Sound on pressing acceleration

[Mikastef]

Dear all,

My YARIS is a 1000cc engine which drives 100km every days, for six days a week. It has an automatic gearbox. I am approaching 100,000km and I am quite proud to say that this yaris is a very reliable car indeed...it has never failed me ....for now....and I plan to make it go over 200,000km...hopefully ...

I am very very disciplined in servicing it every 8,500km and do a lot of preventive maintenance. I change all fluids in due time.

My daily trip consists of 50% highway driving and the rest, a mixture of traffic jam and normal driving .

But lately, I am starting to hear some strange sound upon pressing the accelerator pedal. The sounds characteristics are as follows

-It occurs at random...say 40% of the time....not every time!!
-I noticed that it occurs mostly when I am driving around 30-70km/hr, and it is more pronounced when I am overtaking a vehicle and pressing more on the pedal. It nearly never occurs (or I don't hear it) when I'm driving over 90km/hr..I think when I put some serious load on the car in the 30-70km/hr range that I can hear it mostly...for eg. When I'm driving on a hill, overtaking, just slowed down after a hump and then accelerating fast to speed up..

The degree of occurrence decrease at night...since perhaps there is no load on the car as the road is very clear and I can drive at ease ( few stop and go)...it also never occured when I am going downhill.


-it seems to be a metallic sound (like pebbles shaking in a bottle lightly..or like a light metal rattling/hitting lightly against each other...)....-I am still trying to record it but it occurs randomly and thus is quite difficult to record...
Once I get a good recording of it, I will post it.

-I feel that the sound occurs in the engine bay, in the driver side corner (where the water pump, accessory belt etc are found ). Sometimes my ears and mind plays me tricks and I feel it is at the back of the car :smile:


I have made some research online and some pple say that it may be due to
1. Heat shield which is loose -nope.i made a mechanic checked my heat shield and apparently it is good and not loose.
2. It relates to gas octane ratio ..- well I have changed fuel stations so many times. And it random occurrence makes it difficult to know for sure if it related to this problem.
3. Transmission problem - I pray that it is not.....!!!!!! But I don't get any gear shift problem. My transmission is smooth.
4. Loose Vacuum or dirty throttle - well I didn't check the loose vacuum yet.and some 30,000 km back I did make the mechanic cleaned the throttle.
5. Brake pad - i still have some brake pad left.
6. Axle or cv joints - nope. I don't have any problem when turning. My car is smooth when I'm turning.
7. Water pump -but it occurs mostly on acceleration...so how is it related to water pump??? And my car temperature seems ok..ranging around 85-95 degree. I plan to change the water pump when I reach 100,000km.
8. Bearing - wheel? Other bearing near the water pump?? I don't know..didn't check yet.
9. No error code either through OBD Scanner
10. Timing chain going bad- my god...this is going to cost a fortune to change ! I hope not..the car is still young...

Please help me...
I noticed that mechanic sometimes does not know your problem exactly...and it is up to us, the drivers that give the mechanic all the clues for a successful diagnostic. Else we run the risk of spending lots of time at the mechanic or, the car may get damaged eventually due to bad diagnostic .

[bronsin]

Cold engine. Take the belt that runs the water pump etc off. Start the engine and drive the car. If it doesn't make the noise, the noise must be in one of the accessories the belt drives.

Note: car should make the noise, then take the bely off and BRIEFLY run the car.

If it does make the noise, then you didn't discover the problem and its not in the accessories.

Yes by all means post a recording of the noise.

PS Most noises are not a problem. You will get used to it over time. Something has rattled since Day One when I back up. Its a cable I learned from here and Ive never fixed it. When it first happened I thought it was worse than Global Warming.

[nookandcrannycar]

Something has rattled since Day One when I back up. Its a cable I learned from here and Ive never fixed it. When it first happened I thought it was worse than Global Warming.

:bellyroll:

[Mikastef]

Hey Guys.
I have managed to record a bit of this sound... well it is a very faint sound alongside the engine sound.
Total time: six second.

https://www.dropbox.com/s/w3a7udwj35kjs55/001_A_002_Mika_Z0000044-2.mp3?dl=0

The strange sound basically appear first at 1 second, and then between 2.5 second to 3.5 second. you will hear that it is not the engine. And normally I get the sound more "INTENSE and Louder" than this recording. I mean, sometimes it is loud and continue for 2 - 5 second when accelerating.

Here it is rather faint and last less than one second...

(Basically, I took my voice recorder from my University days and attached it in the engine bay and started driving for 1 hour).. I had to basically listen to the whole one hour recording to get this one second sound !)...

Do tell me if you are able to listen to it or to download it...
thanks a lot for your help

[Mikastef]

Oh, btw three folks out there were so kind to tell me that their previous acceleration sound came from:

1. Water pump
2. Bearing
3. Timing Chain

So I hope it is either one of these and the problem does NOT lies in the engine or the automatic transmission :eek: !!!
This is driving me nuts..

[Bluevitz-rs]

The exhaust gasket off the manifold might be blown out. I just changed mine because it was making noise on acceleration too. If you've never heard it before it can sound a little like you're describing.

[Mikastef]

Have you been able to listen to my sound in Dropbox?

Is the exhaust gasket expensive?

[Bluevitz-rs]

just listened to it, I can't really tell what that is.

If you have look down at the connection, you'll see water spots around the leak, if it's leaking. Also if you have an auto it's easy to do a test in your driveway. In drive, hold your foot on the brakes and put some load on the engine. Then try it in reverse. You'll definitely hear the leak if it's leaking.

[bronsin]

Or (with the engine cold) start the engine and hold a folded rag over the tailpipe. Make the rag seal the pipe. If there is a leak anywhere in the system you will hear a hiss. If there a real hole you wont feel any pressure at all.

[Mikastef]

thx for the feedback....
I will try to arrange a meeting with a silencer specialist or mechanic next week (this week im busy).
But three months ago, I did check it with my mechanic and it said there is no leak and the heat shield is ok. I wonder if the problem lies in the exhaust pipe itself...
Hope it is not a serious issue....

So anybody think it might be a transmission/engine issue?
.... I hope to get other's people feedback/experience too

[Mikastef]

I came across this:

Engine Ticking
Engines that tick are quite common. The most common problems that cause ticking include:
Engine valves being stuck or that need adjustment
Sludge in the engine
Valve lifters that have collapsed
If your vehicle is making an odd noise, it is time for you to bring it into the shop for car maintenance. This will allow you to have your vehicle inspected and repaired promptly before any major damage is seen

I will need to check this with a mechanic next time since I guess nobody got this issue here

[bronsin]

Um...while there MAY be something really wrong most likely its not serious. A "well trained" machanic can take you to the cleaners if you are not careful!

[Mikastef]

So guys , I went to BOSCH CAR SERVICE today. Couldn't go Toyota since it is closed on Saturday.
So they put my car (and me) on an elevator around 2meter high and told me to accelerate.after 10 min of acceleration and inspection, they said that apparently all my other bearing (water pump etc ) seems ok. It also seemed to have no leaks around the exhaust connections (from engine to back of the car).

They did a 'sight' inspection mostly but was quite thorough. They looked underneath the car's engine bay. And I also got the opportunity to swap place with one of the mechanic to look underneath it.

Apparently they think they heard something around the place where the gearbox meets the engine (I didn't - but my ears aren't that well trained). They said that perhaps a bearing near this connection is going bad and I need to go to the agency...(isn't the automatic gearbox made up of lots of bearing??!)...they said that it does not seem to be the gearbox itself but the connection between the gearbox and the engine. Apart from this possible problem, the car seems fine. When I was on the elevator, I didn't hear the car made its usual strange sound, perhaps because the car wasn't really on 'load' as it was accelerating in the air effortlessly.

..I pray that their diagnostic are wrong !...I don't have gear slipping or something..my gearbox seems fine when I accelerate. I only get this strange sound...
plus I don't hear this sound when I'm cruising or I'm at high speed..only when I'm driving less than 60 km/hr and under load (perhaps it can be resumed to: when I'm driving at a slightly high rpm, under load and accelerating,with low gear and at a low speed).

I am trying to record it better since I do get this sound longer than my previous recording and a little bit louder sometimes...

I came across an article relating to spark knock which may originate from lots of other causes...I am currently investigating this path and I hope to Find a solution soon.

(Note : else I plan to leave my car at Toyota agency in two weeks if there is no solution. I depend 100% on the car due to my erratic work requirement and long commute time- that's why I cannot easily leave the car at the agency anytime)

[Mikastef]

Btw, at the mechanic place, we also put the car in neutral and accelerate a lot. No sound was heard.

[bronsin]

Theres nothing obviously wrong GREAT! :thumbsup:

Now...GET AWAY FROM THESE CROOKS!

[Mikastef]

Thx a lot for your helpful advice. But do know that I didn't even pay a dime since inspection is free. And they advised me to go to Toyota for further inspection and repairs. So they are not necessarily crooks.

[bronsin]

Thx a lot for your helpful advice. But do know that I didn't even pay a dime since inspection is free. And they advised me to go to Toyota for further inspection and repairs. So they are not necessarily crooks.

So far so good. In spite of your lack of experience in things mechanical you havnt made a mistake. Good!

But...

If you let them take apart your transmission and engine to "find" the "problem" that would have cost you!

You are a goldfish in a shark tank. Be wary! Be careful! These people are out to make money.

Heres my advice. Take your time with this. Ive been a mechanic. Of a lot of things besides cars. The thing to do in this case is wait until it breaks or becomes worse. Or turns out to be nothing. Arrange alternate transportation in the meantime JIC.

[woops]

What you describe is either engine knocking or broken CAT

and upon hearing the recording it sounds like the air filter assembly is loose

[Mikastef]

thx Woops for your tips. But, well I am still unsure about the problem until now.

Guys, I have attached some new recordings in which you can hear the sound Much better than before !.. you will definitely hear something strange now ! Don't tell me it is nothing :)! I have compiled these recordings over several weeks of investigation.

LINK: https://www.dropbox.com/sh/n04pib5mastixcq/AABV6ppJcICPRuW3EV86o0Zba?dl=0


Note: the sound is NOT big at all - only 400 kilobytes total (so less than 1 megabyte). therefore you can safety download all four.
Thank you for listening to it and trying to help out !

[IllusionX]

If you get a chance to get under the car, do snap a picture of the joint where the cat and the exhaust manifold meet. There are 2 bolt springs are a gasket that seal the 2 parts. After 100k km, it is usually worn down and needs to be replaced.

But listening to your sound clip, it doesn't sound like a worn gasket.

[Mikastef]

Yesterday, I did the car 100,000 servicing.
I went underneath the car and look all around, changed the water pump, serpentine belt (accessory belt), use full synthetic oil, cleaned the EGR valve, changed the thermostat...
but man... this crazy sound is still here! at least I can say that it is not the water pump/egr/thermostat...
Now must continue this crazy investigation since I got the sound yesterday evening while i was driving again and it lasted for 10 second. alas my recorder wasn't with me.

[tmontague]

What year is your Yaris? I thought the Yaris didn't have an EGR valve? Not trying to hijack the thread but i'd love to know where this EGR valve is so that I can clean mine if it exists

[Mikastef]

So guys I think I'm on to something. But bad news though. Here a better sound of my problem. I have been able to record it a bit clearer https://www.dropbox.com/s/5yd2y12q7im2c8r/26%20May-Sound%20Loud.mp3?dl=0

And here is a YouTube sound which sounds similar to it https://youtu.be/S1k7ZKzXbqM


Sh*t bearing problem!! Gonna be an expensive and time consuming fix.

Anyway, the Yaris has an egr. See wit ur mechanic. For me it was not that dirty. It is below ur engine and u shud remove some parts (e. G throttle) in order to access it. Bro better go see a mechanic. But I don't think ur egr will be dirty

[tmontague]

I've had the whole intake off and have yet to see anything that resembles an EGR, I also can't find any part listed for an '08 Yaris that is an EGR. I know the d4D engines have one but I don't think. The 1NZ-FE engine does

[tdinut]

Mikastef,

I have the same sound on acceleration, never in neutral or with no load on the engine. I've had the accessory belt replaced and mentioned it to the mechanic. They don't know what it is or offer any ideas.

Has anyone figured this out? I don't want to be stranded anywhere. I have 135K miles on my 2008 Yaris and otherwise it has been perfect.

Thanks

[tdinut]

Any updates to this thread?

I have the noise under acceleration in gear but not in neutral.

[Mikastef]

Bro. Out of all these people in this forum, we are the only one having this issue.
So let's keep in touch by mail if you make any progress with it.

[tdinut]

Bro. Out of all these people in this forum, we are the only one having this issue.
So let's keep in touch by mail if you make any progress with it.

Absolutely Mika. Thank you so much. I responded and will have more info, I hope, next week.

I honestly do not think it's fatal, but I am not a mechanic. If I could only put cameras and microphones around the vehicle, it would be easier to diagnose.

I do not want to give up on my car.

Keep in touch my friend.

[tdinut]

Small update:

I just had to run a small errand. I was parked the other way around in my driveway so all I had to do to pull out was roll out into the street. I noticed that if I drove like an egg was under my foot and accelerated very, I mean very gently, I do NOT hear the noise. It's only when I need to accelerate normally or have any load on the drive train that I hear the noise. I can almost get away with not hearing it or making it audible if I have very little load on the drive train.

[tdinut]

I pretty much have it all the time now, when accelerating. It's not constant, like a clutch slips and catches, although I have an auto.

[Mikastef]

Clutch slip?...you can feel a loss of speed when you accelerate..?

[tdinut]

Clutch slip?...you can feel a loss of speed when you accelerate..?

It sounds like a clutch slipping, not that it is. I have the auto. I don't really feel any power loss but at times I'm getting a little nervous that it could turn into something more.

[tdinut]

It's fixed !!!! My car is fixed !

Definitely all exhaust manifold related. 2 parts replaced. Flange and gasket, I believe.
I can not read the mechanic's writing. I guess the flange was making the predominant metallic sound that I was hearing. Car sounds more quiet and all seems to be perfect. I will update after a day or two to make sure nothing changes. I am so relieved and happy.

[tdinut]

The exhaust gasket off the manifold might be blown out. I just changed mine because it was making noise on acceleration too. If you've never heard it before it can sound a little like you're describing.

Thanks for the tip, probably the same problem that I was having. Gasket and flange replaced, all seems perfect now.

:burnrubber: :thumbup:

[Bluevitz-rs]

Glad I could point you in the right direction.


Sent from my iPod Touch

[Rigaud]

So far so good. In spite of your lack of experience in things mechanical you havnt made a mistake. Good!

But...

If you let them take apart your transmission and engine to "find" the "problem" that would have cost you!

You are a goldfish in a shark tank. Be wary! Be careful! These people are out to make money.

Heres my advice. Take your time with this. Ive been a mechanic. Of a lot of things besides cars. The thing to do in this case is wait until it breaks or becomes worse. Or turns out to be nothing. Arrange alternate transportation in the meantime JIC.

By the way, your in the U.S. he's not and it's not the same everywhere else in the world. We get it, their crooks in your local garage and yes mostly even up here but not all of them.

[Mikastef]

Hi everyone again
Thx a lot for helping especially tdinut and Thx rigaud for taking my part.
Bronsin, your advice may be helpful and I thank you for that. However if you learned my way of thinking and my personality through all the post on this forum and even in this thread, you will learn that I'm quite investigative in nature. Check the first post on this topic. You will easily see that I have done lots lots of research. I have even listed all the potential problem that may be related to it. I have even put a microphone in my car and use a sound recorder to get the sound as raw as
possible. I have even met around four mechanic until now with no solution
You see. I'm not that stupid.

[Girishk19]

Hi Mikastef,

Me too having this problem. After 1 year. Am still in the dark. Read ur posts. Thanks guys for ur investigative work.

[Girishk19]

Ki p dire man! moi si mo ena mm probs. check to inbox. eski nou kav rente en contact?

[Girishk19]

Yes man. having the same prob for the past 2 years. have even messed up my aircon becoz of that noise. this year it became even louder. and it is stressful and tiring as i also do like 80kms per day. have tried to send u my number in inbox. seems i cant send you msgs.

[monchito18]

Bump

[monchito18]

Same issue here

[marianoI]

hi to everyone
my yaris make exactly the same noise that mikastef said he had, anyone here had the same problem and could fixed?

[tdinut]

For me, it was the exhaust manifold flange and gasket. My local mechanic replaced those two parts and the car went silent. I sold it several years later but still miss that car today.


It's fixed !!!! My car is fixed !

Definitely all exhaust manifold related. 2 parts replaced. Flange and gasket, I believe.
I can not read the mechanic's writing. I guess the flange was making the predominant metallic sound that I was hearing. Car sounds more quiet and all seems to be perfect. I will update after a day or two to make sure nothing changes. I am so relieved and happy.

[almamater]

I have the same problem on my Yaris 1.0 2006, I already changed spark plugs, etc, but we haven't found the problem. The mechanic told me now that it could be the 'anti squeak sensor' something like that, does anyone know if this exists? He even showed me in the engine where this sensor is, small connector behind the motor.

On the web I only find a camshaft sensor, is it the same thing?