Somewhat in reference to a previous post:
https://www.rx8club.com/rx-8-discussion-3/so-4-years-45-000-miles-final-impressions-125900/

so there I was at Mazda service not too long ago getting new motor mounts put in. I got to talking with the service manager again about my powerloss issues and the occasional stalling at lights and stop signs. He said, "Let'sput the mounts in, give a little while and see how things turn out before we do the trailing plugs or anything else." My repsonse, "What do motor mounts have to do with powerloss issues and stalling?" He said that he's talked to Mazda tech service reps about this and that for whatever reason, they seem to resolve other issues and they are not sure why. Thinking this was kind of odd I went along with it as I still had 14000 miles left on the drivetrain warranty.

I went ahead and bought new trailing plugs, though I have not installed them yet. One of my biggest issues these 4 years were the long road trips, the car getting hot and losing engine power, almost like clockwork, around 45 minutes into a drive I can feel the loss of power during highway acceleration.

So here I am a couple of weeks later, on my drive from NC to NJ, fully expecting the typical powerloss into my long drive. Lo and behold, it was fine the entire trip! With the stops for gas and whatnot, never had a powerloss or stall issue.

Tell me this is a fluke. Tell me motor mounts, the hard rubber gimmicks they put in place of the gel mounts have anything to do with powerloss problems or stalling. Tell me a simple oil change can drastically affect all that.

Tell me something, because this **** is too weird. Monday I'll be driving back to NC so i will once again see if this is all true. My trailing plugs are sitting there waiting to be installed, but i don't want to do it just yet til I figure out what the heck is going on.

 

if rubber in your engine mounts ripps or whatever... use windshield urathane to fill it up and fix it.. thats what i did on some older cars... took the mount off, filled it up, let it dry, put it back on.

 

that the way to do it for sure.. makes for a very solid feeling as well.

 

I had a lumpy, irregular idle and other weirdness, like balky 1-2 shifts..

The way the tech explained it to me was: Turns out that the right-hand-side mount, if weak or broken, can let the knock sensor hit something, which tricks the ECU into retarding the timing to prevent ping, and poof, there goes your idle. Also could cause power loss, I guess.

 

Are motor mounts covered under warranty? Is there a specific recall? I've been experiencing rough, varying idles, and the occasional dip in RPM to a near stall.
I want to know what I need to say to my dealer to get this resolved in a cost-free manner. My 2004 MT has 33k miles on it.

 

This week I took my 47,000 mile 8 into the Mazda dealer. Complained of rough idle, rich mixture on cold cranking, and varying idle speeds, almost to a stall. They looked it over and replaced both lead plugs, both trailing plugs and performed a re-flash. Purrs like a kitten now, smooth as can be. All of it was covered under warranty.

 

MOTOR MOUNTS HAVE A TSB ISSUED!!!
So if you are covered under warranty tell your dealership about the TSB and request the work. Just tell them that you can feel a vibration at idle!
Best fix I ever did on my car. Bad motor mounts will cause a vibration at idle and while driving. This vibration definitely triggers the knock sensor. The knock sensor retards timing and causes a significant power loss. The knock sensor in the RX-8 is especially sensitive and trips sometimes without any reason too! Just look at RB, they remove the knock sensor for dyno testing because of its unreasonable sensitivity.

I love having my power back from new motor mounts.

 

that is 100% true. i've had my motor mounts replaced twice. i've had a rough driving and vibration at idle. now, after they have bene replaced, everything is good.

 

oosik, I'm curious as to how the trip to NC went... I have experienced loss of power on long highway trips at about the 60 mile mark. Kinda like the gas pedal is just ignoring me - and sometimes enough that I can't maintain speed.

I haven't had the mount TSB done yet, but I'm hoping it will fix the problem.