My 8 has a sporadic problem where it'll hesitate for an instant just after 4,000 rpm, then feel like it doesn't have quite as much power from there up to the redline.

It's nothing dramatic, a stranger wouldn't notice anything (except the little hiccup hesitation), but after 76,000 miles I know my car lol. When this happens, it just doesn't have that little "kick" in power you normally feel around 4,000 rpm.

Odd thing is, it comes and goes. One day it'll do it for my whole commute, the next day it's fine. And it seems to go away for a few days/weeks if I redline the car a few times, which I of course do to test it once I notice the problem. Otherwise, I rarely redline it.

Does this sound like a sticking SSV? Might redlining the car temporarily fix a sticking SSV?

Is it really true that redlining the car now and then actually does prevent carbon buildup and problems like a sticking SSV?

I saw that there's a TSB on the SSV sticking. Would this be covered under the new 100,000 mile warranty extension?

 

Yes, redlining once a day keeps the carbon away. Judging by how you drive it, I'd say there is a lot of build-up, and is beyond just reving the engine.
No, it's not covered under warranty.
Search around for diy's cleaning the ssv

 

You may want to pull down the front of the catalytic converter and take a look inside. I could be clogged.

 

You sure?

I'm looking at TSB "01-019/08" which mentions, "Some vehicles may experience a MIL with DTC P2070 (SSV Stuck Open). This may be caused by carbon build up near the SSV bushing, which may cause driveability concerns (hesitation and / or lack of power)..."

and says

"This repair will be covered under Mazda’s New Vehicle Limited Warranty term."

I'm just not sure if the extended 100,000 mile warranty covers it?

 

Maries8, I think you're really jumping to conclusions...

How about some maintenance history?
Any CELs? Any codes?
When were plugs, coils and plug wires replaced?
Have the MAF and ESS been cleaned lately?
Have you tried running a seafoam treatment?
Are you consuming oil at a normal rate?

Please consult consult the DIY section for instructions and save money by doing the work yourself.

 

The CEL popped on a few days ago when it hesitated badly under acceleration, BUT it was cold (just started and leaving for work), so I assumed I hit the cold engine fuel-cutoff and that had caused it... so I pulled the "room" fuse to clear it and haven't seen a CEL since (been a few days).

Plugs, wires and coils all replaced about 1.5 years (20,000 miles) ago. When they were failing, the car was difficult to start. But it's starting fine. It does take 4-5 seconds to start, which to me is a long time as it only took 2 seconds when I first bought it, but I assumed a later flash changed things to prevent flooding (along with the new starter and battery).

Nothing's been cleaned, no treatments, oil consumption is OK.

What's odd is how the problem comes and goes. It'll only happen a number of days each month, and the other days it's just fine. Normally when it happened I'd get worried and "baby" the throttle, so the problem (lack of power above 4,000 rpm along with a more "raspy" sound) would stay that whole drive. Now I redline it a few times and that seems to clear it up for a week or so.

I'm guessing a problem with plugs/coils would be consistent?

 

It would be really good to read the codes so you have a place to start debugging.
Plugs and coils should deteriorate at a steady pace so let's put that aside for now.
You can check the SSV two ways. You can move it manually to check that it moves freely or you can watch for it to move as the ignition is shut off. The APV motor is also cycled at shut-off so listen for that.
If your problem is intermittent you should track events to see if you can correlate any events to the behavior.
Try not to jump to conclusions: systematically debug the problems using code readers, data-loggers, or simple visual clues.
I recommend a tool such as the Cobb Access port if you really want to get into this.