Adamrotor

Well, I wen t to the dealer yesterday and I told them about the engine noise. It sound like a whisle of some sourt. So one of the mechanics looked at the car and they have showed me the possible problem that might be 100% for sure as far as I think so. Well the problem is, the PCV hose, or nosle thing has a possible crack or slice in it, causing the whisle. ANybody had this experience.

doubleohsmurf

PCV=Positive Crankcase Ventilation...13B MSP doesnt have a crankcase to ventilate, unless its for the eccentric shaft chamber.

But if you are talking about the intake vacuum system yes I can see that, but I haven't heard or known anyone to talk about that problem. Probably just a random mishap, but hey you might notice better performance or MPG because of that fix!

TwoZooms

Thanks for the info, Adamrotor. I've been trying to figure this noise out for a while now. Can you give me some coordinates under the hood so I can zero in on it? My service department couldn't find it.

Adamrotor

Well, It is the hoseing that sits by the sway bar. going down, the mechanic said its the PCV hose or it might be the nosle connecting it. Hmmm... its the hose connecting to the intake system, its sort of hard to explain but its very visible.

mikeb

can you post a pic

I have that noise

TwoZooms

I'll plan to do a little digging around under the hood this weekend, Adamrotor. Thanks again for your post.

TwoZooms

Yes, a picture would be extremely useful! To reiterate from a previous post, I have not noticed any decline in fuel economy or performance. Just that strange noise.

mikeb

yes I have k&n

Adamrotor

This is not my car just in case your wondering.

sohcpunk

does this noise only come on when you first start your car from cold?

TwoZooms

Thanks for the photo! In my car, I hear the noise only after the engine has warmed up. Other noises obscure the sound when I'm moving. I have noticed that the pitch of the noise doesn't seem to change when I blip the throttle.

D MENAC 7

I have he K&N and have a digital recording of it that I might make into a sound clip. I also have the noise, it sounds sort of like a sewing machine but not as harsh. It's kind of an interesting sound to me, like that of some well engeneered machine. However, if it is a hose off or something else, I need to see what it is too.

shelleys_man_06

I've had experiences with the PCV in non-rotary cars. I have never heard of a car making noises. Like D MENAC 7 said, it could be something else. Last time I had a PCV hose valve disconnected (different car), the car wouldn't start.

pmacwill

I have that noise, its called a rotary engine? no? maybe I don't have a noise

Adamrotor

Well, when I was at the mechanics the hose on the photo he held down and its stopped makeing the noise, every time he touched it changed .

dcfc3s

Rotaries don't have a crankcase per se, but there is a PCV system. It's mainly a vent for the oil pan - with the oil pump running and expansion due to heat, the air in the top of the oil pan has to be allowed to vent, or the system will pressurize and you'll get all kinds of weirdness.

By emissions law, a car has to burn any emissions, including evaporative, so the "crankcase" is vented through a PCV valve into the intake. Any gasses from the oil pan are burned, and the "crankcase" is allowed to breathe properly.

The PCV system can be open-air vented and the car will run just fine, but the nipple or whatever where the PCV system routes into the intake would have to be plugged - with it open, it's a vacuum leak, which makes a car with an airflow meter run like crap.

A crack or small leak in the hoses to and from the PCV valve could definitely cause a whistling air leak. There may be a TSB in the future on this one if enough people have it. Likely a VERY easy fix - new hose, clamp, something.

Dale

D MENAC 7

When I changed my stock CAI for a K&N, there was one main hose going to the oil fill tube neck, I assumed that is for ventilation of the oil chamber or whatever it is called. However, I noted an additional two tubes that I did not see where they go to. Where do these tubes lead to and what do they do? They are almost as large as the first one I identified, they are not small by any means.

TwoZooms

This makes sense to me for at least two reasons. First, the noise does indeed seem to be coming from that part of the engine, and second, I'm only hearing the noise when the engine is thoroughly warmed up. An oil pan vent would also explain why the noise doesn't seem to change in pitch (at lesat not noticeably) when I blip the throttle. I suppose a relatively small leak (which would tend to produce a relatively high pitched noise) would trip up the airflow meter, but only in a relatively minor way. Not to belabor the point, but I can't say I've noticed any performance or mpg issues; that said, a 1-2% change likely wouldn't be noticable.

rotarygod

It is true that we don't technically have a crankcase to ventilate. The PCV valve on the rotary covers the air inside the motor in the oiling system. If you could blow into the pcv valve hole, it would go straight through the engine to the oil pan. On some high powered turbo RX-7's, oil sometimes gets blown out this hole which is why some guys run a catch can.

LambertRX8

I too have heard the whistling noise as of late after start-up. Haven't checked for it after running for awhile, forget to.
I have also had and oil leak the past few weeks so took it to the shop. He said it was coming from the "oil meter pump". There was lots of oil around the area and was burning on the exhaust during driving causing fowl oil smell, that's what got me concerned.
They tell me it is 1200.00 for the new pump plus labour. Car has 114,000 miles on it so warranty is expired.
Any thoughts or ideas?

tmak26b

EGR you mean?

LambertRX8

Not sure what you mean by EGR?

Old Rotor

disable the OMP and do your own pre-mix and save the $$$$.

Rick

The smog pump, or whatever mazda calls it these days, runs for about 30-45 seconds after a cold start. If your pump is making a "loud" noise you may want to have it replaced

aerospacediver

Did anyone else have a seizure and fall backwards out of their desk chair after reading this sentence?