chueytom3

First of all thank you to anyone who reads this and provides me with advice. I just recently bought a 05 rx8 with 60,000 miles on it. Everything in the car is original, it's never been worked on. I have a coolant issue. My resevior tank is empty yet when I fill it up it just spits what I put in there out after turning the car off. I noticed that after driving the car and turning it off that if I pop the hood I can hear air escaping from the bottle. The car is not running hot, the temp gauge in the dash never goes more than half-way. I've replaced the radiator cap. I can smell coolant almost every time I walk by the car. No smoke and no overheating. What could be the issue? I'm leaning towards the bottle itself. Am I wrong?

DeViLbOi

iTrader: (1)

Not gonna be an issue with the bottle. Most likely you are looking at an issue with the thermostat not opening at all. You also want to check for pinched hoses while you are working on it. Also once you put coolant in you need to get the air out of the system that was sucked in after the coolant was gone.

FYI: The coolant gauge on the dash is a 3 position dummy gauge and by the time it moves you're toast.

Mazurfer

How full are you filling the bottle?
There is a full mark on the lefthand side when standing in front of it.
It's just a thought, but the mark is only about 1/4-1/3 the way up the bottle and a bitch to see.
If you are overfilling and it's not your thermostat, then you better quit before you start having power steering issues as coolant is running all over those connectors!

chueytom3

Im not overfilling it by any means, I know where the lines are on the bottle. The last time I added it when the engine was warm. Is there any other signs I can look for to know if it is the thermostat or not?

DeViLbOi

iTrader: (1)

There is a DIY on testing a thermostat that you should do. There is nothing you can inspect...you just have to test it.

chueytom3

it just seems weird to me that the temp gauge is not moving to suggest that it is the thermostat, is there any other signs that it could be the thermostat. After letting the coolant spit out whatever i put into the resevoir tank, the car never leaks coolant. I've driven it 600 miles with the resevior being empty before. This is why I don't think it's the thermostat.

Mazurfer

Sorry, had to check. You'd be surprised how many people fill it all the way up, then put the cap on and wonder why it comes shooting out!

Oh and like was already said. That temp guage in the car is pretty useless.
I know you think it should move, but it really one has but three positions. I don't think you can really use that to look for a stuck thermostat. Maybe if it was stuck and you ran the **** out of the car or had no coolant at all, but that's about it.
AND........it would not be good to do so......obviously.

DeViLbOi

iTrader: (1)

Yea..I sure hope you didn't run your 8 for 600 miles without coolant.

DarkBrew

Bottle or cap? Hose clamp?

Do your cooling fans operate?

I would get an ODBII scanner and check the temperature.

I was watching the temp gauge while tracking coolant temp with the AP: The gauge starts to move at 120 and sits at normal (slightly below half) by 150 or 160
After that it doesn't move....
I've heard it will move up just before the engine detonates.

I also noticed that after shutdown the temp can rise... sometimes the fans come on.

ninjajim4

iTrader: (4)

i'm in the same boat as you, OP, but i never got a satisfactory answer to my question. experience the same thing, coolant overflowing, and that hissing sound, even though i've a new radiator cap as well. i DO have my car PC hooked up and see an average water temp of 210ish. it can get as high as 220s in stop and go traffic, on hot days with the AC constantly running. all of this tells me my coolant is circulating, tstat is ok, and i can hear my fans working

none of this is considered overheating at all, but within this range, i am still seeing overflow. i've at least got a CAI and so i just flipped the little tube over the edge of the airbox tray, sparing my connectors from corrosion.

i will likely do a coolant flush next. looking forward to hearing about a resolution

Mazurfer

^..........you sure your fans are BOTH operating correctly?
Yes, I have the old mazsport cooling fan mod in mine, but I do monitor my temps, I'm in Florida(+90 most of the time), and honestly I don't hardly see +200 degrees.........even in stop and go. Now to be honest this is with the car seeing probably less than 1 hour of total run time, but I can be running it pretty hard during that hour, even in stop and go.

Razz1

Umm... this is interesting.

Try burping her.

Put up on jack stands.
Take off cap.
Start car let her run until she boils.


I still bet you have a bad thermostat or water pump.

When cold grab the fan and see how hard it is to turn.

If real easy you need a new pump.

Sounds like you are riding on the border line.

Usually you can flush the system out. Sounds like a clogged radiatro or heater core.

So I would just flush, burp, and wait for results. Maybe even replace the thermostat.

If your car has alot of miles I would replace the pump and all the hoses.


Also, if you just add anti freeze....... Your mixture is incorrect.

Too much anti freeze will cause the system to boil over.

Pick and choose... Good Luck.

ninjajim4

iTrader: (4)

that's something to check.. but i don't know how valid a comparison it is, given that you have the fan mod. i don' t have it myself, but i've read that it works fairly well. so i would expect that your running temps would be lower than mine.

regardless, even at 215-220, would one expect the coolant to be overflowing?

DarkBrew

I've never seen mine that hot...

But I'd say no way!

Where is it spitting it out? Through the tube? or somewhere else?

ninjajim4

iTrader: (4)

yes, it just goes out through the overflow tube. i didn't realize that my temps were outside the normal range. given that the tstat is fully open at 212, i thought this would be about average

DarkBrew

Have you changed the cap on the overflow bottle? Have you checked that the bottle seals to the cap?
The highest I ever saw my temp was 100C or 212F

I'm running Cobb AP with MMCCS so my fans come on earlier now.

Renesis07

iTrader: (1)

212 isn't average. My car hovers at 180 - 195 (depending on weather), If I row through 1st-3rd gears WOT Itll go up to 200-205 and go right back down when I resume normal driving RPM's/Speeds.

Highest I have recorded is 208 and that was in traffic in 100 degrees.

210+ degrees under normal driving conditions would definately raise attention in my eyes.

My RX8 only has a K&N hot air intake and a ram air duct, other than that it's fairly stock, no cooling mods.

BTW, according to numerous sources that I've talked to, the dummy OEM gauge will spike at 230 + degrees. Just what local rotorheads have said around here. By that time, you're running some serious risk of damaging your motor...

ASH8

HUH?..Grab the fan??

ASH8

OP...what others have suggested... the Cooling Fan Motors (2) appear to be slowing down with age/use, even not working at all and need replacing...as Dave said..I would be checking the Electric Fans that they are working..

WHY?..they are being slowly "cooked"...

ninjajim4

iTrader: (4)

i pulled the intake tray and took a peek underneath while running. both of the fans are blowing away hard...

i will be doing a coolant flush and likely change out the thermostat as well. i would be very curious to see if this made a significant difference. as i've been refilling, i've just been putting in straight water in the hopes that mix was off.

thanks for posting the water temp numbers. i have had nothing to compare mine to

Mazurfer

Not with it running mate!

04Green

iTrader: (1)

Original problem sounds like the car has a ton of air in the system. I have not seen this with my 8, but have on old mustangs and other big V8 cars. The air needs to come out. That is the burp process. If it was me, I would open the cap, fill with water (to full line), leave cap off and start the car. Let it warm up at idle, and see if water is moving. It should not be moving when the engine is cold (thermostat is closed), but you will start to see movement when the thermostat opens. An expectation is that somewhere along the way the water in the reservoir will suddenly disappear. If that happens, fill it back up to full line.

I assume the fans are running, you should be able to hear them.

Some of what can be happening is that the temp sensor is not in water, but is steam. In the old days, they did not measure accurately that way (they read low). They may be better now.

Your blast of coolant could easily be driven by too little water, all of it boils when the engine is off, and the steam blasts what coolant there is out of the engine, and into the bottle.

That is the best I got right now.

In my sig is a link to cooling stuff to do when you get the car (first $100). There is a link on the first post for an area for new and pre owners. It is great as well.

Where are you?

Mike

ASH8

Read what Razz1 said..."grab the fan and see how hard it is to turn, If real easy you need a new pump."

Huh??

I think he is talking about the Water Pump Belt Pulley...where there is no FAN to Grab..