Made a vid of my "flywheel noise" , is it the flywheel? ---

[batchman]

New video link didn't work for me. To re-iterate, start with the easiest and most likely stuff first:

Originally Posted by batchman

You may have an exhaust leak.

Originally Posted by Pete

Check for loose exhaust screws.

We will all find injector issues at some point but your first video was not the sound of a dual-mass getting hammered by a misfire.

Originally Posted by alwayscode390

Is this something I should take to a Chevy Dealership

I think it's pretty safe to say you should *NEVER* take a C4 ZR-1 to a dealer under almost any circumstances. The only time I would even consider it was if a friend or fellow enthusiast who knew these cars happened to work at one.

It can be a very trying moment to find yourself with an unhappy sound coming from something nearing exotic. Try not to over-google the problem - you will convince yourself the world is ending. What you really need is a relationship with a corner garage whose work in process includes unusual stuff and whose chief mechanic is a non-megabuck racer of some sort. Maybe that's your "performance garage" or maybe it's not - a lot of those shops are intent only on lightening your personal carry gear (wallet) in my experience.

Best of luck,
- Jeff

[alwayscode390]

Thanks Jeff ... sorry about the dead link , I just updated the first post with a link that works.

If you have time, please listen to it for me.

It doesn't seem like a typical exhaust leak sound to me where you can usually hear an "echo". It sounds metallic to me ... but I will double check the bolts on the headers/exhaust.

I appreciate the advice ! ---

[WVZR-1]

A "lift and a stethoscope" revealed "nothing"? I find that hard to understand. I can't imagine there being an easier method to "locate" the racket. I didn't say diagnose correctly but at least "locate" the source. Once the actual source was revealed I would think suggestions of what is causing it could be maybe more than a "WAG"!

[alwayscode390]

OK, point taken.

I haven't had a chance to get the car on a lift yet.

Once the happens, I am on the hook for a bill from the shop. I was just trying to get a direction to point them in , which I guess has already been done.

Thanks! ---

[WVZR-1]

Originally Posted by alwayscode390

OK, point taken.

I haven't had a chance to get the car on a lift yet.

Once the happens, I am on the hook for a bill from the shop. I was just trying to get a direction to point them in , which I guess has already been done.

Thanks! ---

If you "steer" a shop or "point" you're "on the hook" - if it's on a lift and the stethoscope is used to locate then it becomes a "discussion"! That discussion would be between you and a technician I'm assuming you've got confidence in!

The lift actually wouldn't likely be a requirement - you should be able to likely confirm for yourself the source and the diagnostics also with the car on "all-four" and you on the ground also. You just can't imagine the diagnostics that can be accomplished with a "stethoscope"!

[alwayscode390]

I just noticed the other day that if I move the stick shift left to right a few times in neutral I can hear the clunking in the same area that the other sound was coming from... and it usually sooths the other sound down so its not so bad.

Wondering if I probably have some crap fluid in the transmission that may be too thin and not quieting down the gears?

Just throwing this out there.

I still haven't had the car on a lift ... but it seems like the more miles I put on it , the better the "flywheel noise" has been getting. ---

[BigJohn]

when was the last time you changed your trany oil?

[XfireZ51]

Originally Posted by alwayscode390

I was also told by someone I spoke with at LPE that most Dual Mass Flywheel noises are caused by a mis-fire.

Should I just plan on swapping out the plugs and wires? Besides those , what else causes a misfire ... the injectors or coils?

Would I have a code?

The car idles STRONG and smooth when you look at the tach. I don't hear a miss

Here is the dyno vid and graph. This is with a rattling broken center resonator , it now has an x-pipe in the same spot. The A/F seems solid, the graph seems smooth ... and the car drives GREAT as long as you are over 30% throttle when the secondaries kick in (then all other times its great). Its also putting out the power I would expect it to, its the 465hp LPE package with Watson headers. 43k on bottom end, 20k on top end ---



DYNO:



http://www.youtube.com/watch?v=bMdFUoaL6R4

IDLE Vid :



http://www.youtube.com/watch?v=6ESq4xpNY88

Based on these numbers, I would bet u have a SMFW. AFR is a bit lean at 13.3. Take it to the dyno again and check AFR if you swap injectors.

[alwayscode390]

The tranny oil hasn't been swapped since I bought the car in late December. He told me it all had fresh fluid, but its definitely on the "to do" list. I will use that Castrol that's recommended.

I have only put 1500 miles on the car since then though.

I will do that XFire, thanks guys ---

[SteelBlueZR1]

Definately change the trans fluid to the BMW dealer sourced Castrol product... When I bought my Z I changed tranny fluid to Dexron GM fluid and had gear rattle at idle and whining at revs. Then I got the Castrol fluid for my tranny and could not believe the huge difference it are over GM Synchromesh! Gear rattle and whine gone and shift quality was much better.