JJ01769

I finally got 580 miles today so I thought I would take it up to 6k during one shift to try it out. Just as I hit 6k, there is this grinding sound comming from the engine. It sounds similar to when you grind the transmisson but not as intense. I dont think this is very normal.

JNUT8

hummm it does make a little wierd noise due the the rotars (almost like ball berings hitting or something) but i would necessarily describe it as a grind. Listen to it closely if its the engine its probably normal if its the tranny you might need to get it fixed.

JJ01769

It could be, Im not sure what it is. It only comes up at 6k rpms, I havent taken it up past that so I dont know about it. It kind of sounds like a ringing sound almost.

Charles R. Hill

iTrader: (7)

This question has come up in the past and it is (only) my opinion that it may be the ring gears in the rotors and E-shaft making that whining noise. Since they are straight-cut they make noise much like a set of camshaft gears when used on a V-8 engine. If you want to hear some really strange noises, rev the engine to about 9K (right before the beep-tone chimes), hold it there for a minute, and take a listen. Of course, wait until you break the engine in fully before you do this. Don't worry, I 'm not trying to get you to blow your engine. I did this to trace a strange sound I was hearing under nitrous boost at 9K. Those strange noises at 9K are doubled with nitrous use.

Charles

JJ01769

Ah thanks alot for the info. It was the first time I pushed it up that high so I didnt know what exactly it was. Just wanted to make sure something wasn't terribly wrong.

zoom44

<<< have you read the SDAIS thread yet?

Charles R. Hill

iTrader: (7)

Hey Zoom, I have read the S-DAIS thread but I don't understand why that would have anything to do with the sound(s) described above. Do you think that the intake system, itself, is making all that racket? I also have heard a similar sound at lower rpm's under moderate load. Either way, the thread you mention is a real good one.

Charles

houstonrx8er

iTrader: (8)

I am having the same proplem (if it is a problem) in the high rpm range its a ringing noise right before the beep tone! Mazda doesnt care unless it is broke. So I will wait till 35,000 miles then re think the situation.

Austin

Charles R. Hill

iTrader: (7)

When I am using the nitrous, all those sounds described are amplified. At first, they had me concerned but I later surmised that the incoming air charge was making all that noise and, since the rotary has no valves, there is not much muting or sound dampening going on. I haven't had any problems, otherwise.

Charles

Ully

First of all, excuse me for my bad english.

I have the same problem. Sometimes (not always) over 6k rpm the engine sounds very different from usual and I hear a grinding sound too.
Also, the engine seems it doesn't rev up fast as usual.
I think it's not normal....

houstonrx8er

iTrader: (8)

That is the same thing I have happening. Some times the car has more get up and go than other times. And it is relative to the noise the engine makes. Strange, is their anyone that explain it.

Charles R. Hill

iTrader: (7)

Not to be too elementary, but how's the fuel quality you guys are using? Many of us are now using the Shell V-Power Super. Also, has the problem been getting gradually worse? If so, there is someone else around here who has had their cat clog up on them. The symptom was inability to rev over 6K due to restricted airflow. Not to alarm you both but maybe you're in the early stages of just such a problem.

Charles

Ully

Some members of the italian forum have experienced the same problem, and one of them has solved this troubleshot changing the spark plugs. Probably, if spark plugs are dirties, there is a bad fuel-air combustion, and this causes the strange engine sound and less get up of the car.
Dirties spark plugs can also damage the cat and a damaged cat causes similar problems (metallic sound, engine don't rev up well).

Charles R. Hill

iTrader: (7)

Early recipients of their 8's reported fouled plugs as being a major warranty issue and the dealers replaced them. I suppose this is an issue worth following. I would suggest you take your car in and tell the dealer to replace the plugs so they don't have to replace the cat later on. Another tip; try not to spend too much time driving around at low rpm's like 3,000 or less. the plugs will get fouled. Every now and then give the engine a good 9,000 rpm pull to keep things healthy.

Charles

Ully

Maybe...

Ully

Thanks very much for the tips and informations.

houstonrx8er

iTrader: (8)

I run Shell 93octane. I will try the spark plugs, is there any particular brand reccomended? Also I drive the hell out of my car, I got it in march and it has 18.7K miles (mostly hard driving)!!