Woody77

Had the car a week, and I've noticed that when it's idling when fully warmed up (at a light, or before I shut it down in the garage, etc), it's making a soft "puff" sound mixed into the purr of the idle. If it's idling at about 800rpm, it will go from "purr" to "purgrgrg", "puff", and then purrr again.

(explaining sounds over 'net sucks)

Anyway, it sounds like like I'm used to a misfire sounding in a non-rotary...

And I've gone and shut everything down (A/C/defrost, stereo, etc.) to listen and make sure I'm hearing/feeling it correctly.

coils? Car's going to go in to the dealer since it's so new, of course.

paimon.soror

iTrader: (15)

Might want to grab a sound clip. Pops and puts are pretty normal with this car.

Woody77

Yeah, I just found a thread talking about "thumping" during idle on a cold start. Another applicable description. I'll listen to the audio clip on that thread after work.

Woody77

And having listened to the clip, the "thumping" at about 2 minutes in is very similar to what I'm hearing (I've not been out of the car). I'll take a listen tonight.

Here's the links to the thread and clip I'm referring to:

https://www.rx8club.com/showthread.p...98#post3443098
http://www.youtube.com/watch?v=oQxY_cHfSCI

jasonrxeight

its telling you time to open her up hit some red lines.
mine does that if I been granny driving.

cold engine thump is normal because the seals dont seal properly when cold.

paimon.soror

iTrader: (15)

Yup completely normal. Its even normal for a somewhat rough idle like the one you hear in your video along with the pops and thumps. It is more pronounced in the cold though, once spring time comes around it wont be so pronounced.

shaunv74

As long as you're not granny shifting...not double clutching...

jasonrxeight

lol, I usually open her up on daily basis. religiously following red line a day keep the carbon away.

Woody77

As do I. But then, that's been <10 days so far. But each car usually gets a WOT blast up a certain freeway on-ramp in the mornings (after about 30 minutes of driving).

One concern I have is that I live in the mtns. It's a 700' drop in about 1/2 mile to get down my hill to the main road, and then 2 miles of mostly flat 45-55mph curves, and then a 1000' climb over 5-6 miles (at 55mph most of the time).

But that cold engine, high-vacuum descent has me curious about it's effects on a rotary engine. All my other vehicles seem to pick up carbon faster than I'd expect them to. (Dodge Ram V8, 350Z, WRX), my guess has always been sucking oil past the rings on a cold engine. A bit of a different situation with a rotary, I'm guessing.

Also, that means it gets put away after a steep hill climb, 2nd gear and moderate throttle for most of it, and then dropping into 1st for the last set of switchbacks as you approach the house.

jasonrxeight

well rotaries have seperated oil pans so should not be a problem
also pressure shouldnt affect oil passing piston rings, engines have breather hoses so its impossible for pressure to build up
as for 350z, those VQ35DE's burn oil so dont worry.

PeteInLongBeach

I don't know where this opinion comes from. Unless very cold, my 2009 never pops, putts, thumps, or anything else other than a normal idle. Smooth as silk.

PeteInLongBeach

That has been my experience also, with my 2009. Otherwise, it never misfires at idle.

paimon.soror

iTrader: (15)

Right, I should have been more clear, it will make pops and whatnot as the engine warms up to optimal, but then after that it shouldn't really pop unless you are redlining.

PeteInLongBeach

Mine never does this unless it's less than 40 F ambient temperature and the engine is stone cold - even then it is very minimal. Otherwise, no pops, thumps, misses, whatnots....

Woody77

And mine doesn't do that at all when cold, just when it's fully warmed up and left to idle for a minute or so. The video above is from someone else, it's an example of what I'm hearing.

I need to make a clip of my car, still.

2010rx8

Mine just started doing that a few days ago. It sounds exactly the same. The check engine light came on and sure enough it is a misfire. Called my rotary guy and he said mazda was having a lot of trouble with the 09-10 rx8's misfiring. mazda is dicking me around before they do any work to it. ugh.

jasonrxeight

have code pulled. mine never misses.

shaunv74

The put put idle is normal with the weak stock ignition. The solution is to install the BHR ignition.

I swapped in brand new stock coils and wires for my Mazsport ignition and went from a smooth idle to the good ole put put pop idle. :/

It's normal but not correct. BHR is the only way to fix it.

Woody77

Once warm, about 10 seconds after I come to a stop, it starts missing. The longer it sits idling, the more often it does it... :/ I'm scheduled to go in for maint on 2/14 anyway, so I'll chat with the service guys then. See what they have to say.

If the only solution really is the BHR ignition, so be it. If it's just an annoyance when idling, I can wait. If it's fouled plugs or similar, that's a different story.

The top end of the power band feels fine, though. I get a nice even pull all the way to redline, without the slacking off of torque that I get on my WRX as it gets near redline.

ASH8

A fluff or a pop or puff or fart when engine is warming up and at close to idle is TOTALLY normal..

With over 20K Miles mine idles as smooth as silk when HOT at idle with OEM Coils, my car starts within half a second or less also.

More like your plugs could be slightly bunged up.

As for your Rotary Guy saying Mazda are having a lot of trouble with 09-10's misfiring, I call a load of BS, two dealers I know well including a contact at Mazda Australia (owned by MMC Japan) know of no issue.

2010rx8

I went to my mechanic to pull the code to see exactly what it was and it says "engine cylinder 2 misfire". Check engine light is still on. Going into mazda tomorrow. Should I just buy a BHR or mazda sport ingition and coils?

I have 6k on the car by the way. My plugs are burned up?

jasonrxeight

just drove my rx last night before snow storms hits here. it started fine even had not been started for 2 months I think. drove fine. love to rev the engine. summer tires in cold weather is a bit scary tho. on ramp hit the power band, tail started to kick out in a curve. thank god I had the VDC on.

ASH8

Told you it would be OK without Oiling Her UP.....the car that is!

Stability Control can be a godsend

ASH8

You should not be getting ANY misfire with a new car of this age...

I would be checking to see that Spark Plug leads are on correctly, or you could have a bad spark plug, if you can't do that then let the Dealer look at it...Your car still has warranty.

If you believe a coil "upgrade" is going to do anything, apart from spending money, go for it, but again you are under warranty, etc, etc, etc, etc.

I have not heard of any Coil Failures in S2's...yet

Most who have upgraded have also changed their Spark Plugs, so naturally they will see/feel a difference in their *** dyno, you spend hundreds of dollars so it must be good.

Woody77

I've been out of town, so unable to do anything about this until now.

Tonight after driving home (>20 miles, >30 minutes, 2-lane mountain twisties), I recorded this video in the driveway. The mic on my iPhone isn't the greatest, and the dull "thumps" coming out of the exhaust sound more like a cough. If you think you're hearing pinging like cooling exhaust, those are times when it was thumping. As I've said before, it only seems to be an idle issue, and even the extra load/rpms of the A/C compressor kicking on will stabilize things, although it stumbles pretty hard when the A/C compressor kicks on (it does so at 34/35 seconds into the video).

http://www.youtube.com/watch?v=CheVAKQVuVM

My plan is to pop the cover off this weekend, double-check everything visually, and chat with the dealer about it on the 15th (scheduled maintenance with them). They'll have the car anyway, so they can look at it then.