HELLO! So I got an RX8 and I love it! but I have a problem

I have a very clean 2004 with 94k miles. Bought it for $2,000.00

It does have the hot start problem which I am trying to fix with a can of engine restore. I have seen a few testimonials of people saying it fixed their low compression issue after a few hundred miles.

First what wasreplaced within the last 30 days

Radiator + Coolant
Thermostat
Fans
Plugs
Coils
Oil
Also decarb
(Dealership did it all)

Tomorrow, new starter

Now MY Rx8 is overheating when I sit idle... the engine feels like it is running pretty hot all the time. The fan is blowing hot air right into the air filter, i feel like that could be a major contributing factor.

I thought about getting a pipe and extending the air filter to the other side of the radiator where the air is not blistering hot... or re routing the air from the fans. I have NO idea what to do or why this is happening.

 

What intake do you have that has the air filter there?

It is unlikely you will have much luck with the engine restore treatment...won't hurt anything but low probability that it will work

Why did they replace most of the cooling system?

 

As you see the fan and filter are almost touching... the orevious owner had overheating problems and replaced the radiator and thermostat. It was still overheating and I noticed one fan was not working so i got new fans. Now it is still overheating. <br/><br/>THANKS!

 

You're missing some intake parts, amigo. I would buy a stock intake from the for sale section, or a real cold air. The AEM is very popular, as is the racing beat. You can find the intake for sale when people go forced induction. Or try a junk yard. I did it last week for a steering wheel. Lots of fun.

There is a plastic tray designed to prevent what you're seeing. The tray runs horizontally from the radiator, and sits on that gray colored piece of metal under your current air filter. There is also an air box with a large filter, and then an intake plenum that goes through the bumper and across to passenger side. Someone gave you a cheap *** intake. Sorry!

You may also be missing some screens, they are vital to the MAF getting a good reading.

 

Oh wow!!!!!!!!! That hole that looks like an Intake should pass through it is exactly what I was thinking, I had thought, I will just pass a pipe through it and get an elbow and reattach the filter on the other side. So I was not far off in my assumption. I am kind of broke with all these repairs, I might have to hit home depot and make something my self for a few weeks till I can buy a legit intake. I live in Hawaii so not a whole lot of options on an island

 

I hate to be the bearer of bad news. The good news is you can be up and running for a few hundred dollars. You got a good deal on the car, but idk what the dealer charged you for all that service work.

I forgot! Welcome to the club. Folks here are very smart, you just have to ask the right questions, and search around if you are curious about something .

Start here:

https://www.rx8club.com/new-member-f...ot-8-a-202548/

 

If you make your own intake (not the best thing, but better than what you have!) two things are important. You must use a screen or two to "smooth" the airflow, and do not change the diameter. You need to keep the tubes nice and fat.

The AEM will drop right in, you just move some wires over. It costs 362 bucks, they even have it on amazon Prime. You will need to remove the bumper to do anything, because you need to get air that is away from that big hot radiator fan. Ideally, that air is in front of your engine bay, hence the term cold air. For what it's worth, they even sold the AEM as a Mazda accessory.

Best of luck, and don't hesitate to come back to this thread, there are a lot more "experts" around.

 

If you are having idle issues the intake is likely the cause. The MAF needs to be in an area with laminar flow...that bit is way too short and you will have turbulence at the sensor for sure

 

Yeah I am having idle issues, it bounces between 500 and 1500 rpm. Excellent information here. I will buy the AEM intake after I get a job, for now I will do some makeshift piping.

Is it necessary to put any insulation around the pipe were the fan is heat blasting the intake? Anything in particular the fans should be blowing into? Should I re route the air?

 

All I can tell you is that there is a shield that normally separates the two areas. Even extending your intake into the hole in the front bumper would improve your situation.

I don't want to mislead you and say the AEM is the only way. This is most of what you need

Mazda RX8 Air Cleaner Box at from Vin 100486 04 | eBay

That will get the air away from your hot, nasty radiator fan. It will bolt up where your intake is now.

This is the other half, which sits in front of your bumper

RX8 Manual Air Clearner Inlet Hose Assy | eBay

Lastly, this is the heat shield that separates the radiator from your air box. Hot radiator bad. Cold air box good.

http://www.ebay.com/itm/04-08-manual...3D191579730030

Those three, a new paper air filter from your Mazda dealer, should get you up and running.

 

So I went to home depot and I extended my intake to the front of the radiator, I ran the AC and the car started to overheat so no more of that. After about 30 minutes of driving, it started to overheat on its own. it released quite a bit of coolant so I have to go buy more.

If I purchase those original pieces, will that fix my overheating? If not what other underlying issues could be the cause? well moving the filter to the front of the radiator, under the bumper did make a substantial improvement. but she is still running hot.

Does everyone have those original pieces installed? They are that crucial to the cars operation?

EDIT* I found a guy on ebay with a crashed RX8, I am asking how much for the entire intake assem, after the sensor. Hope I can get a good deal.

 

Yes, we all had those intake parts. It is very important that the intake air be smooth and predictable, otherwise the MAF will not get a good reading. This will cause stumbling, uneven power.

I think the lower tray is causing you trouble, because the hot radiator air is getting all over your engine bay. I cannot stress enough how bad an overheating RX8 is. The engine runs hotter than a piston engine. It is also a compact engine block, which makes it run hot. There are many seals and gaskets in the engine. Heat is the enemy of seals and gaskets. A leaky seal, or God forbid a coolant leak, and your engine has minutes to live. If it overheats, pull over immediately.

Now, back to the topic at hand. You may need to drive the car, and let it "relearn" your air fuel maps. You can reset the memory by unplugging the battery for half an hour. Since you changed the intake ( nice quick work, by the way!), you will need to reprogram these maps. The car does it automatically, it just needs enough mileage and varying throttle conditions to learn it all.

When is it overheating? Stop and go? At idle? The AC compressor does place an additional load on the engine, so you might be pushing it past its comfort level.

 

It overheats when the ac is on, when I push high rpm, and when im stuck in traffic. Sometimes the needle will go back to normal. It will budge forward a bit and scare the living hell out of me. Today it budged forward twice and went back to normal but the last time it started moving forward with no signs of stopping. I immidiately pulled over and popped the hood. Let it cool down, it was vomiting coolant. No steam or any of that boiling overclow business.

My fans are 800CFM... is that enough? Also yeah the fans are blowing hot air all over the engine bay. I gotta fix that somehow.

 

800 isn't enough, the overheat conditions you're experiencing are from to little flow through the radiator. The issue is a combination of your fans not flowing enough when stopped, and your fan shroud+fans blocking top much air flow while you're moving.

Are you running the stock fan wiring, or are they always on?

They blow hot air all over anything anyway, it's a pretty shitty design for that part. The battery is in the way, the intake is in the way, it's all a mess. I really like your new intake! Heating it up is a concern but it's light years better than what you had, good work!

 

They are always on... oh that is a shame, I just put them in too... how many CFM do I need? Combined they are pulling 1600... oh this is becoming quite a nightmare scenario for me. Haha a money pit of sorts.

How much air donthe stock fans pull? Each or combined.

 

Toast

I am looking at your engine bay. I see a splice in the coolant line. The line runs directly above your battery. Do you see the 90 degree fitting? That is not stock. That looks like it is an aftermarket cooling accessory. It was designed to turn the fans on early to prevent overheating. If you follow that 90 degree fitting, you should see wires running down the bumper, and towards the fuse box. Can you confirm?

I wonder if that has malfunctioned, and your fans may be turning, but not at full speed. This accessory explains them being on all the time. Stock fans don't come on until temps are nearly 200.


@ Legot, he said the dealer replaced the fans. I know dealers screw up, but putting in the wrong fans?


Toast, are you getting any check engine lights?

Guys, is it possible that his cooling fan control kit has gone bad?

 

Maybe it is broken, I don't know. The stock fan control is pretty much the best possible method in terms of reliability.

I think what really needs to happen is an engine bay teardown/cleanup to figure out what's actually been done to the car, and to get everything clean and not disgusting looking.

 

I agree about an engine bay clean out , but the OP is at the end of his budget, and might be out of patience as well. At this point, a sheet metal tray to seperate radiator from engine bay could be the cheapest solution. If he is recycling hot air, it's going to overheat in a hurry.

 

Yeah i got a check engine light.

 

Thank you for all the posts,

Yes the splice, i saw that early on and watch a youtube tutorial on the little device. It said the fans should remain off till a certain temp but they don't. Should I remove it? Buy new fuses? The fans dont seem to ever change speeds.

I can get a hose to clamp over the elbow i guess. I was suspecting the kit went bad.

Tomorrow i will create a barrier to stop the fan from heat blasting my intake. Where should i direct the air flow? Down under the car? You guys have been so helpful and it is really appreciated. I was going to have the engine detailed but i ended up putting about 3 grand into repair and sorts.

And yeah I got a check engine light.

 

The Fan direction is normal like stock
(I'll go get a picture from my car)

What's not normal is that fan shroud which I suspect is doing more harm than good.
Also if you don't have the flow straighteners you can use metal screening.
I can't remember the size, gimme a bit to go find it.
(will insert pics here)

Other thoughts are:
- What the heck is going on over by the Bara-Sensor with that wiring and cooling hose t-splice
- Water Pump?
- Looks like there was a Throttle Body by pass done, hard to tell in the picture.

You've got a real dogs breakfast there (In Canada a dogs breakfast is when a dog pukes then eats it again .. yum)

I'm with Legot, start tearing stuff down to figure out what exactly is going on.

Nice work on the Intake, tho I might have tried PVC or Aluminum tubing (both should be available to you)

Please keep us informed, I think you've got a good thing going and members honestly trying their best to help.

 

The intake piping is aluminum, just flexible. The splice in the coolant line is a kit someone else installed before me to make the fans come on at 190f but I think it is broken since the fans stay on. I am unsure what you mean by "fan shroud doing harm" please explain that to me. I am unfamiliar with the original engine bay configuration and parts.

I will take more detailed pictures tomorrow so everyone can get a much more profound understanding of what they are looking at. I would love to do a tear down if I had the budget or knowledge of how to do that. Best I have right now is you guys here.


I live in hawaii, so that would explain no sunlight here for a few hours. (pictures)

 

Right ignore the bit of a mess I got going on .. I need to relocate that red battery cable (not stock battery is in the rear)

You see how the OEM shroud is plastic yours looks like metal and the OEM fans look bigger, maybe or just illusion of picture.
I don't know. You're probably right it isn't an issue but it different than stock so I guess it's just good info for you.



Flow Straighteners
Product photo closeup

Wire Screen link and discussion : enjoy
https://www.rx8club.com/series-i-maj...e-mesh-183505/

 

Your fans do look bigger, i dont see your intake. What intake setup do you use? Do you have a lower heat shield?

How many cfm is your fans? Is the air flow directed or donthey ju add t blow air all over the engine bay?

 

This is my attempt at a makeshift heat shield, I have spent all my money and I am getting desperate to end this overheating issue. This should prevent the fan from turning the intake molten. I am not sure where the air will go.

Please let me know if I screwed up and if adjustments need to be made. I did what I could ...