OK, odd question, but a different thread mentioned it..

Do you have an undertray on the car? Can you see the radiator from below?

 

Overheating only at idle is almost certainly a fan issue. Both fans have two speeds, but I can't recall any literature staing what the correct rpms are for checking them. One of two things could be happening. Since they seem to be operating then likely either one or both of the fan motors are not getting up to the correct speeds due to internal problems or the high speed relay is not working properly.

Check the relay first, then think about swapping out fans if the relay checks out ok.


.

 

But it only happens when the sun is shining Team....................

 

Yeah, whatever ...

 

But but but, Mazda says FL-22 is good for 10 years/120,000 miles! The cars cooling system was untouched from the factory. It came with stock coolant. So how come it has rust inside?

By replace everything, you mean the coolant lines, water pump and radiator?


With the AC off, temp climbs to 213.8F fast (because that's when the fans go on high speed). Having the AC ON slows down that process, because the AC forces the fans to be on high. I will see if the temps drop with the AC off, although the system should be able to handle 93F ambient temps with the AC on

Yes I do All that foam around the radiator would've been pointless if I didn't. Yeah I was on that thread too


Yes! That's what I'm thinking. If it's only happening at idle, it SHOULD be a fan issue. The high speed relay works. I hear the fans kick into high speed. I will test the relays to be sure

How do I check the RPM of the fans? This is by far the best way to check if they're spinning fast enough.

Could age slow both fans down?

Since the grommet got stuck and jammed the fan, think it damaged the motor and caused it to spin slower? Permanently?


As crazy as it sounds, YES :P

The fans are perfectly enough to bring the temps down at night, or if it's cloudy outside.

I can idle my car all night long or all day if it's cloudy, and the temp would not go past 206F.

Fun fact -
I was idling for around 10 mins last night with the AC on, so the fans were on high speed. The temp went down to 199F and stayed there until the fans went on low (because the AC was getting too cool). But as soon as I started moving (15-25mph) temp would go up to around 208F.

Flooring it in traffic with the revs around 4000rpm would bring it up to around 219F Normal?

 

This is your basic problem.
"Mazda says".

Lots of people had to get new engines because "Mazda says" coils are not a regular maintenance item.

You should listen to the people with real world experience with RX8s, and have learned the hard way that a lot of what "Mazda says" is wrong.

 

I see. I have changed the plugs, coils and wires. My engine seems to be fine. It's just the coolant temps

I took the car out last night in 86F ambient temps, doing 15mph in narrow roads seem to bring the coolant temp up to 212F.

Idling would drop it down to 199F.

Normal??

 

thats kinda normal.

FL-22 is not some pixie dust, sure its a LLC(Long Life Coolant) thats just exact same **** like the Red/Pink stuff they use in a Toyota or the Blue stuff they use in new Nissan (just different dye) , change it every 2 yrs (I change it at least once every year) and u will see less crap.

I seen fan motor failure, As for ur previous questions, yes when an electric motor dies, it usually dies slowly, spining slower and slower till one day it completely stops.

on rx8, the fan, even when it's bad will look like it's on high speed, cuz it is on high speed, just not the high speed you want(slower than usual)

check it with multimeter, if it's not pulling the required Amperage, it's going to die. I tested a brand new fan motor it was pulling around 11 Amp, motor 1, YMMV

Look it up in FSM page 71, Engine Details.

 

 

Thanks so much!

That's brilliant. So the grommet jamming the fan could've slowed it down considerably? Yeah that's what I was thinking in the first place. Spins, but not fast enough. I just didn't have a way to test them.

What's YMMV?
I'm guessing FSM means Factory Service Manual?

Do both fans spin at the same speed/draw the same amount of power?

 

Gentlemen,

I know that "after cooling" (fan stays on after shutdown) happens when the engine coolant temp is over 226F. I know that this will happen in S2s if the engine compartment temp is too high.

My question is, on an S1, is this the ONLY reason a fan would stay on after shutdown?

 

One fan motor is MUCH bigger than the other, and draws more amps.

 

Harbor freight difital tach

 

Thanks! All this time I thought both fans work at the same speed. They both turn on together, right?

 

I've never seen only one running

 

Click on the link and read, all you need to know is there.

 

Brilliant! Never knew it was all in this.

Now, which one is fan 1 and which is fan 2?

 

Yeah it is amazing what you can learn when you actually take the time to read.

 

I do read. A lot. I just didn't know that this was the factory workshop manual. All I do in my spare time is read on rx8club.

 

Obviously

 

I really mean it I started this thread ONLY because I didn't find another thread with my problem. Which is, as weird as it sounds, overheating only when the sun is up.

 

How are you measuring your temps?

 

Everytime you say this God kills a kitten. Please help save the kittens.

 

see if this helps

https://www.rx8club.com/series-i-tro...0/#post4671058

 

Using an OBD2 adapter paired with the Torque app

Kill all kittens!

That's fantastic! Where did you get that diagram from?

I read somewhere on this forum that only the S2s have an engine compartment temperature sensor. Never knew the S1s have it. I will try to find that thread.

Also, an S1 fan diagram I was looking at a while back (different to yours) mentioned that "after cooling" only happens when the ECT is over 226F. Not 230F.