok i just did this install and i thought i would add a couple tips. i figured since its a write up its ok to bring it back from the dead...

first is i took the rad out with the fan still bolted to it, you'll know why in a min. make sure you have a friend there to help slide the rad out, the reason is its very easy to damage the condenser when sliding the rad out, you should have one person up top and one person underneath.

once the rad is out set it beside the new rad and remove the fan. i was installing the ron davis radiator so fitment may vary between rads but try bolting the fan on and look for gaps on the top and bottom of the rad, the fan should seal tite against the rad to maximize the fans ability to pull air thru the core, air will always take the path of least resistance so even a small gap will decrease cooling abilities.

the ron davis has quite a large gap at the top and bottom the whole way across its about 3/8 of an inch. so i found a PERFECT fix for this, i took a piece of semi soft rubber hose I'm not sure of the size but the outer diameter is slightly smaller then a nickel,the trick is to find soft hose that will squash easily when you tighten the bolts, your gaps will probably vary anyway so experiment with different size hose.

cut the hose to length for the top and bottom and set the fan on top and squeeze the hose into the gap. if you find the correct size hose it will fill the gap perfectly and you shouldn't have to draw down the bolts in order for the fan housing to contact the rad (don't force it). and then it should be all sealed up perfect. then with the old rad next to the new one note the placement of the foam pieces on all 4 sides. now go buy yourself 3 or 4 small tubes of super glue,do one piece at a time, cover the edge of foam with the glue and have a friend help hold the long pieces on. the super glue works surprisingly very very good. now your all ready to reinstall the rad.

i hope these tips help out, good luck

k, so what do you do with a new alluminum radiator that has no mounting holes or anything for the top mounts or the ac condenser? Oh and that also doesnt line up with the fan assymbly??? got me...

buy some 1/4 inch steel stock, get nice metal chop saw , a good drill and some nice bits and make your own brackets/ mounting holes. with enough modification you can fit any rad in there...is it worth it..probably not. what rad do you have?

Nice write up thanks.
I've got a moderate coolant leak that needs to be investigated and I'll be tearing everything apart next week.
All I can tell about the leak is that its coming from the upper area.

i just did this today and when i went to start it up my 8 wont idle, it starts up then the idle drops to 0

any idea whats going on?

Either coils, plugs, TB or engine going bad.

No Im not kidding.

just replaced my coils, so its not the coils

i found out my friend hosed off the engine bay while i had gone inside because he spilled coolant, could that be whats wrong?

unless the water got into your intake (unlikely, unless you directly feed your intake with water)

Or a bad ground....

took it into the dealership
bad throttle body

so the front bumper doesnt have to come off?

^ ummm, no, but the undertray must be removed.

Hmm.. I need a new radiator, hoses, therostat, and water pump.. The shop is charging me with atleast 5 hours ($60 hour) = 300 bucks the cheapest..
How long could this take If I did it?

If you did it? Based on the fact that you have already got a shop quote and you have to ask, I am guesing your experiance changing radiators, water pumps and t-stats is a little low. Sooo, it could take you a very long time. Honestly, 5 hours for an average rx8 mechanic is about right. Maybe 4 hours, but not much less. And I would be happy if Mechanics near me only charged $60 an hour.

The radiator on this car isnt the easiest thing I have ever changed, the water pump is pretty simple but the t-stat is desceptively difficult do to the location of the bolts and the air injection is in the way.

You could use the DIY if you want to tackle the job, have the tools, time and space to do the work. If you have done mods and other service on the car with no problem, you should be fine doing the job, but nobody will think any less of you if you pay someone to do it.

Well I have done few things. Pulleys, intake. Exhaust simple things. I have a friend that he's dad had rx7 and he always helps me and says it's easy. But there's where I'm deciding to do it or shop you kno? I kno I can do it. We changed a radiator in my stepdads old tacoma but I kno our car is alittle more difficult..

Looks like ill be doing this next weekend. Thanks for the write up.

I think they put a hole in my radiator after swapping my motor. Never had cooling issues before that.

or they just never bleed the cooling system right.

it happens ...

so do you not have any cooling fans or did you intentionally not list having to disconnect the wiring harness holddowns and connectors before dropping the radiator and then swapping it over to the new radiator?

I guess we can call it a semi-DIY thread :stickpoke

I ended up doing this this morning. Took me about 5-6 hours. It is quite a job.

Thanks for this DIY it was really helpful. Here's a few notes.

1. Remove the fans and mount them on the new radiator. It's to hard to get the radiator in with them in there.

2. The MIZU radiator i got did not bolt up exactly. It was about a 1/4 off on the top brackets and i couldnt get the radiator in the exact angle without damaging the AC lines, so i couldnt get it bolted on properly. I'm gonna have to drill my own holes and secure it another way.

3. If you have an AEM intake i had to loosen the "curved pipe" sections as it gets in the way quite a bit.

4. I'm baffles why anyone would make a radiator with plastic parts. The top nipple on the stock radiator with crack off. It's only a matter of time, especially if you live in hot weather.