Weird Noises From My Car

[Mayuri Krab]

Hi guys,

I had my car's A/C repaired ~3 weeks ago (they replaced the compressor and receiver dryer + de-gas & re-gas) and ever since then my car have started developing two separate noise issues:

Noise 1: "Metallic Think"

There is a faint metallic tink noise coming from the turbo side of the engine, the noise is very faint at idle (have to be outside to hear it) but is most noticeable when I'm on light acceleration (~15-30% throttle), if I'm on hard acceleration (over 45% throttle) then the noise is not really audible since the induction noise from the POD (& engine noise) covers it up.

And finally revving it in neutral or park (car is auto) doesn't seem to make it louder.

Being the pessimistic person I am, I originally thought about the turbo dying but after researching & hearing different sound clips of bad turbos on you-tube the noise doesn't match up (those all had a much higher pitch noise & when revved in neutral sounds much louder) also when I put my ear next to the turbo (next to heat shield) with the car idling the metallic tink noise doesn't seem to be coming from there but sounds like its coming from some area near the POD, underneath where the stock air snorkel sits (is that where the A/C compressor is?).

I thought it could be the A/C compressor but what gets me is the fact that the noise remains even if I turn the A/C off (or the entire fan system off).

Noise 2: "Click/tink noise from center console"

There is a click/tink noise that appears to be coming from somewhere around the steering wheel column to the center console, noise only seem to occur at ~90km/h. If I back off throttle at this speed & drop to 80km/h or below the noise disappears (hence I don't hear it when I'm driving around in normal 60-70km/h roads) or if I drive around 100 - 110km/h there is no noise again.

This noise is much more noticeable compared to the metallic tink noise coming from somewhere in front of the car.

When I took my car to get a minor service done I had the mechanic check it out & he said he didn't find anything unusual & the car seems to be in good working order.

Also besides the noises, the car doesn't feel any different, boost still builds up fine & there is no smoke from the exhaust, which I'm hoping it means its nothing major...

Anyone have any other suggestions on what might be causing the sounds so I can get it checked out? (I'm pretty noob when it comes to cars >_>")

Cheers.

Extra info:

Car is a S1 R33 GTS-T auto with only basic mods (turbo back exhaust + high flow CAT, POD, boost Tee set to 10psi, R34 SMIC & SAFC 2)

[Mayuri Krab]

Did some more "testing" today & found out that the "Click/tink noise from center console" (that general area) is still present even at 100 to 120km/h but just not very noticeable since at those speed the engine is around 3000rpm & the engine noise covers most of it up.

Its only starts at around 80km/h (but will disappear the minute I let go off throttle) & is most noticeable around 80-90 since the engine is at lower rpm on over drive.

Any ideas?

[Mayuri Krab]

Took a video of it last night while coming back home from a Lan.

Video didn't turn out that great (due to using crap phone camera) & there is too much road noise (even with window up) but if you turn the volume right up you should be able to hear the faint "tick"/"click" sound. Its most noticeable from 0:15 to 0:30 & then 0:35 till end.

http://www.youtube.com/watch?v=act11srnJPc

Noise only seem to occur after 80km/h when on throttle, noise becomes un-noticeable if I let go off throttle or if I drive below this speed.

Most noticeable at 80 - 90km/h since engine rpm is low (just in overdrive) less noticeable when cursing at 100 - 110km/h when engine is around 3k rpm which seem to cover the noise up.

[Plan-FAILURE]

Hi guys,

I had my car's A/C repaired ~3 weeks ago (they replaced the compressor and receiver dryer + de-gas & re-gas) and ever since then my car have started developing two separate noise issues:

Noise 1: "Metallic Think"

There is a faint metallic tink noise coming from the turbo side of the engine, the noise is very faint at idle (have to be outside to hear it) but is most noticeable when I'm on light acceleration (~15-30% throttle), if I'm on hard acceleration (over 45% throttle) then the noise is not really audible since the induction noise from the POD (& engine noise) covers it up.

And finally revving it in neutral or park (car is auto) doesn't seem to make it louder.

Being the pessimistic person I am, I originally thought about the turbo dying but after researching & hearing different sound clips of bad turbos on you-tube the noise doesn't match up (those all had a much higher pitch noise & when revved in neutral sounds much louder) also when I put my ear next to the turbo (next to heat shield) with the car idling the metallic tink noise doesn't seem to be coming from there but sounds like its coming from some area near the POD, underneath where the stock air snorkel sits (is that where the A/C compressor is?).

I thought it could be the A/C compressor but what gets me is the fact that the noise remains even if I turn the A/C off (or the entire fan system off).

Noise 2: "Click/tink noise from center console"

There is a click/tink noise that appears to be coming from somewhere around the steering wheel column to the center console, noise only seem to occur at ~90km/h. If I back off throttle at this speed & drop to 80km/h or below the noise disappears (hence I don't hear it when I'm driving around in normal 60-70km/h roads) or if I drive around 100 - 110km/h there is no noise again.

This noise is much more noticeable compared to the metallic tink noise coming from somewhere in front of the car.

When I took my car to get a minor service done I had the mechanic check it out & he said he didn't find anything unusual & the car seems to be in good working order.

Also besides the noises, the car doesn't feel any different, boost still builds up fine & there is no smoke from the exhaust, which I'm hoping it means its nothing major...

Anyone have any other suggestions on what might be causing the sounds so I can get it checked out? (I'm pretty noob when it comes to cars >_>")

Cheers.

Extra info:

Car is a S1 R33 GTS-T auto with only basic mods (turbo back exhaust + high flow CAT, POD, boost Tee set to 10psi, R34 SMIC & SAFC 2)

OK.....

Noise 1

Check all your heatshields as one could have loostened slightly producing a rattle/tink sound - if its turbo side check your turbo and manifold shields.

I see you have a SMIC so the chance of the engine fan touching/clipping the piping is probably NIL - mine was making a slight tink at idle due to my FMIC dropping slightly (weld actually cracked on the FMIC support mount) but the noise would dissappear when the revs were raised to a bit above idle

Noise 2

Probably the same noise as noise 1? Your just hearing it from the centre console?

The fact that it is more audible than the other tink is consistant with it being closer to you than when standing outside the car.

If its definitely a different sound I would be taking it to a reputable workshop with a "noise tracer" (similar to a radiation detector seen on CSI or something - we had one in our workshop, i think it was Snap-On) which will be able to trace where the sound is the loudest and hence give you the source of the noise.

I'd definitely be checking out the heatshields and anything thats getting in the way of your engine fan first.

Jimmy

[Mayuri Krab]

Update.

Noise 1

Appears to be radiator is loose or something loose around that area.

I discovered a small crack on the plastic bit of the radiator & after I got it fixed the noise have gone down to pretty much inaudible now.

Noise 2

Appears to be just a 'normal' noise & I'm just being a paranoid dick

Since driving my dad's Corolla (06 model) up to Albany from Perth (~400km trip) I noticed that car made the same click/tick noise around 90 to 130km/h (although not as loud).

But insulation from road/tyres noise maybe?

Edited March 8, 2011 by Mayuri Krab

[Mayuri Krab]

Another update.

Found the real culprit to the 1st noise!

Found an old 1/2 moon seal that was left near around the engine & lodged underneath some pipes & wires, who ever changed my rocker cover gaskets must have left one of the old ones there while they put all the stuff back on top.

No more think noise under acceleration!