Weird ticking noise above 2000rpm at low-medium throttle

B6/7 S4/RS4
#1

I just finished installing the coilovers and control arms and everything. been driving the car around occasionally to let the springs settle before I go get an alignment. The car developed this tick noise maybe 20 miles ago - never noticed it before.

I figured it was old gas since the gas in the tank is probably 50 days old since I haven’t driven the car at all. Drove that tank pretty low and filled it up with a new tank of 93. Drove it two or three times since the new tank and the noise is still present.

it happens between 2000-3500rpm and based on the rhythm, it sounds like it’s perfectly timed with the firing of one of the cylinders. I have no codes or anything so I’m lost. It doesn’t make the noise when there is no load on the engine - so putting my ear to the engine and having someone rev it is not going to help. It does not matter if the car is stone cold, or fire hot after a beating.

Here is the video. Excuse the horrible rev matching. hard to film and focus on driving at the same time. You really have to turn up the volume to hear it

http://www.youtube.com/watch?v=86DhTNxt_G0

#2

Exhaust leak? Are your coils secure? How about oil level?

#3

Oil is full. Not the coils. It’s too consistent to be the coils

I was thinking exhaust leak too. A broken guide would make noise all the time I would think

#4

Is the noise at about 1:55 that your talking about?? Almost sounds like the valvetrain is dry, but I’m on a laptop with smaller speakers so it’s harder to pinpoint

#5

No that’s just the exhaust being all raspy because it’s cold. I just watched the video on my laptop and you really need bigger speakers to hear it

#6

Drove 25 miles today hoping it would fix itself. Noise is still there. It’s a tapping noise that speeds up as the rpm’s go up. The exhaust noise drones it out after 3500 or so, so I can’t hear it after that.

I’m starting to think broken guide. But it only makes the noise when the motor is under load or just coasting. It will not make the noise when it’s idling, stationary rev, or engine braking.

#7

You would think that if it was a broken guide that it would make that noise all the time. Load or no load. No codes, right?

Your positive its coming from the engine bay? Do your coilovers have piggy reservoirs? Could they be rattling against a fender?

Just throwin shit out there haha

#8

A/c working okay? Wonder if the compressor is effed.

#9

joe is borderline paranoid re: chains/timing equipment

#10

Joe, I thought you were driving a B5 with the amount of warning lights on your dash!

I tried listening on my laptop speakers, but I can’t really hear it.

I agree though, if it were a guide, I think you should be able to hear it at all times not just some of the time. Based on description I’d say it’s something rubbing etc at the certain frequency of the exhaust or vibration at that RPM. I know the JHM SS stabilizer bushing will make sounds between 4k-6k if you’re catless, but with headers or piggies it won’t. I know you didn’t change the exhaust any, just saying you’ve obviously messed around with a lot of stuff lately and it could be something like that.

See if you can get a better video or use that new mic you just bought to try to isolate it more.

#11

Damn right I’m paranoid!! If this stuff goes or is going, I don’t have the money right now to fix it.

I will try to get a better video today. I can kind of hear it at a stationary rev now. I’ll have my GF rev it slightly in the driveway to try and locate the sound. Still no codes or anything.

mad, I don’t have the stabilizer busing. Just the shifter

#12

I don’t think its a guide Joe. Put the camera under the hood and rev the engine up slowly.

My broken guide made noise at idle and while revving. Load made the noise less noticeable.
Broken guide noises:
http://www.youtube.com/watch?v=ivCf0iAt9ow
http://www.youtube.com/watch?v=n9v9_jLjHqI&feature=channel&list=UL

Maybe you have a noisy injector???

#13

Didn’t you buy a microphone for your gopro not long ago? Try that.

#14

If you had access to a piezo sensor and FFT logging software, you could look to see if it is a cam/valve issue. The vibration signature from these will be a 1/2 x RPM. Also you will be able to pick it up very clearly in the vertical axis on the head. You will also see harmonics of .5xRPM, 1.5xRPM, etc. These are always present, but increased amplitude is the key. also if the noise has significant “impact” events, you will possibly see sidebanding and equally spaced frequencies around a central frequency, and taking readings in gSE, Shock pulse, or some other algorithm related to impact events, these will highlight nicely. If you have a friend with the same car nearby, you can measure his and yours and overlay the FFT’s, see the disparities. Also if you can setup an automated capture, you can turn it on and slowly rev the car from idel to 6krpm, and map out a waterfall plot, and see the frequencies track with engine speed, and as they transition through critical or resonant zones, the amplitudes spike for the driving frequencies. The trick is always identifying the component causing the frequency as well as the resonance. the often are not the same component.

#15

I get what your saying but who has that shit laying around haha! Most dealers might but guaranteed they are up in the rafters collecting dust just like our old VAT-40. We use a stethescope, cheap $20 doctors tool. :slight_smile:

#16

Is your ear calibrated to decipher frequencies? haha! Some guys can do it reasonably well. I have the equipment in my garage so i am at somewhat of an advantage. Anyways if you know people in the physics or geology labs of your local university or college, then they woudl have it as well. Or any vibration analysis outfit. Dealers probably not.

#17

yeah, how’s that mic working out Joe? I need one for my dSLR.

#18

I hate the mic. It’s going back. You can’t hear a thing from it unless you are speaking loudly 5" from it. Anything farther than that is completely blocked out.

Mick, I don’t have those tools, so I used my ear. Had someone rev it and hold it at 2300-2800rpm and poked my head around. Definitely coming from the rear of the motor and I think it’s right between the heads. I felt around to try and find what is creating the sound but no luck. I’m starting to think maybe flywheel

New video: you hear it at 0:04
http://www.youtube.com/watch?v=OoH5DTFmEUs&feature=youtube_gdata_player

#19

Damn that’s strange. Try using a stethescope.

#20

Go get it checked out ASAP!!! I hope its nothing serious bro. . .