2G Noise During RPM Range

[spyderdrifter]

Since this last weekend, I've been hearing an odd ticking/knocking sort of sound, but only during a limited range of rpms. It happens between 2500 and 4000 rpms, mostly in 1st and 2nd, but kind of faint through the rest of the gears. It's faint, but there. I haven't done anything to the car recently other than put in a black dash. Today after work, I started the engine and was looking around under the hood for anything obviously out of place. Everything looked normal, but there's a similar sound coming from the trans side the bay, not sure if engine or trans, but after how loud it was, I'm leaning more toward a transmission or clutch noise. I have an ACT 2600 un-sprung 6-puck with pressure plate, new throw-out bearing since I built the engine. It's not oem, but was new. Another reason I'm leaning toward a clutch noise is that the clutch will make another noise while at idle, but stops when I disengage the clutch. I also read a long time ago about cruising in 5th gear and letting off to see if the shifter wiggles, so I did that, and my shifter does wiggle, but not a lot. Should I pull the end case off to see if the 36mm shaft nuts are tight? I'm not sure what all to look at to pin point this noise, so I'm open to suggestions. My build journal probably isn't up to date, so the important things are, 96 TSi AWD, manual trans, oem long block, ebay 16g, and gauges. I don't yet have my wideband installed.

 

[chrysler kid]

If it goes away when you push down on the clutch its just a noisy throw out bearing. Its a crappy design that actually uses ball bearings that dry out over time on the shelf. More modern vehicles use oiled discs in a sealed chamber to roll across the clutch disc, which is also a disc......


Anyways. I had an output/input shaft go bad and it would rattle no matter if I had my foot partially down on the clutch while accelerating to put pressure on the throw out bearing. It sounded like a wheel bearing but it was load dependent and rpm dependent and eventually turned into a very loud rattle and then my axle seal started leaking because there was too much pressure on it from the output shaft bearing having internal damage and putting too much force downward onto the axle instead of just rotating the axle, and resting on the bearing

You could adjust your master cylinder for proper engagement or add a shim to the slave. Hypothetically it could be your clutch fork has an air gap to the clutch pressure plate and the throw out bearing is rattling against the fork

 

[jakk220]

Maybe the Flywheel bolts are starting to come loose? Did you loctite them when you put them back in?

 

[spyderdrifter]

Sorry I've been really busy and forgot about my post here.

No, I didn't use loctite on those bolts, but I never have, and I have never had flywheel bolts loosen. That's not to say it couldn't happen, just I never have.

As for what you're saying Chrysler Kid, it very well could be only the throw out bearing, which I'm sure the noise that goes away when pushing the clutch is the bearin, but the other noise really can't be I think. I need to get a video some how. It almost only happens while driving, and the bearing noise is only at idle. They're seperate noises too.

Also since this noise started, not the bearing noise, my ECU has been throwing the P0400 code, but I removed all the emmissions while building the engine.

 

[rEclipserGST]

If you are hearing a noise in that range, I would put the car down. You are hearing two noises. More than likely its a throwout bearing and rod bearing. Verify pulleys and balancers are okay. Crank pulley is bolted. Harmonic Balancer is in good shape.

I do not know the P0400 off the top of my head. Its for EGR. So, do you have link? I do not see any info in your profile about your tuning setup or ANY mods.

 

[spyderdrifter]

There's no mention of Link or mods because there aren't any right now. The car needs maintenance first. I know what the P0400 code is, but only mentioned it because it came on when this all started, but it's weird because the emission parts were all removed and blocked off.

 

[spyderdrifter]

Here's a quick update to this issue. The noise has gotten a bit louder, and only occurs during light to moderate throttle. As soon as I punch the pedal for boost, or let off so the throttle is closed, the noise is gone. Rpms don't change the speed of the clicks from the noise. To me, it almost sounds like a slim chance of it being the crank trigger hitting the crank sensor. But I don't want to jump to that assumption. I've been through that before, and don't want that to bappen, but it's coming from that sixe of the engine. Gonna check this weekend if not sooner just to hopefully eliminate the possibility. Any thoughts out there tbat could be relevant?

 

[chrysler kid]

You're worse than my walk in customers at AutoZone,

"I have never popped the hood or looked under my car, why does it make this noise?"

Stick yet head under there and look at it. It's not gonna bite you

 

[spyderdrifter]

I do crawl under my car and tinker, listen, & search for causes. When I can't figure ut out on my own, I come here and ask...

 

[Kryndon]

I'm also leaning towards the throwout. Next time you go for a drive, find a steep-ish incline and go up on it with maybe a steady 40-50% throttle. As soon as you hear the noise, continue going up and start pressing on the clutch pedal more and more until you actually fully disengage it. If the sound stops at any point, note when it does so. This can tell you if the noise is somewhere on the engine side or tranny side (or just a noisy throwout and a worn clip). The steep incline is usually better for testing as it puts more load on the power/drivetrain and doesn't require you to accelerate too much.

 

[donniekak]

This is what you need.
https://www.amazon.com/Buorsa-Steth...ocphy=9015231&hvtargid=pla-473283247561&psc=1

 

[spyderdrifter]

This is what you need.
https://www.amazon.com/Buorsa-Steth...ocphy=9015231&hvtargid=pla-473283247561&psc=1

I got one already, but it's hard to use it when the noise only occurs while driving. At idle, there's nothing.

 

[donniekak]

If it won’t make the noise sitting still revving the engine through that rpm range, it’s probably your transmission.

 

[ChessmoDSM]

If it won’t make the noise sitting still revving the engine through that rpm range, it’s probably your transmission.

Or anything else that could be moving when its not idle.. Have you tried to take it out of gear when you hear said noise and see if its still there when coasting?

 

[spyderdrifter]

I have pulled it out of gear while moving and left it in gear and pushed in the clutch while moving. The noise goes away each time. I got a new trans and t-case over the weekend, but don't know when I'll get the chance to swap them. I also don't want to swap the trans and end up being wrong about where this noise is coming from.

 

[ChessmoDSM]

Sounds like you have either a chattering TOB/or a input shaft bearing, hell it could even be a noisy synchro

 

[spyderdrifter]

Well I know the tob is noisy for sure, and my 2nd and 3rd gear syncros are going, but this noise still sounds like it's coming from the timing area or the short block.

 

[donniekak]

Have you revved it in neutral while using a stethoscope? It’s real easy, just pull the throttle with one hand while moving the probe with the other.

 

[spyderdrifter]

Yes, and I haven't heard anything yet.