I am trying to find out what the heck these sounds are coming from. They were not always there, I just noticed them about a week ago.

Here is my idle knocking:
www.myrx7.com/images/damian_idle_knock.mpg

Here is my engine rattle:
http://www.myrx7.com/images/damian_engine_rattle.mpg

Ok, now, they may be totally unrelated and the more important once for me is the engine rattle. It starts that rattle around 2k rpm to 4k rpm, ...also if you gass is hard the rattle is barely noticable, but slow accell and it rattles nasty like in the video when i rev it in nuetral. I took the transmission out to rule it out for noise, and we tested a ton of things, so it has to be somthign REALLy obscure. One important note, this rattle does NOT affect the performance as I can tell, it runs fine, boosts fine, power is fine, air fuel ratios are fine, idle is good, vacuum is good, et, et. We checked the exhuast sleeves, turbo hitting car frame, ruled out a bad ICV, re-padded things that might be hitting together, and other stuff bouncing around, .... nothing we found made the noise.

any idea? any one herd this sound before and know what it is?

 

Where you just driving one day and all sudden it started making that noise? I've never heard anything like it. I know that the 1st trbo kicks in at 2000rpm and the 2nd around 4000rpm. Maybe it has somting to do with 1st turbo.

 

fisrt sounds sounds like the motor externally knocking the firewall or somewhere in there. the second no idea. could it b e a waterpump gear? or one of the other close by pulley gears?

 

1st one im not sure but the 2nd one def sounds like a waterpump bearing..

 

well, it may have slowly started but my car is so loud that I didnt hear the sound tillit got to this point, so to me it was just there all of a sudden.

this is my single turbo track car

 

hmmm, interesting on the waterpump idea for the rattle.

 

have you herd this before, is that why you think its the waterpump bearing?
I'll look into the waterpump tonight.

 

have you checked your exhaust (manifold and mufflers) for any kind of small leak or crack?

 

Did you try using a stethoscope to find out the area from which the knock is coming from. Sounds just like a spun bearing...........but you know.

 

yep, checked all the exhuast, its not there.

 

It is possible they are from the same source. I would try a pipe or mechanics stethescope to pin down the source before turning any more bolts.

 

ohh god, not another spun bearing!!! :-( heheheh

the pully is not moving around like a spun bearing...and the car runs pretty well so i dont think that is it.

 

from the info you gave us (engine runs great, boosts great etc etc) and judging the sound from the second video and from personal experience, i can say its most likely a waterpump bearing..

 

its possible, but the idle noise is systematic (pattern), the other engine rattle is not, its randome jumbaly mess noise, no pattern to it other than when it starts. But, they still could be related.

I'll try the mech stethescope idea, thanks!!

 

The car could still run fine with a spun bearing, I have had a car or two with spun bearings and you wouldnt know performance wise just for the sound of a couple wrenches in the oil pan. I reallly dont know how a fd acts.......I hope to never know!

 

ok thanks for the info, ill pull the waterpump belt and spin the motor to see if still makes the noise, steve kan suggested I do that to rule out the waterpump before tearing it all apart.

 

guess its possible, but then wouldnt it make the noise all the time, not just in an RPM range?

 

In your idle video I thought there was a knock? I dont understand what you are saying?

 

I had a very similar sound last time my clutch went out, just a thought.

 

After listening to the vids, It seems to be loudest by the opening in the bellhousing. (both vids) When you move around the knocking sound seems to get quiter. Are all the bolts tight on the flywheel? could one have come lose or completly off and is rattling around in there.

Just a different opinion than the rest.

good luck
Brandon

 

we removed the clutch and trans when we did the test, in teh video it just has a dummy bellhousing on it to hold the starter, only the flywheel is attached.

 

good input but been there and done that, its not the flywheel, i even removed the flyw heel and counterweight, it wasnt the issue.


the sounds does seem like its from that area but we cant tell if its resonating to that area or if the sound is being reflected back there.

 

Did you rule out the starter? Not to shure how it would make this sound but maybe a possiblity. Not disengaging all the way.

 

yep, we tested it, chedk to make sure it was retracting, et, et.... didnt seem to be the problem.

 

Well, I will keep brainstorming.