weird sound when accelerating in low RPMs
 

Not sure if this is normal but does anybody else experince this metalic noise when say you're cruising in 3rd or 4ths below 3krpm you let off the gas for a second, give it a tap to pick up speed but as soon as you do you hear a noise which sounds like two metal rods making contact. It really gets on my nerves because it makes the car sound broken i have been experincing this noise since the car was barely over 3000 kilometers probably since new cant really remember i never bothered looking into it because i could go a week without hearing it and its difficult to replicate only under certain conditions. If im the only one hearing it i might as well get it settled under warranty soon.

If you're still under warranty there is no harm in having the dealer look at it. Doesn't sound like something I've ever heard.

Thank God my hearing isn't great. I'd have gotten rid of this car a long time ago.

Mods?

None bone stock

Off to the dealer you go! I thought you might've had some mods.

If you were <2000 rpm, maybe it's too much load at low RPM. Between 2000 and 3000 shouldn't make any weird noises.

Throttle body?


I totally gave up trying to figure out what each of the weird noises in my car are about 80,000 miles ago. It still works fine.

If you haven't done so, I suggest you "put a sock" in the sound tube and see if you still hear that sound ......;)


humfrz

I have a sound like a single detonation event if I lift off the gas then apply even a little amount at low throttle. I'm guessing it's probably the AVCS solenoids kicking in for a drastic change in cam timing.

Only engine mod is a sound tube delete.

When I first had my car I took my car into the dealer because I was hearing a weird noise at low rpm. It only appears after the car has been warmed up for a good while, ~30-40 min it seems. They told me the noise was normal. It turned out it was the wonderful noise of direct fuel injection. Look up some videos of other manufacturers' direct injection engines to see if that is the noise you're looking for

By 'two metal bars' sound, are you talking about something like this?

https://youtu.be/0JDAkq-CRac?t=14s

I get the same sorta thing but it’s definitely lower than 3000...

Mine starts at around <2000, but I’ve heard it’s normal. My car works great.


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Some of my friends tell me “your car makes a lot of odd noises” lmao.

I think the worst noises for me are the door switch rattles that I’ve already attempted to lightly insulate.


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It’s not exactly a quiet car

People here say it’s the throttle body and it’s normal.


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I've notice the exact same thing (2017 BRZ). But it doesn't make it all the time. I thing it's pretty rare actually.
It seems to come from the back of the car. I tought maybe it's a thing call differential backlash, where you have a little "play" in the differential gears (something normal), and that going from compression to acceleration the gear make that noise. But it could also be from the muffler. Even tough it's a mettalic sound, I feel like it could be some kind of rapid pressure change in the muffler.

OP, I'm pretty sure my car makes the same sound your talking about. Mine's been doing it for 20K+ miles and no issues so far.

Don't let noises and rattles scare you. I'd be more worried if my car didn't make any weird noises. :bonk:

from reading the comments i feel better about it, its probably nothing. If something breaks in the next 3 years i got warranty so will see.

next time it's doing it, try rolling on the throttle slowly. Does that help?

tip-in knock.


Pretty hot these days?

Sorry to revive an old thread but I’m having a similar issue. I also hear a squeaking sound as I’m applying throttle after shifting but it sounds more of a rubbery squeak. Here is my video of a metallic scratching sound as I jab the accelerator.

https://youtu.be/5Mo9XQ5mrX0

That sounds like tip-in knock. Bad mojo. What kind of engine mods do you have?

Guess my hearing sucks, cant hear anything in that video.

What RPM are you cruising at when you're jabbing the throttle and giving it the beans? I notice it pretty much doesn't happen above 3k at least on my car. Sub 2.5K I can cause the tachometer to waver on demand if I jab the throttle and you can feel the car slightly buck; not good. Engine hates getting anything more than light throttle under 2.5k. Pretty sure it's tip in knock.

I think I was cruising around 2500+ rpm.

As for engine mods, I have a Perrin inlet hose and a blitz air filter. I’m a also running a cat-less front pipe with GReddy Supreme SP catback. Other than that, it’s stock.

asdf

My stock engine has tip-in knock under certain conditions. I haven't yet caught it on logs but hope to on my next highway trip. It only happens during a long cruise when I apply throttle too quickly after a long period of mode-4 (fuel cut) operation, for instance, like leveling out after a long downhill.


It's really disturbing so I've learned to apply throttle slowly in those cases. Sometimes I forget. The sound is soul-crushing.

Soul-crushing sums it up perfectly.

Have you tried getting a stage 1 tune or going stage 2 with headers? Like I said in my previous post the headers and tune cured it and I don't have the sound anymore. I am gonna test stage 1 on stock headers and see if its still there.

Okay so I put my stock headers back on and tuned my car with stage 1 tune from delicious tuning, everything else is stock but the tune. The sound is gone completely. I suggest anyone with this noise get a stage 1 tune at least, I am sure OFT would do the trick.

Hi All,

Well, I never thought id come across the same strange sound that my car makes. A also have a strange metallic flutter noise at low RPM. I used to think it was because of the load I was putting the car under in low gear. It seems more apparent when I have it in 6th gear and running for about 40 mins, tapping the throttle and pushing the engine the problem seems to get worse. I let off the throttle and put it in high gear and the problem goes away.

Tap-in-Knock? is that whats its called, I had it at stock and I am now in stage 2 tune with the works and it still comes back now and then.

I still have this sound guys but much less so since going Catless headers and tune. I have accepted it as a characteristic of the vehicle. My uneducated guess as to why I don't hear it as often now is due to having more torque in that rev band, but every now and again it will do it just rarely.

I used to think it was a rod knock, which I was panicking and went to the dealer. The dealer did a full sound sonic check and everything and said they couldn't find anything.

A garage I spoke to said if it was rod knock then it won't just come and go it would stay and get worse, so it sounds like it's, not rod knock.

I look into tap-in-knock and see what I find.

This car sounds like a farm tractor. It absolutely despises any load at all under 2500 rpm. Unless you are triggering codes it is probably not a big deal.

I never put my car under load below 3500 rpm. I do most of my driving 3 grand and above

I've had the same issue for the last 40k kms. I recall bringing it up once here and Flanders told me it was the heatshield rattle.

It is apparent for me when I accelerate at around 3k RPM 5th or 6th for about an instant when I go on the gas.

The sound came back for me. I didn't hear it stage 2 catless, went back to stock, started hearing it, went stage 1, stopped hearing it but I am now stage 1 for around a month and I am hearing the sound again. It isn't as frequent as fully stock, but its now coming and going.

I was searching other threads about this and it seems like some folks are saying it has to do with the transient ignition retard table, which I know nothing about.

Anyone know anything about that? I am a huge perfectionist and this sound really bothers me :(, I know these vehicles sound like tractors half the time but this specific sound irks me somehow.

http://www.ft86club.com/forums/showt...=123720&page=3

Was searching for TIR related threads and found this one. Listening to the video in this thread and for sure it's tip in knock. I tried to capture this sound with a microphone on my car, but it didn't come out as well as this video.


I don't know what year everyone in this thread has but this issue was mostly solved on the 2017 and newer TIR tables. I have a 2013 which did this really bad but the 2017 TIR table solved it but also caused the car to randomly ignore blips which was crazy annoying. I tried to come up with my own TIR table to avoid the tip in knock but not kill throttle response and never really got it right. Today I run the 2013 table but with E85 and the tip in knock is gone and my throttle response is really good. With enough patience and a lot of trail and error I think you could come up with a good compromise without switching to E85.