fyrstormer

Weird noises aside, I really do love the sound of this engine.

EC8

When you had MIAC, was there a slight loss of power or hesitation when you heard it? I read through some other posts and almost all talk about the sound. My '09 makes this noise in 2nd gear at around 7800+, very smooth acceleration up to then, and then at the same time the noise starts the acceleration slows a little, feel a little hesitation. Still winds out and redlines quickly, but definitely a slight hesitation that you feel when the MIAC starts. Is that normal and will be fixed by the coolant restrictor valve? Use only good gas, 700 miles on the car, sport 6spd '09. Thanks.

Old Rotor

Are you using prem-gas? Please give us the history on your car.

EC8

Only 91 or 93 octane gas. Did a little more "research" driving the car around last nite and accelerating slowly or at least slower up to 9000rpm. The sound definitely starts around 6200rpm and after listening to the youtube video of MIAC, I definitely attribute the sound to that, and will get the coolant restrictor valve in the near future. Under mild acceleration there is no hesitation around 8k. Under WOT I didn't perceive the sound until closer to 8k but now am pretty sure it starts earlier, just couldn't hear it quick enough or link it to the right rpm. Under WOT I definitely get a slight hesitation/hiccup in power right around 8k. Nothing major and it still hits 9k very quickly after that, just going from 7900 - 8100 is not as smooth as 1k-8k or 8100-9k. Speaking with Lane over PM it sounds like he notices the same slight hesitation/power burp right around 8k as well, but only under full throttle.
Summary: My sound starts earlier than I thought, most likely coolant restrictor valve, but both '09s (mine and Lane's) seem to exhibit a slight power hiccup under full acceleration at 8k

Old Rotor

You don't sound like you have the MIAC detonation problem. The MIAC is loud followed by a loss of power and is very bad on the engine. It sounds like you might have the water restriction sound that some complain about. This restriction does not cause the hesitation you notice. Some on here have got Mazda to fix this water restriction sound.

EC8

Sounds like several people have had this issue, and several have had it fixed by Mazda with the installation of a "coolant restrictor valve". Could someone please do a little more digging and check their receipt or even call the dealer that fixed their car and get a Part # of what was installed?

My dealer is willing to install the part/make the fix but can't find the part number or find a listing for the restrictor valve and has found nothing to order. As he put it, help me help him please.

shallowater

my car developed this exact problem since last week, time to call mazda dealer...again.

one question though, why there is no such problem before and suddenly it just came out of no where? if it is caused by too much coolant flow at high RPM, does it mean there is something wrong with the coolant (reservoir/sensor etc.) as well (since the rattle did not happen before)?

Lane03

Updated first post with P/N...

Mazurfer

Lane..............the only thing I can find under that part number "F10061E09" is

ORIFICE, HEATER HOSE DIESEL

You confident about that number? Guess it could've changed or maybe this is something that secret and not widley known???????

EC8

Thanks Lane,

Got a call into my local dealer to check on that P/N. Hopefully he'll come up with the same restrictor valve that was installed on your car. I'll update when I hear back from them.
Thanks again for the extra legwork

Lane03

That's the number I was given over the phone. I will be getting my oil changed next month, at which I will try to get a print out of what was done. If that number is for a hose, perhaps they just replace the coolant hose with a smaller ID hose to restrict the coolant flow???

Mazurfer

That's what I'm thinking. The only thing I could find under that number was for like an 02 Mazda 6 and it did look like a small hose coupler actually. I'll see if I can find the picture of what I came up with.

Here it is:

Top lefthand dashed area.................F10061e09

http://www.avtopartmaster.com/ru/?ac...E9%20%E3%EE%E4

EC8

Talking with Trubach over PM, he confirmed this and also gave me a Mazda Techline Case number:

Techline Case # 613795 (I think thats a Mazda thing telling the techs what to do)
The part is F100-61-E09 Orifice, Heater Hose

Spoke with my dealer this morning and he said they can look up the case number and will help them with the fix.

Thanks Lane and Trubach/Gary

UPDATE: My dealer can't open up another dealer's case number, but has ordered the part anyway. Said he could order it 2 different ways, one with the hose, and just the orifice, he has ordered just the orifice because based on the replies above, that should be the only part needed.

Lane03

This really should be a sticky or in the FAQ...

Mazurfer

Once proven on a few more cars....then I would agree.

EC8

Brought my '09 into the dealer today to have the "orifice heater hose" installed that he ordered last week. This fixed my problem as well! Thanks for those supplying the part numbers.

MikeBusch2

Anyone have pictures of where this orifice goes? I'd like to order this part and install myself if at all possible.

Thanks.

Suspension

I hear the coolant cavitation noise (what you guys call MIAC) in my '09 R3 at higher RPMs. I brought it up to the service manager and he said "That's normal." BS. Did this ever happen on '04-08' RX-8s? Is there a TSB?

shallowater

there is no TSB.

i brought the car to dealer today and described the problem, i even printed out this thread to show him. no go. dealership says that is normal since there is no TSB. also said that they cannot do it just because some internet forum (that is here) posts this as a problem...oh well. spent 10 mins arguing and told him it is just a simple fix. no use, the dealership won't budge...

it is thanksgiving eve and i don't have time to waste there, asked him to document the problem so that it is in the record that i brought this up...maybe i will call mazda later...is this a known problem to mazda? i have had enough BS from the dealer already.

ASH8

Now I can't speak for your LHD Cars, but, it appears Mazda did not put these "orifice's" in ANY 05-2010 RX-8's..

I just checked the part number in my RHD Parts Catalog and this orifice was Originally Used in the Series 1 RX-8, UP TO December 1st, 2004 production....

Mazda then Stopped Installing them from Dec 1st 2004.

Here is a Parts pic of exactly where it goes (in RHD S1), it is actually in the engine bay by the Thermostat outlet that supplies coolant to your Heater.

ASH8

My EPC (RHD) says it is used in S1 RX-8, FD RX-7, 07 Mazda 2 Diesel, 02-07 Mazda 6 Diesel...in the heater hose areas.

EC8

I'm not sure exactly how it was done, but this is the write-up on my service invoice:
R&R battery, drain coolant at block to gain access, removed smaller size thermostat hose to firewall and install orifice in hose, replaced coolant.

Probably doesn't help a ton, but that's what I got.

This sounds definitely like a dealer problem for "Suspension" and "Shallowater". My dealer had never heard of this before and I told him my car was having this problem, here's a printout of what I found on the internet, the RX8 forum is actually linked through MyMazda so at least there's some connection. He couldn't find the original "restrictor" part and then I called him with the part number. They were extremely accommodating and never paused about whether to fix it or not. Other's have suggested you/they drive other '09s on the lot and see if they hear the problem, if not then it's obviously not normal. And just because there is no TSB is no reason why it's not a problem... Good luck with them, or take it to another dealer. I've heard others contacting Mazda NA and getting resolution that way. Good luck

ASH8

Yep, your service Invoice is correct, and the "orifice" is installed inside the Heater Hose that supplies Coolant to and inside under dash Heater Core (Radiator), see parts pic above (red) that is the small orifice that your dealer fitted.
The Hose "end" in question slides onto the metal Outlet on the Thermostat Housing near the bulk head or firewall.

As I said the Initial 30,000 03-04 RX-8's had them factory installed, AFTER Dec 1st 2004, they ceased to put the orifice in ANY RX-8's.

At this stage it is not a TSB because Mazda are only rectifying cars in which owners complain about....

ASH8

Yes, I would call MNAO for sure...

There is NO Difference to the Heater Cores or Hoses/Pipes between Series 1&2 RX-8's, or the bits that matter.

This is another one of those "sneaky" repair jobs that Mazda Distribution don't tell the dealers (via TSB) unless the Dealer Calls Mazda NAO, or they get a customer complaint.

There have been many of these done in the US, so your dealer needs to BONE UP or GET OUT!

Mazurfer

Yeah, I checked all my diagram files and parts lists and don't see it anywhere. Originally when that part was talked about in this thread, I googled it and the only place I found it was on some Euro site and said it was for a Mazda6.
This is good to know for those that really suffer from MIAC as it appears as if this is going to cure it.
I can't see any real long term effects can you?