Faint metallic noise during acceleration
02-13-2007, 04:21 PM
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Faint metallic noise during acceleration
Okay, so in 3rd gear and above, when I take my foot off at around 6000rpm, and then re-apply (so the car is accelerating from 6000rpm), I hear a metallic sound, like a slight metal-on-metal brushing that is constant and doesn't vary with RPMs. Interesting note -- the sound sometimes simply doesn't happen. This sound did not exist before.
I became aware of the sound right after I changed my tires (got into my snow shoes, dunlop wintersport m3s (fr215, r245 -- default sizes, brand new). The sound is on/off still at over 300 miles of driving with the tires. I had an oil change coming up, so I had those done to rule somethings out.
Here's the situation now:
-The car is properly heated (no hard acceleration / rpms under 3k until engine reaches operating temperature).
-The road is dry.
-Tires are new, but have been broken in (~300mi, broken-in enough to cross it off)
-Alignment done properly, after tires were broken in. UK spec used.
-Engine and transmission oils are brand-new (magnetic transmission oil drain plug had nothing on it, oil was clear gold in color).
-Car is bone stock, everything is Honda (everything has 10k miles on it, taken very good care -- oil changes have been at every 2500 miles since 5000mi).
-No smoke coming out from the back, doesn't burn/use any oil.
-Car has never been oil-starved.
-Performance feels unchanged.
-I've never mis-shifted in a way to cause a mechanical over-rev.
-I've never launched the car.
-I don't 'drift' with the car, only let the rear kick out seldomly when turning from a stop.
-Other than that, car is driven very hard. I use VTEC in 3rd, 4th, 5th and 6th gears on the highway very often and for prolonged periods of time. 20, 30 minutes of VTEC at a time, hovering between 90 and +150 miles -- there are nights in which I'll make a 20 minute run, make a U-turn and do the same run in the other direction, and so forth.
-A sense of how the engine is treated during these 20-30 minutes: I'll take my foot off the throttle at ~8800rpm, wait for something (a car to move, etc), and then reapply around 7500-8000, and finally shift out of that gear at 8900-9000rpm.
-I seldom let the fuel cut-off kick in the city (1st or 2nd) for the novelty of it, yeah it makes no sense, but I do it nonetheless (maybe once a week (at most))
So here's pretty much what I can say about the noise:
-It only happens when the car is in gear (3rd and above) -- I've revved the engine in neutral at a standstill and was not able to hear the noise (perhaps 1st and 2nd are too short to hear this noise? they pass by too quickly?).
-It only happens when throttle is being applied over ~6000rpm (safe to say this only happens in vtec, then?).
-The noise is constant, it doesn't vary with revs. It doesn't oscillate either, just a constant metal-to-metal brushing (I want to say scraping, but thats a bit too severe) noise. Think the rubbing of two metal bars but softer, and constant (until I take my foot off the throttle).
-The noise is gone when I take my foot off the throttle, and comes back immediately when throttle is applied.
-Noise sometimes doesn't happen.
[I live in Europe. Car is EUDM, 2.0L, F20C2]
Here are my thoughts (as if this post wasn't long enough, heh):
-If this were a bent, dropped valve (for whatever reason), it would've destroyed my engine already.
-If this were the timing-chain-tensioner (TCT), it would make a loud bike-spoke+playing-card noise at idle that would vary with revs (IIRC?)
-If this were a piston-related issue, it would make the noise when the car isn't in gear, and it would probably vary with revs.
-Seems the problem is isolated to VTEC, and acceleration combined. The performance cam? the intake manifold valve? things that might be moving when my foot is on the throttle that weren't moving otherwise?
I became aware of the sound right after I changed my tires (got into my snow shoes, dunlop wintersport m3s (fr215, r245 -- default sizes, brand new). The sound is on/off still at over 300 miles of driving with the tires. I had an oil change coming up, so I had those done to rule somethings out.
Here's the situation now:
-The car is properly heated (no hard acceleration / rpms under 3k until engine reaches operating temperature).
-The road is dry.
-Tires are new, but have been broken in (~300mi, broken-in enough to cross it off)
-Alignment done properly, after tires were broken in. UK spec used.
-Engine and transmission oils are brand-new (magnetic transmission oil drain plug had nothing on it, oil was clear gold in color).
-Car is bone stock, everything is Honda (everything has 10k miles on it, taken very good care -- oil changes have been at every 2500 miles since 5000mi).
-No smoke coming out from the back, doesn't burn/use any oil.
-Car has never been oil-starved.
-Performance feels unchanged.
-I've never mis-shifted in a way to cause a mechanical over-rev.
-I've never launched the car.
-I don't 'drift' with the car, only let the rear kick out seldomly when turning from a stop.
-Other than that, car is driven very hard. I use VTEC in 3rd, 4th, 5th and 6th gears on the highway very often and for prolonged periods of time. 20, 30 minutes of VTEC at a time, hovering between 90 and +150 miles -- there are nights in which I'll make a 20 minute run, make a U-turn and do the same run in the other direction, and so forth.
-A sense of how the engine is treated during these 20-30 minutes: I'll take my foot off the throttle at ~8800rpm, wait for something (a car to move, etc), and then reapply around 7500-8000, and finally shift out of that gear at 8900-9000rpm.
-I seldom let the fuel cut-off kick in the city (1st or 2nd) for the novelty of it, yeah it makes no sense, but I do it nonetheless (maybe once a week (at most))
So here's pretty much what I can say about the noise:
-It only happens when the car is in gear (3rd and above) -- I've revved the engine in neutral at a standstill and was not able to hear the noise (perhaps 1st and 2nd are too short to hear this noise? they pass by too quickly?).
-It only happens when throttle is being applied over ~6000rpm (safe to say this only happens in vtec, then?).
-The noise is constant, it doesn't vary with revs. It doesn't oscillate either, just a constant metal-to-metal brushing (I want to say scraping, but thats a bit too severe) noise. Think the rubbing of two metal bars but softer, and constant (until I take my foot off the throttle).
-The noise is gone when I take my foot off the throttle, and comes back immediately when throttle is applied.
-Noise sometimes doesn't happen.
[I live in Europe. Car is EUDM, 2.0L, F20C2]
Here are my thoughts (as if this post wasn't long enough, heh):
-If this were a bent, dropped valve (for whatever reason), it would've destroyed my engine already.
-If this were the timing-chain-tensioner (TCT), it would make a loud bike-spoke+playing-card noise at idle that would vary with revs (IIRC?)
-If this were a piston-related issue, it would make the noise when the car isn't in gear, and it would probably vary with revs.
-Seems the problem is isolated to VTEC, and acceleration combined. The performance cam? the intake manifold valve? things that might be moving when my foot is on the throttle that weren't moving otherwise?
02-13-2007, 05:06 PM
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if its a metallic ringing noise its probably the shifter. its a common problem...scared the shit out of me when i first heard it on my car 
...doesn't happen all the time..and when it does its always on hard accell past 6k rpm...easiest way to see if it is the shifter..and i've done this so i know it works...when you accell up and you start hearing the sound...put your hand on the shifter and while its in gear...hold it to the left or right...like put pressure on it sideways until you can't...you don't need a lot of pressure but this should stop the ringing and immediately when you let off the pressure it should come back. then you'll know...i guess there's a procedure in the service manual that when you get your clutch done they are supposed to lube the shifter and most places don't do it right. either way LUBE YO SHIFTA@#$% hehehe
...doesn't happen all the time..and when it does its always on hard accell past 6k rpm...easiest way to see if it is the shifter..and i've done this so i know it works...when you accell up and you start hearing the sound...put your hand on the shifter and while its in gear...hold it to the left or right...like put pressure on it sideways until you can't...you don't need a lot of pressure but this should stop the ringing and immediately when you let off the pressure it should come back. then you'll know...i guess there's a procedure in the service manual that when you get your clutch done they are supposed to lube the shifter and most places don't do it right. either way LUBE YO SHIFTA@#$% hehehe
02-13-2007, 05:26 PM
#3
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i made a thread a few months ago about a metallic ringing sound i heard on accel. a couple of 06 owners also noticed the same thing. someone even said it was louder after putting a test pipe on, say theres a chance it had something to do with the exhaust. except, the sound i hear will go away after some hard driving(maybe having to do with the exhaust getting very hot).
02-14-2007, 12:44 PM
#5
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i wasnt saying it was from a test pipe, someone once said that the test pipe made it 'louder'. so with that said, it was most likely related to the exhaust. there is a lot of thin metal under there, and metal likes to ring. good luck 
