https://youtu.be/heCXK5KTI80

My car has a d16y8 that has been making a grinding/scraping sound at idle and near it. This has not affected drivability but worries me as it is my daily driver. The sound seems to be coming from the transmission side of the engine but it is hard to tell. The clutch was done 5000 miles ago with new flywheel bolts properly torqued with loctite. Thank you all for the help I will supply any information needed

 

Open the distributor cap and see if the rotor is loose..

 

thank you sir I will immediately check this. I put a new distributor on it recently because the ignition coil failed and I could not get the screws out

 

I opened the distributor and the rotor was not loose. I removed the dust cover to see if it would help but nothing changed. My rotor and cap have wear as if they are high mile but was replaced ~ 1500 miles ago, do you think this could be the problem?

 

 

I reinstalled my OEM worn out cap and rotor, the sound did not seem effected by this action

 

Does it make the grinding sound at a certain rpm? say 1500 rpm? and does it go away after it revs past that point?

Some things it could be are maybe the starter gear is grinding on the flywheel,

loose connection on the header collector or broken weld inside the header collector,

was there any issues after the clutch change? or basically this sound came from out the blue or suddenly correct?

 

The sound happens at idle but gets more intense at around 1500-2000. The sound can be heard at hwy speeds at 2500-3000rpm but past that the car is too loud to hear the sound.it is also not constant and will spot momentarily then come back. I have taken the starter off and the flywheel did not seem damaged but it could be the issue as it has an xtd lightweight flywheel.

What would be the best way to test if it is headers? It sounds like it is coming from inside the engine. I do not remember issues after the clutch change (6000 miles since replaced) but recently the car has had a problem of wanting to start going before the normal clutch bite point. My friends theory was that maybe the flywheel bolts were grabbing but it's not consistent at all. The sound did not occur after the replacement or I did not notice. Thank you all for the help

 

This video was filmed 1 hour after the original video. Engine was at operating temp

 

Well they sell scopes you can use to touch areas of the engine to pick up the sound, head over to harbor freight they sell them for like $8 it looks like what a doctor uses to check your heart beat, probe all areas till the sound really picks up and you pin point the area for a better idea of where its coming from.

Check the clutch slave and master cylinder, the master cylinder you can adjust so the clutch engages or disengages where you like.

 

Okay I will get one tomorrow as my local store is closed. I do not leak clutch fluid but it may be an internal seal. I will update anyone following this in maybe 12 hours thank you.

 

I went and bought the stethoscope today. The noise seems to be originating from the transmission side of the engine or inside the bell housing. I was able to bring my idle down with a good coolant bleed, sitting at 8-900rpm the sound could not be heard but with very slight throttle it would pick up. The sound could be heard at 11-1500rpm but after that it stops or is drowned out. From what I can tell the sound is limited to that specific rpm range. The most notable points were directly under the distributor, and on the block under the headers although more drowned out. It could also be heard on the valve cover. The starter/ clutch system does not seem to be the origin of the sound. Placing the stethoscope directly on the transmission did not indicate the gears were the problem. I have also had the oil pan and valve cover off multiple times with minimal metal on the drain pan bolt and in the oil during changes. Is it a possibility of being a bearing somewhere or pressure plate does not clear the housing? It is a cheap kit that came with the car as it had a bad clutch.

 

I agree it is sound from the trans...my guess is a bad throw-out bearing or pilot bearing. Does the noise get worse when you slightly push the clutch in?

 

The noise does not seem greatly affected by movement of the clutch or at all. I put the throw out bearing and the new flywheel had a bearing in it as well but my friend with experience told me we did not replace the entire bearing. Could this be the cause? Having the clutch to the floor or with slight pressure anywhere in the throw has no effect at my current cold idle of 1500rpm. Thank you (xtd stage 3 kit with clutch, pressure plate and flywheel)

 

The bearing is mounted in the flywheel so it needed to be the new bearing if it was a new flywheel

 

I was told it possibly could be a bearing inside the engine but the crankshaft has turned most likely millions of times with it like this and I would figure it would have thrown a rod by now, I will pull the engine soon and investigate further or check other things if anyone has any ideas. Thanks for the help

 

Check the collector on that header i bet you that's where its coming from! best thing is to try a different header! I've heard that sound before and it came from a broken piece inside the header collector as strange as it sounds try checking that.

 

Do all d series manifolds work? I just helped my friend pull a y7 to throw in his eg hatch and It has a stock manifold I could throw on. I should be able to do this soon within days, I will get back to you for any results.

 

Yes if its from a D series it will fit but might not bolt up to the exhaust but even open header you should tell if the sound is still there it will just be really loud as it idles open header
And also take a flash light and look inside the collector flange and look for anything broken inside that would vibrate as the exhaust flows out.

 

Okay I will give this a try when he is off work and not busy. What would be the best way to inspect the header? Do you recommend that I just remove the header and throughly inspect it and maybe give it some good shakes?

 

Yea pull it off and look where the collector bolts to the exhaust piping.

 

The noise turned out to be an exhaust manifold nut stuck in between the ac compressor and its "mounting plate".

 

Sweet! I'm glad we figured it out!