gjrod720

I have searched and searched when I get the time for months, I can not find anyone else with this issue.

My engine coolant levels are dropping quickly... I have had an AEM cold air intake installed on my 2004 rx8 for about 2 years now, and that is my only modification. This JUST started happening a few months ago, and I'm getting tired of replacing my coolant every day or two...

I've noticed when the engine gets warmed up and up to normal running temp, when I cut the ignition to stop driving I'll get out and see a pool of coolant just dripping on to the ground (and the car smells strongly of coolant, even standing 20 feet away from the car lol...)

I've also noticed little splash marks of coolant all over my engine bay as well... With the CAI installed, I see the coolant overflow hose is not connected to anything, and I feel like that is where the coolant MAY be leaking out of... Is there ANYTHING I can purchase to plug that off? Maybe a catch can of some sort? The original air box plastic guard underneath where the old air box used to be is still connected to the engine bay. (I left that on for some unknown reason.)

I could very well have a leak anywhere in the actual coolant system in itself, I just feel like maybe that overflow hose has a big part to do with this problem, and I am wondering what you all here may think about it.

Any help or suggestions are greatly appreciated!!! Thank you!

xexok

Do NOT plug your overflow hose... Horrible idea lol.

You know the problem already, you stated it in your post. You have a coolant leak, that is where your coolant is going. You just have to figure out where the leak is coming from, and that is something that we cannot do for you unless we are there to inspect the engine bay.

Look in the engine bay and start looking around for dried coolant. Follow it from where it drips up to the source, you should have enough room in the engine bay to see with the CAI installed. I found a lot of posts about coolant leaks, maybe you were not searching for the right terms. Google this site:www.rx8club.com coolant leak

gjrod720

LOL! Thank you for advising not to plug that overflow hose. I will most certainly NOT do that now.

And thank you for slapping some common sense in me with your post. I just wasn't sure if it was the overflow hose that it was all leaking out from or not. Now that I know it is not I will be looking again for leaks elsewhere...

Also for some reason I have a really hard time using the search function correctly on this site I guess :/ lol. Maybe with more practice I'll get better!

Thanks for your help Xexok!

SubliminalPollution

The coolant overflow through the little overflow tube was happening to me also. Also my temperature gauge would read right at the middle, not slightly to the left as it normally reads. I would run my car normally and once I turned it off the radiator fans would turn on because the the radiator was hot while coolant leaked out of the tube, hitting the fans thus spraying coolant ALL over the engine bay.

It turned out to be a clogged radiator. I had the radiator, lower radiator hose replaced and the problems both disappeared.

RIWWP

iTrader: (2)

If you think it's overflow, find a small bottle and stick it around the end of the overflow, and secure it in place. Make sure this isn't sealing anything. If you have coolant in the bottle after driving, you know that the overflow is on point.

You haven't mentioned leaking coolant, but if its not overflow, the start leak hunting.

The only other source is into the engine if you have a warped housing and or coolant seal failure. But that much coolant loss into the engine should be giving you lots of white exhaust smoke.

missinmahseven

check waterpump.

gjrod720

I will secure a water bottle while I'm at work today to the overflow hose without sealing it, and see by 2moro how much coolant is left in there to determine if the overflow hose is doing its job... I've gathered if there is nothing in the water bottle then it's probably leaking from somewhere else. What SubliminalPollution said sounds extremely similar to this problem though... It sounds like I might have to replace the radiator lol. I'll keep you all updated, thank you SO much for the advice everybody!

SubliminalPollution

Glad my previous situation was able to help. On a side note it was a Mazda dealership that recommended the new radiator and lower radiator hose. I know forum members say that dealerships don't know what they're talking about at times, BUT it was the mechanic that personally told me because he is the only one in that dealership that ONLY works on rotaries.

No one else wanted to touch my car.

RIWWP

iTrader: (2)

There are other places it can block at. Thermostat is another common one.

I'd be careful. Overheating this engine is very deadly to it. Warp a housing and you are done.

gjrod720

I replaced the thermostat about a few months ago because of overheating... Now I am trying to remember if the coolant was leaking out prior to that... Changing that thermostat was an absolute pain (no room to move your hands lol) , but definitely stopped the over heating issue...

Shortly after that I replaced the coils wires and plugs which took care of the trembled start up and idle/stalling...

With the coolant spewing out all over the ground now, the temperate is just a notch higher than normal operating temperature, but not at all overheating which is definitely a good thing.

I also noticed my idle runs around 900 rpm normally but when my air conditioner is running my idle will drop to about 750 rpm :/ I am also wondering if this has anything to do with the coolant issue... Does anyone think that the lower idle w/ A/C is corresponding with the potential failure of the radiator?

(Once again, thank you all very much for your help! I really do hope this post helps any one else with this issue.)

SubliminalPollution

Oh yeah I forgot to mention that my thermostat also was replaced when I got my new engine. My car never overheated or went past the halfway mark but it did run hotter than normal and the needle stayed right in the middle of the gauge.

Wouldn't the drop in RPM's after turning on the A/C be a grounding issue?

RIWWP

iTrader: (2)

Lower RPM with A/C on could be a grounding problem, but not necessarily. If anything, turning on his A/C puts his RPM where it should be.



And OP, just so you are aware, if the needle moves AT ALL upwards, it's usually already at a critical temperature. One of Mazda's design faults is that the temp where it starts moving it too high, and for many engines, already too late.

Harlan

iTrader: (3)

Take the radiator cap of with the engine cold then start the engine. If you get surges/bubbles you have a blown coolant seal. If that's the case then you need an engine rebuild.

If it is severe enough it will prevent the coolant temp sensor from reading right, and in turn prevent the fans from running.

Also several people have had issues with the rubber grommets from the air box falling and stopping coolant fans. So if both fans arn't blowing right that could be a cause.

xexok

I need to remove my airbox and search for that rubber grommet then, one just disappeared recently.

OP another thing to think about is if you do find out its the overflow hose is cleaning your power steering connector because when that hose spits out coolant it gets on that. Could cause you some problems down the road if thats the case.

Karack

test and or replace the expansion tank pressure cap, if it persists then you may have a costly repair on your hands.

gjrod720

So yesterday I connected a water bottle to the overflow hose and drove for quite some distance, nothing overflowed into it. Today I connected another water bottle on JUST to be on the safe side.

I topped off my engine coolant reservoir and started the vehicle for the first time after letting it sit over night. I started the vehicle with the radiator cap OFF, and watched for any bubbles...

During the first 30-45 seconds of the car running, I saw on the top left hand side of the coolant reservoir what looked like a gurgling of coolant being sucked up by an upper left hand hose (probably the water pump sucking up what it needed due to the lines being empty from the coolant draining due of the leak). I did not see any bubbles during this process.

After about 30-45 seconds, the pump stopped sucking up coolant, and the car ran at an idle for about 5 minutes while I was checking ALL hoses and areas for leaks.

I believe I found the leak, and what else I found was quite disturbing... an ORANGE build up of what looks like sludgy yet dried up coolant!



Uploaded with ImageShack.us

(I will try to attach better and clearer pictures later tonight).

I am not too sure of what hoses these are but my GUESS is they are two 3 inch hoses that connect to the radiator... They are located 2 hoses below the top hose that connects to the thermostat.

Sorry I am such a newb and not all too familiar with the names of these hoses or parts, I tried looking for a diagram of the engine bay on Google but nothing came up. On the housing for these two hoses, "N3h1" is inscribed on it...

Has anyone else seen this before? lol

gjrod720

Normal operating RPM is 750? Really? If so that gives me a slight piece of mind... When I turn the A/C on and the rpm drops from 900 to 750 rpm, I sometimes get quite a bit of a shaky idle... I always thought this could be a problem.

Also, It's good to know about how critical keeping this engine cool really is, even if its a slight temperate increase. I am glad you pointed that out... Hopefully this isn't affecting my engine like so... If it is, it must be a slow and painful death, it's been this way for months.

RIWWP

iTrader: (2)

it's closer than 900 rpm for a normal good engine with normal ignition. Should be 800rpm. The tach isn't precise, so a 750 is more likely to be accurate than a 900

200.mph

iTrader: (9)

not always. i thought this also but after flushing my system some crap plugged my t stat. there is a chemical test to determine if you are getting combustion gases into your coolant system. mine past with ease

Karack

you're not using red coolant are you?

gjrod720

I had used a cheap red coolant one time, I was low on money and that was when it started leaking and I just went to the store and picked up the bottle................. Good lord this isn't the cause of the problem is it??????

TeenMike91

iTrader: (1)

I really think this is a defect in our cars. Only because My sister has the same rx8 as me but hers is a diffrent color. Anytime something broke on my car, her same part broke shortly after and vice versa. Both rx8's are 04's.

Take your air box out.

Take the bottom tray of the air box out.

Look back by the top of the cooling fan shroud

There is a large coolant hose coming off the top of your radiator. And a small one right next to it. The small nipple that is molded to your radiator i bet is dry rotted and is cracked. The hose will look perfect and it will look like there is nothing wrong with it. Just grab the little hose and move it with small force. I guarantee you that nipple breaks off without barely even putting force on it. It is not suppose to break that easy. Mine did it, and my sisters did it.

I had spray marks all over my engine bay. I traced the spray marks. They were coming from in between my air box and by my coolant overflow hose. It was not the coolant overflow hose which is what i thought too.

My suggestion to you is to pull that little hose back and forth with some pressure. When mine broke off, it was because half of it was already cracked. But I couldent see the crack, but when you are driving, the PSI goes up, which opens any little invisible crack you might have in the system, when mine would idle, it wouldent spray, it was after a fast drive or prolonged idling that it would spray. You can also smell it in the car if you are sitting at a light or even driving on the highway. At least I did.

Hope this solves your problem. It sucks to have such a nice, fun and perfect looking car that has so many defects and recalls. I still battle with mine monthly on repairs. But its worth it to me. The best car ive owned!

TeenMike91

iTrader: (1)

Also, for future reference. I have the entire rx8 schematic for both inside and outside the car. It covers every part for our cars. Its in PDF format. If you want it, PM me with your email and I can send it to you to have.

TeenMike91

iTrader: (1)

Just figured out I can attach it here! your new to the parts of the car and im new to this forum and how it works. lol. Here you go. Sorry for so many posts.

redline86

iTrader: (7)

Just about any part of the cooling system can fail, hose collapsing, thermostat stuck, water pump gasket leaking, the radiator part as mention above, the reservoir from age cracks. These are problems that can be encountered in any older car. Your car is 8 years old and has seen 7 or 8 Florida summers depending on when it actually arrived in state. That heat does bad things to rubber, as well as other components. If you plan to keep the car for several more years then I would (if you have the money to do it) replace every component in the cooling system.

https://www.rx8club.com/series-i-trouble-shooting-95/redline86s-coolant-issues-plus-major-summer-project-218810/

If you have a little mechanic skills it isn't hard to do yourself, just time consuming but will save you a lot of money.