Wierd Engine Noise!!
 

Hello,

I have a very wierd engine noise which I cant seem to figure out.

First off, the car specs are: 2005 Rx8 AT, 107500km, plugs and coils changed at 96000km, no engine or performance mods. A few visual mods. Both the front and rear O2 sensor and CAT were changed 3 weeks ago.

The noise I am hearing sounds like a chirping noise coming from the engine a low speeds (under 30-40km/hr). When I reach higher speeds than that, it begins to sounds like something "flapping" coming from the engine area. The faster is go, the faster the flapping becomes. Also, when this happens there is a very noticable loss or power and the engine seems to run and idle very roughly.

It seems to only happen after I have been driving for some time. after about 20 minutes or so and continues for the duration of the drive. The next morning it will be fine once you first turn it on but then will start again.

Any ideas?

*Edit* The sound only happens when you press the accelerator pedal. As soon as you let go of the gas, the noise stops.

I have the same exact issue with mine an I can't figure it out either. I also have a 2005 A/T

have your compression checked guys...

Is it something I can do myself? what do I need to do it?

Doing it is not a big deal, you need a compression tester. Unfortunately the one you can by at the next shop around the corner isn't working for us because it needs to do 3 measurements at a time.
Your certified RX-8 shop got a special tester for the rotary, the easiest is to go there and ask for having it checked. should only take half an hour or so. If you got a weak heart, I would advise you to have a seat outside, read a nice magazine and wait for the result.

Greetz

bad compression calls for a new engine right?

dose this help at all last Sunday i did my oil change I lowered the car started it up no problem took it for a spin 2-5 miles came home parked the car for 3hrs went to start up and nothing when I looked up my check engine light flashed 3 times I waited a min and tried again it started up no other issue other than the chirp

Hmm...that sound interesting. I just had a solid CEL go on and the mechanic tells me that I have low compression but they will need it all day to pinpoint the exact cause.

I second that statement, doesn't low compression require a new engine sometimes?

Keep me posted on what happens so I have more info on this issue. Right know I have a few of the locals helping me out since I'm gonna have to wait till payday to go get the compression tested at the dealer next week

not sometimes, in any case low compression means your engine is busted.

Edit: Btw welcome to the club ;) got mine changed last weekend...

@Darkpoison: maybe Azrael has something to do with the possible death of your engine? ;)

Well, heres the latest update. The dealer is positive that the low compression is due to the oil metering pump. However, I am at 107000km so I am 7000km over the powertrain warranty.

The dealership has talked with the regional manager and Mazda Canada and have offered to split the cost of replacing the oil metering pump 3 ways.

After parts and labour it would come out to about $500 each person.

Do you guys think that it will solve my low compression?
Also, will the noise I explained be solved if the low compression is fixed?

Another question:

Is there any damage done to the engine if you drive with low compression?

It will help the compression a little bit. But the bottom line if the OMP failed is you have a junk engine now. Worn out before it's time. I would complain to Mazda about the fact that the OMP not working has caused your engine to wear out before it's time. So now due to the OMP failing your going to have to buy a new engine if the compression does not come back to factory specs. Not a good deal at all.

Low compression is not going to hurt the engine physically. The damage has already been done. What caused the compression to decrease is the factor here. The OMP failing.

In that case I would slow down a little bit. Sounds like the dealer wants to make double business. The OMP is not very likely to fail, if it did, the engine is messed up anyways. But there are several other reasons which could cause the engine to break down and lose compression. Before buying a new OMP in your case I would double-check if the old one is the root cause by having it checked and always demand a test report. In case of the OPM here's the way to go:

Metering Oil Pump Control Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Verify that DTC P1686, P1687 or P1688 are not displayed.

• If DTC P1686, P1687 or P1688 are displayed, perform the DTC inspection. (See DTC TABLE.)

3. Turn the ignition switch to the ON position.

4. Access the MOP_POS and MOP_SW PIDs.

5. Move the metering oil pump motor using the MOP_POS PID and verify that the MOP_SW PID changes from on to off when the MOP_POS PID is in the range of 53 steps or over.

• If MOP_SW PID does not change, proceed to the next step.
• If MOP_SW PID changes, inspect the following:

– Oil pipe (leakage or cracks at metering oil pump-oil nozzle)
– Oil nozzle (clogging)
– Vacuum hose (clogging, leakage or poor connection at intake manifold-oil nozzle)

6. Inspect the following:

• Metering oil pump motor
• Metering oil pump switch

– If there is a malfunction, replace the metering oil pump.

If it really was the OMP, wouldn't my oil level stay the same? As opposed to going down?

*bump*

The engine has an 8yr/100,000 mile warranty in the US. I would ask the dealer to print out your Mazda Extended Rotary Core Warranty and make sure they are not jerking you around. Also, don't let the dealer get away with replacing the OMP and giving you your car back. Call Mazda's 1-800 number and fight the case that if the OMP went bad then your engine did not get lubricated properly causing low compression and ultimately destroying your engine. Good Luck.