Hi everybody... newbie rotary-owner, from Denmark here! Nice forum...

Just yesterday my RX-8 started to make a constant high-pitch whine, even in idle. Like the title says it doesn't change accordingly to higher RPMs. Also I noticed that the engine started running a little more "rough", one of the results was making the stick wobble a lot in idle... Yesterday I filled about ½ a liter of oil on it, as the oil lamp started to light up now and then, and the oil level was just above low. Now when I measure the oil again, I can't see how much it has on? The dip stick seems to be totally covered in oil... Maybe this is not a problem, but the sound definately is. Any ideas?

 

Congrats... whine could be a hose loose under the hood, or maybe transmission gears (auto-manual?)? or hard to tell wo/more symptoms/location of noise. What yr is yours? 04s and 05s had the oil pan sensor upgrade to stop the light coming on wo/good reason, but it was happening at 110-130 kph cruise. So again hard to tell. I think there is also a dipstick upgrade to have better markings on it, cause it was virtually impossible to read the thing. I find it easier to check before starting the car, as any oil run has down the dip stick tube and doesn't always cover the dipstick when pulling it out making it harder (impossible) to read.

Perhaps you have a good dealer to assist or go here for all TSBs (makes interesting reading trying to find your problem/solution) http://www.finishlineperformance.co...tins_index.html

 

There are two black hoses going into your intake. One comes from the MOP. I forget where the other one comes from. It's the second hose that can make a whine noise. Pinch off the hoses to verify if it's the cause.

Mine does it - though it's not a constant. Sometimes it does it, sometimes it doesn't. It should be normal, and there is a TSB about it. Something about air going through a jet air nozzel or something.

 

Thank you both for extremely quick replies! Nice...

Manual transmission, automatic hasn't really caught on around here...

The local Mazda dealer said the same, probably a hose, but they couldn't fix it within the next 14 days. I guess I can do a lot fun stuff with the money I save on gas (just under 2$ per liter now!), but I don't want to be rotor-less for two weeks!

The whine seems to be coming from the left side of the engine, around the rotors them self. You think I can still run the RX-8 (no high RPMs though) without damaging the engine?

Edit: Can't get the link to work.

 

After yesterdays oil change at my local mazda dealearship the noise started, a very high pitched noise. Ill check that hose that was mentioned before. And post back the results.

I am starting to hate my dealerships service center.. who ever changed my oil this time was a complete *** cuz they bent my dipstick, not just the tip like it says in the tsb but the wholething was bent. Seems like the tech was lazy and didn't want to bend over to put it in strait. Also I asked them to recheack my front right brake because its still squealing even after they "fixed it". They then slaped me with a brake inspection bill and said that i needed to replace my rotor and pad. They said it was fine when my car was still under warrenty 3000 miles ago. I say f*** them and im keeping the flashlight they left in my engine compartment!

 

Davs!

It might sound like a strange suggestion, but one or more of your spark plugs may have backed out a bit. This has happened to me more than once.
It is likely that it is a disconnected hose on the intake bellows, though.

 

Well, its a vent for the oil pump distribution nozzles. I'd think that it is designed to ensure that there is always the same relative pressure behind the oil feed.
Since it is on the intake side of the rotor housing, it will mostly see vacuum (unless you are FI), so you shouldn't see oil coming out that way.
Really, I'd plumb that line to a vacuum feed behind the TB with a check valve - especially if you are FI - because there is the possibility of there being pressure instead of vacuum being generated at the nozzle from resonance effects (or boost, if so equipped).

 

Yes, both of the hoses that are under vacuum (oil injection and air jet mix) whistle.

Your compression numbers are low - below the shop manual minimum of 6.9 kgf/cm2, but they are within the variation limit of 1.5 from chamber to chamber and 1.0 from rotor to rotor.

Just so you know, the translation of that compression test to more "common" numbers are 91, 88 and 90 PSI for the front and 88, 85 and 98 for the rear.
8.5 or 120 PSI are considered a good number. I have yet to run into one "in the wild", as it were, that actually reads that high. Most "good" engines seem to peak around 105 to 110 PSI. A brand new motor should show 125+ PSI!

Since you have a CEL (which is from the e-shaft sensor, I'd bet) and the numbers are not consistent with most typical engine failures, I'd say the actual test was botched to some degree.

 

If you do attempt your own compression test, get a really good gauge and a video camera (position the camera in front of the gauge while it is held open and watch it at your own leisure, instead of having to try to read it as the measurements speed by).
Otherwise, you will be just checking the highest number as the puses will average themselves.
Most compression gauges are too slow to show the peak for the short duration that it exists.

I suggest a leak-down test as a more accurate measurement.

 

I'm going to try to search for reseting the e-shaft sensor but if you can post a link to how to perform that I would greatly appreciate it.

 

Turn the key to "ON" without starting the motor.
Start stepping on the brake pedal as fast as you can, repeatedly, until the oil pressure gauge sweeps.
Done.

 

Okay I did that recently after changing out my Pulley for the Agency Power. Didn't realize that was something that was being reset. Should have figured...thanks!

 

A little news from Sweden...

I just had the generator replaced as the local dealership was pretty sure that would fix my whine-problems. It didn't though

Out of the blue, I tried resetting the e-shaft sensor and that actually removed some of the vibrations felt through the stick shift, not the whine it self though. I then proceeded to give the engine a "good talking to" for half an hour or so. When I pulled in to the garage the whine was pretty loud.

I found the hose that's making this noise - check the picture. What's my problem? Compression? Leaks? Any help is very welcome...

@MM: Davs?

 

Ahh. That hose is supposed to whine. Its normal.
That is the air intake for the jet-air mixing feed.

 

Really? But is it supposed to be so loud that you can scare away birds and small children with it? I never noticed it before...

How come you know "davs"?

 

Fordi jeg fik mig ungdom i Danmark!

 

Sorry about that. MM just explained in danish that he had a very sad youth...

 

Heh! We always told foreigners that there is an easy way to tell a Swede from a Dane on the streets of Copenhagen: Look for the drunks, because they are the Swedes!

 

IT will throw a CEL on start-up. That is one of the things the GReddy O2 sensor dongle defeats.
You could build a circuit that sends a full-lean signal to the PCM on the WBO2S input whenever the air pump signal is activated.

 

You can get an AutoSport harness so you don't have to hack your OEM harness up.
http://www.autosportwiring.com/mazda.htm

The diode trick on the blue e-man will do the trick and you can drive the dongle with it just fine. However, getting the dongle will be a trick because GReddy doesn't sell it alone.

 

Coil interface - diodes protect the coils from high "off" current.

 

The dongle achieves the same result, without the CEL.

 

Well, since I'm danish I already knew that!