+1

and the foam only goes on the bottom of the radiator right?

 

No, there is some on the sides and the top. When the old radiator is out you will see. Basicly put a light under the hood of the car and look through the front. If you can see light around the radiator, seal it up.

 

I think I have some extra in the garage, I'll snap some pics. It's for garage doors I believe.

 

aw geez, looks like another project for my car, it doesn't overheat but I can smell coolant and it does run extremely hot. I think the smell is coolant that saturated parts of my car when it was leaking originally, (Mazda dealership broke the plastic piece on top the last time my car lost an engine, it was cracked but still holding until one I pulled on the hose looking for a leak and it just popped off in my hand) and it's probably running mega-hot as I was unaware of the foam issue and my current replacement radiator probably has little or none in place etc.

 

You guys are on the right track. There is an extra step you can take that will provide even more cooling.

Look at your entire air flow for your radiator. Start at the front of the car (before the opening in the nose) and follow it through the radiator. Anything that impedes straight air flow is an opportunity to flow more air through your rad. For example, there are some cosmetic pieces on the front of your nose. You could remove them if you chose. There are several openings PRIOR to the air reaching the black plastic belly pan---you could seal those up. Simple Duct tape will do the trick for all of us. Foam works great. Get some black tape so it's not obvious/hideous. As we follow the air THROUGH the rad smart eyes will see.......that the big stock fan has a restrictive exterior case which runs perpendicular to the back side of the radiator----guess what---this is a big blockade for Mr. airflow. What is behind that? Big stock airbox assembly and battery box. Get the idea? This is simple stuff that has been a given in racing and peformance circles for dozens and dozens of years.

Want to cool your SYSTEM even more? Don't just look at the radiator, look at the other cooling system---your oil system. Same things apply for the oil as do the water. Great air flow in, tape it up, low restriction, nice exit. Believe it or not, simply removing the black plastic inner fender liner for the oil cooler can help your water temps. The Remedy water pump has a much nicer impeller and works. Hopefully everyone can see that addressing a few areas can help the entire cooling system. Give it a shot. All good.

 

^^^^ Word.

 

"I smell coolant" is actually normal, simply because from time to time when the pressure reach the cap's level, it will burp some out.


again, just grab some foam and seal it up.

 

agreed.

Stock rx8 oil cooler comes with a little shroud to direct air flow into the cooler, but for Mazdaspeed bumper have to remove that shroud and use a crappy piece of plastic (need to cut to fit too) to "try" to direct air thru the cooler.

I never had any cooling problem when I had Mazdaspeed bumper (3 of them, long story, dont want to talk about it again), and I'm back to stock bumper for now (have another 2 bumper in garage never have time(money) to put them on), if one day I'm getting Mazdaspeed bumper again, I'm going to work at that area (oil cooler), just gonna seal it up good.

 

very good info.

Another suggestion for Chavy which I can relay due to it happening on 2 rx-8s the past weeks. Do not neglect the electric cooling fans. between 2004-2005 due to milage these units are starting to fail in my opinion. I had one failure reported on the main fan and a week ago another rx-8 had a failure on the AC auxiliary fan.

If a fan goes you can overheat and destroy the engine right away. make sure that when you replace the fan you inspect and consider replacing the motors. You can buy aftermarket motors for dirt cheap if you want to save some money and I can tell you that the motors are standard on other mazdas so it should not be too expensive. The OEM fan units are a bit pricey.

 

I realize this is an old bump, but I found all the info in this thread extremely useful.


Eric, are you suggesting taping over the holes circled in this picture of the undertray? Do those holes serve any other purpose?

 

Or you could just do it like the guys on Roadkill and strap the hood to the roof haha. I've got an oriellys radiator in my 08 installed the foam and it helps. Keep in mind I live in Oklahoma where it gets so hot the devil would say screw that. One thing I found that actually works is a product you can get at most local parts stores called water wetter and as a tech I've actually tested it in an 84 corvette which are know for overheating all the time. Also run it in my 8. By itself at 100 degrees outside I've notice a difference of around 13 degrees cooler than with out letting the car idle at running temp in the sun with a c on. That's a big difference. Have also installed a fan on the oil cooler that's electric with a kit that has an adjustable temp on off relay. And that also helped knock her down about 5 degrees. If you're dead set on a used radiator do yourself a favor and have it checked and flushed by a good shop before testing whether it's plugged or not with your car.

 

We were talking about this on another thread. Apparently it's bad to cover up those holes.

 

I can't find it anywhere, what is it?

 

Sorry for reviving an old thread. My friend is looking for a replacement AT radiator, and we came across this.


Is this a good buy? It's 1/4 the price of the original radiator.

 

How so?

 

it’s a 5 year old post

didn’t anyone tell you to never, ever go Full Noob ...
.