TheColonel

I was in "my friend's" 8 the other night and we were on a fairly level surface waiting at a light. The car was in 1st gear but he had the clutch all the way down. There were no cars around and as a joke my friend revved the engine up to 9krpms to express his displeasure at having to wait for nothing. To our surprise, the car actually rolled forward slightly. He tried it a few more times and every time the engine got up to the 8k-9.3k rpm range it noticeably rolled the car forward slightly. We thought perhaps it was just the vibrations from the engine rocking the car and making it roll forward because perhaps the road wasn't completely level, so we tried again with the trans in neutral and nothing. Put it back into 1st, just holding the clutch down and again it rolls. Is this normal? Anyone else experience this? Or is there a problem with the clutch. He has about 8000k miles on his car if it makes any difference.

RX8_Buckeye

This shouldn't be happening, though it doesn't sound too severe. It would be much worse if the clutch was never fully engaged, resulting in constant slipping of the clutch under moderate to heavy throttle. If anything, I would recommend that your friend get his clutch system checked out during his next visit to the dealership. In the meantime, he shouldn't be repeating that maneuver too often.

TheColonel

"His" concern is that telling the dealership that he's reving the engine like that will make them think he's being abusive to the car and that perhaps thier answer will be "you shouldn't be reving the engine like that".

RX8_Buckeye

He/she shouldn't be worried about that. Revving the engine while in neutral or with the clutch disengaged does not constitute abusive behavior--especially when trying to diagnose a problem. Every owner has the right to investigate potential problems with his/her vehicle, and that requires determining the conditions under which the problems occur. If the dealership has a problem with that, take it up with Mazda Customer Assistance. I don't think your friend has anything to be worried about.

PS: It is acceptable to use "his" instead of "his/her" and "he" instead of "he/she" if the gender of the subject is unknown. Sorry if I offended you. :p

Gyro

the answer is ... problem.


It is loose pressure plate bolts. How do I know this? Because it happened to me, and that is exactly how I found out. I revved the engine with the clutch pedal fully depressed and the car nudged forward. The car should never do this. After it was diagnosed and fixed (it was a wide spead problem with early 2004's) the clutch would not grab at high rpm when depressed, as it should't.

The bolts where not properly torqued from the factory and loosened slightly. My car had 7000 miles when it happened. The starter needs to be removed to expose a section of the pressure plate (clutch cover) and its a straight forward repair after that. Lok-tite can be used on the threads as a precaution.

I would have no problem telling the dealer exactly how it was discovered. It is a manufacturing defect and how it was dicovered is not their business. Besides, revving your engine with the clutch engaged does not harm anything and is not abuse, unless of course Mazda forgets to tighten the bolts. Its their problem and they will fix it for you.

RX8_Buckeye

Hmmm, I should check it out on my car. I've never tried this maneuver, but I worry that my clutch could fail prematurely if it is constantly in contact with the pressure plate, even with light pressure.

Gyro

You can, as it doesnt do any harm, but I suspect you would know already if your Pressure Plate bolts became loose.

Another symptom is the clutch engagement point becoming very "sharp" instead of smooth and modulated. This is because the "spring action" that the pressure plate provides is lost to the whole assembly moving due to the loose bolts. The engagement point itself can move dramatically in the pedal range. For me the engament point moved towards the floor.

Even if the vehicle mentioned in the first post does not have these specific symptoms, the shear fact that the clutch is starting to engage with the pedal fully depressed is a sure sign of the pressure plate backing away.

My dealer at first said "I burned the clutch" and therefore it needed to be replaced. They called Mazda tech support just to make sure and sure enough, they told them about the problem. Apparently it never was widespread enough to make it to TSB level, but Mazda is definately aware of the probelm.

RX8_Buckeye

My transmission has become stuck in 6th gear on two separate occassions! Are you sure this is related to the pressure plate bolts? I haven't noticed anything funny about the clutch engagement point as Gyro described.

TheColonel

When you say stuck in gear, you mean you actually can't pull the stick out of it? I haven't had this, though I have had my gears grind when my clutch is all the way down once or twice. I though maybe I was just trying to shift too quickly.

TheColonel

Oh, and when I do the reving in gaer thing, I can smell clutch after...

RX8_Buckeye

Yes! It was an unpleasurable experience to say the least. It's only happened twice, about 6 months apart, and it hasn't happened in 8 months or so. I also sometimes get grinding during the 1-2 upshift even with the clutch pedal fully depressed, though it is rare. Now I'm very worried.

I did have the dealership look at it, and surprise surprise, they found absolutely nothing wrong. I didn't expect that they would, because the transmission was acting fine when I brought it in.

That sucks... you're being punished for Mazda's manufacturing defect. It's unfortunate that they choose to ignore these problems. It's all about bringing their warranty costs down.

Stop doing it! You're burning up your clutch. Go to the dealer ASAP.

TheColonel

Ok, now I'm scared... I don't want to void my tranny warranty... should I even bring this problem to them or wait till it really brakes?

RX8_Buckeye

Yes, there is absolutely no reason to wait. If the pressure plate bolts have loosened, there's no way they can blame that on you. There's no way they can argue that your abusive driving habits cause the bolts to back out--it simply should not happen under any conditions. If, on the other hand, you wait until it breaks, the evidence may be destroyed.

TheColonel

So this problem can't be blamed on me?

rxeightr

This past Friday I installed an ACT Prolite Lightweight Flywheel.

When removing the stock flywheel, (2) of the Clutch Bolts were loose, although I experienced no ill effects. It was only a matter of time....

TheColonel

My car was warmed up. I suggest you wam it if for no other reason than that you shouldn't rev the engine hard before letting it warm up.

WarpFactor

Can someone tell me if my symptom is related to the pressure plate bolts being loose?

I'm cruising along in 3rd.
Clutch in.
Downshift into 2nd.
I hear the tranny "downshifting" (increase in rpm noise) - Clutch is still in.

To me, it sounds like the tranny is engaging but I still have the clutch down.

WarpFactor

When I release the clutch, it engages and the car drives normally. The car behaves normally in all respects. I just hear the tranny "slowing down" or "downshifting" before I release the clutch pedal.

TheColonel

You may be hearing the syncros.

WarpFactor

I guess that makes sense. Sometimes I just get so paranoid reading about other peoples' problems.

socalightning

Get it fixed right away or it will do more damage down the road. Nothing to worry about really unless you wait.