rx8-druggist

Hey everyone - my 09 r3 started making this bubbling noise behind the glovebox a few weeks ago, so of course I did some searching here and it pretty much sounded like it was the Marbles-In-A-Can (MIAC) issue... the fix was apparently a coolant valve restrictor?

Anyways I went to Markham Mazda, the Service Manager John was great at helping me out however he handed me off to a pretty brutal Tech who was infuriating to talk to . They told me the tech was the best with RX8s at the dealership - hurray right?

First thing I mentioned to him was that the noise only occurs at higher revs, closer to red line to which he responded "Why you redlining it for?". And just about every 2nd sentence was something along the lines of that. I go out to show him the noise and hes like he has no idea and runs back into the shop, and comes out a minute later and says yeah we'll install the coolant valve then - but continues to yammer on about me red lining "oh I never red line my cars!" so I respond "DUDE its a freaking rotary man" by this point another service guy comes along and says "yeah why wouldn't you red line it?" which shuts up the tech. Except now he seems pissed off and starts telling me he needs a day to work on the car to install this valve, he needs to road test it etc. etc. And quite frankly I dont want this fat grease ball touching my car anymore.

Has anyone around here done this valve replacement before? If its not too difficult I'd rather do it myself or get a friend to do it for me...

9krpmrx8

iTrader: (46)

I think it's a PIA to install. Just let the dealer do it and mark your mileage down, etc. and give your car a very good looking over.

Maffu313

iTrader: (2)

I just realized my car had that sound a while ago too! but after i brought it into the dealership and they found nothing wrong, i took the car back, and the sound was gone. never came back again. *shrugs*

Mazurfer

Not sure why you would say this? Looks to be just a restricting valve placed in the line.
To the original poster...........see this thread and give it a quick read through.
Will identify the part number and location of where it goes. Most info starts at about post #12, but still worth a quick read!

https://www.rx8club.com/showthread.p...ght=owner+miac

Footman

iTrader: (2)

The question is... is this just a "sound issue" fix? Does having this fix installed actually affect any performance aspects of engine cooling since there is less fluid flowing?

In otherwords, is the MIAC just a "sound problem"?

Mazurfer

^...............not really sure Footman. Can read through that other thread and a couple of more. I would assume that Mazda did enough checking to know that it's okay........but you never know.
All I do know is I've been in a car that had it, and I'm glad mine doesn't(looks for wood to knock on) because I certainly couldn't take it. Sounds horrible!


Oh...........I now see you posted the same type of question in that other thread.

rx8-druggist

Interesting - thanks for bringing the thread to my attention - I have been looking around and haven't read of anyone complaining of issues with the restrictor installed. Then again I'm not really technically inclined so I don't know what the consequences would be if I tried to minimally limit the flow of coolant =S ?? maybe I'll hold off on it for now...??

Its weird, the sound in my car can be unbearable at times but other times only have a few burbles...

Footman

iTrader: (2)

^ That is the same as me. Sometimes, it's there, sometimes it's not.
I'm hesitant to install it without knowing whether it is a "sound issue" or a performance issue. Because if the restrictor fixes the sound, but reduces high-RPM cooling performance, then I'd rather NOT install it and live with the sound.

MC8jai

iTrader: (1)

thats my exact thought. I only heard it couple of times, definitely not ALL the time. If it does effect the flow of the coolant by installing the valve, I rather take the noise, since cooling issue is always a problem with rotary. My car is in storage right now, but i wonder if it only happens with colder temperature?

Mazurfer

Guess we need someone with a gauge to perform some testing and see if it does effect cooling.


Only time I've ever heard it was in somebody else's car I was helping fix and did it when you approached redline or high rpm's. We were like WTF is that????
Took me and the other guy riding with me a minute to figure it out since neither had ever heard it. Went away as you would shift to the next gear, but if yours sounded like this one..............I sure wouldn't take it!

rotarygreg

im pretty sure my car has this noise. its been slowly killing me inside. haha. But, and this is a big but, my car already has the restrictor!!! i read through the entire thread and was so pumped that this might actually get rid of this problem once and for all (ive been scratching my head for like 6 months over this damn noise). Went to work the next day, ran my vin and the computer claims my car should already have this part installed. then, not believing the computer, i go and check the car. sure enough, the restrictor is in place. so back to square one i guess.

as for any draw backs, i cant see this effecting cooling negatively at all. the restrictor goes in the line that runs to your heater core and from the looks of the restrictor it wont impede flow as much as you'd think because of the ventury effect (its clearly tapered from the picture posted in the other thread).

also, its not like your heater core does a tone of cooling when your car really needs it. i mean yeah, it will deifintly remove heat from the coolant, but it wont do much unless you have the vents and fan set to make use of the heater core. otherwise there is little/no air flowing past the heater core. and lets be honest, you're on the track in the middle of a hot summer. you dont have your heat blasting. and thats really the hottest your car is gonna get. and mine never overheated at the track. so i wouldnt worry about it.

my advice, if you have this noise and this fixes it. do it for sure. im on the verge of selling my car its so annoying!

Thumper3322

hmmm don't think I have heard this noise, on my car or anyone I have been in. Since yours is so new with warranty get it done by the shop, warranty will cover their work, and if they noise is still there after the replacement you can take it back and tell them to fix it. I wouldn't go back to Markham Mazda after that crap tho. Go to Scarb Mazda and see what they say.

Footman

iTrader: (2)

What exactly does the "heater core" function? Rotarygreg, perhaps you can chime in and educate?

rotarygreg

the heater core is like a small radiator that sits in the heater/ac box under/behind the dash. when you have the car set on heat, doors are opened/closed to direct airflow from outside, through the cowl, through the filters and blower motors, across the heater core and out through the selected vents. when you have the car set on cold, there is virtually no airflow past the heater core. its basically sitting there with hot coolant flowing through it, but theres no air running over/past it to pull heat from it.

like i said, since when its really hot out and you actually need the cars cooling system to be working 100% you dont have the heat on unless you are using your car as a sauna, this really wont be reducing the cooling capabilities.

like i said, my car has the restrictor (from the factory) and i've been to the track in the summer. your car will never get hotter than a good 30 min thrashing constantly at redline. and mine never overheated

Footman

iTrader: (2)

Oh, so the heater core is an element, where engine coolant flows through. Does it have any cooling capabilities? I know the radiator's main job is that. But this device heats up regardless whether we want heat or not in the car? Is that how all car's heating system works? It's just a valve to whether allow the air to pass over this core or not?

rx8-druggist

oooh... thanks for that quick tech lesson rotarygreg lol - I kind of get the picture now. Yeah so from the sounds of it then, the heater core heats up whether or not we want heat in the car... except if we turn ON the heat in the car then there's air passing by the heater core (or hot air if we decided to turn it on in the summer?)?

Yeah I probably wont go back there for the service... was thinking of going to avante or agincourt... but it hasn't been bugging me much now so im considering just leaving it alone =S

rotarygreg

you nailed it mate.

footman, yes typically (not every car ever, but like 95% of cars on canadian roads) this is the way it works. there are doors inside the heater box that determine if the air comes in throught he cowl or if its recirculated from whats already in the cabin. other doors that guide that air through either the heater core (for heating, duh) or evaportator core (for A/C aka cooling) or a mix of the two depending on where you have the temp dial set. then the last set of doors would guide the temp controlled air through whichever vents you have selected.

the heater core recieves hot coolant regardless of whether or not you want heat inside the cabin. im sure if you were to remove the heater core and lines from the system entirely that the coolant temps would be higher mostly by the fact that there is less volume of coolant moving through the system to pull heat from the engine. even without air flowing past the heater core and even the lines running to and from it, heat will still radiate off it and into anything around it thats cooler. still. its not like you ahve heater cores in race cars. your rad is the meat and potatoes of the cooling system.

the restrictor in question wont cause your car to overheat. i speak from experience in that (and im just point this out again to drive the point home) i have the restrictor in my car. i tracked my car several times last summer. i have never overheated or even seen the gauge come over its normal operating temperature spot. if you have this noise, and this restrictor is indeed the fix. dont hesitate to do it.

Footman

iTrader: (2)

Thanks Rotarygreg... that was very informative. I will go and install the restrictor at Scarboro Mazda.

Silvergun

OP, did you get it taken care of? Mine has the the same issue(09). I took it to the shop, but did not know what to call it. I was informed of the MIAC when I went to a meet in jan. I was wondering if you got it taken care of or left it alone.

rx8-druggist

Silvergun; I haven't had it taken care of yet (too much damn snow, been driving a Ford Exploder for a week lol) but I am planning to get it fixed soon.

I just emailed Markham Mazda asking them if someone other than the tech that spoke to me could fix the car for me without the hassle of a road test.

Hey footman, lemme know how that goes with Scarboro Mazda - if Markham Mazda is going to be a PIA, I'll just pay Scarboro a visit!

Footman

iTrader: (2)

I am at 60,600km... my next oil change is 64,000 km. I will do it at the same time when that comes up.. So it might not be for a 1.5 months.

Silvergun

Took mine in for an oil change and radio update last week. They did not do anything for the heater core... They said that it was more of a pre-09 thing... Clearly they heard the sound and knew of the issue. I decided not to get anything done at that time. It is not really an issue since I know now what it is, but the first time i heard it i almost cried, LOL!

Delmeister

If this is noise from coolant flow through the heater core, then the noise should go away if the flow is stopped, for example by pinching off one of the hoses with vice grips.

rx8-druggist

Ahh... I'm taking mine in on the 27th for an oil change and to get the restrictor put in. The dealership emailed back saying they ordered the part and have no issues installing it under warranty (i swear if they charge me for this I'm tearing up the place!!).

Footman

iTrader: (2)

rx8-druggist,

How did you bring this up with the dealership? They can't possibly do this work just cause "some internet forum thread said this is a possible fix to the problem".