xero256

iTrader: (1)

I tried searching but I suppose that feature does not like me today - it normally works...

Either way, the engine is misfiring to the best of my knowledge. I hear a lightweight clicking sound from the exhaust when I'm on the throttle or when I get off the throttle and the car is in gear and moving (engine braking). It happens at all RPMs when the engine has a load.

It's never as easy as that so here's the catch - This never happens when the engine is cold. I start her and everything is normal. I don't like to rev her or anything when she's cold so I haven't tested above 4k but no clicking at all. Even when the motor is under a load (in gear and moving forward). As she warms up it starts and slowly gets a bit louder.

During the summer this started and was quite annoying. It has gotten quieter as the weather has cooled indicating to me that it has something to do with one of the sensors on the intake. Am I thinking in the right direction or what?

I have an aftermarket exhaust - Racing Beat, no cat, stainless from the ports back. You can hear the clicking loudest around the headers and it seems to hit around the same time as the typical exhaust sounds from the back. An exhaust leak would occur at idle and you should hear it right? Or would a minor leak do this and get louder as the crack expands or something?

I'm trying to get a friend to help get a recording of it. I'll post later if I can get this together.

Rotaries are simple motors but for whatever reason Mazda has decided to put the most complex supporting structure around the damned thing. I've got a '91. She's got some weird stuff in the intake and sensors out the yingyang. If I can figure out which one is dead or dying, that would be awesome. I'd like to avoid going to a dealership as the only one within 100 miles that is willing to look at my car also loves to loosen oilpan bolts!

Puck

iTrader: (1)

If it were me, I would start by checking all bolts on the exhaust, especially at the header. Never know. It is usually opposite for an exhaust leak though... usually you hear it when cold, and it goes away when warmed up.

xero256

iTrader: (1)

I'll have to check the exhaust bolts and such. I thought that the gap would widen as the exhaust heats up.

I've been trying not to drive her too much as I'm afraid that the car is running too lean and slowly obliterating my apex/side seals. I'm not up for a rebuild atm... I don't know many that would be. Anyone have an extra $2000 sitting around with nothing to do? Granted, if I do that, I might as well have some fun and pick up an extra motor and have a custom eccentric shaft made and ECU and double the rotor count.

I also forgot to mention, that the injectors were recently cleaned. The fuel filter was also recently replaced - OEM I believe. Intake filter is new.
*scratches head*
I think that's it.

K-Tune

iTrader: (26)

you don't have a misfire. a misfire will sap a lot of power when it is happening.

you are either detonating or have an exhaust leak.

xero256

iTrader: (1)

Detonation.... *searches for information on the matter*
Ha! The search function worked for me!

Based on what I've read, the detonation thing might not be it. I made use of my timing light when this first happened and the timing is perfect.

From what I've read, the detonation thing is violent - but nothing rattles. The motor runs quite smooth actually. I don't know if I have any real power loss either. It's just the odd sound from the exhaust that is throwing me off. It certainly doesn't sound healthy.

MJAsony2305

Maybe theres just somthing rattling around in your exhaust. On my 92 celica when the engine is under load the exhaust hanger rattles a bit but once up to speed and cruising its gone

xero256

iTrader: (1)

The rattle theory seems to fit as the sound is intermittent. It could be that tension is taken off of something as the motor rocks right and left. I did, however get it to stop at one point. Driving to work tonight, I accelerated from 80 to 90mph. No noise. While cruising at 90 for a short time the sound wasn't there at all. Motor was running smooth the whole time. When I slowed back down to 70, the sound came right back.

A co-worker of mine has his mic with him tonight so we can record the sound.

I also noticed something else, normally the center console thing where the shifter is and such is warm/hot. Today it was cool if not cold, which is odd for my car. I've got a Racing Beat exhaust system. It's stainless from the ports on back. No cat. Loud as all get out. Maybe it was cold enough outside to keep it all cool? During the winter it's normally warm and summer is really hot.

xero256

iTrader: (1)

Got the sound bites... I've clipped out the nonsense so I can send just the important stuff. PM me with your email address if you would like to hear it as I have no way of hosting the files at the moment.

xero256

iTrader: (1)

PM's replied and email sent to those who requested a listen. The recording isn't as clear as I'd like for it to be. We'll be trying again later with a different Mic.

Handful

iTrader: (1)

a Small exhaust leak will sound like a ticking sound. Start your car and put your car around your exhaust and feel for any leaks. Don't do this when the car is too hot or you might get burnt.