Jonathan Matczak

I have a 2011 shawd 5spd Auto same noise everyone is describing in this thread. Hope one of us figures out what's really causing it.

mrphilipanderson

Okay Guys, im back with an update. I wanted to give the car a few more miles before I made my final conclusion about the Hypiod Fluid (Tranfer Case Fluid) chang made a difference or not.

OVER all, absolutely yes. In more ways that i expected.
Drive-train became more...linear...solid and shifts became smooth.
The driving profile of my car changed. Improved, if you will.

The next change i noticed was how that rattle sounded after. It was shorter and quieter.
Over time it changed some loud, some short.... As time passes, it happens less and less.

Yesterday it didn't do it AT ALL. not even once. I marveled over that.
Previously I mentioned adding fuel octane booster also made a difference.
Heres my crazy theory...

The transfer case is under most pressure during acceleration.
something in the fluids viscosity changes when we stop for gas or toe go in store and come back
and drive the car. My car NEVER does this noise on a cold start. EVER. ALWAYS after an initial drive, i shut the car off to run an errand, and its the NEXT drive
that makes the noise. So I imagine the thicker the oil the quieter the crack in the Transfer case? Im sure some expert will chime in and tell me how dumb I am, but this is just my hypothesis. LOL

Because Ive had my ENGINE and TRANSMISSION replaced guys. TWICE. So its not those components. Im certain.
The noise remained through out all or at least returned unchanged. I honestly think its the Transfer case.

Its 80Bux. What could it hurt. Get it changed and just try. It seems to be impriving the more the car is driven.
One guy says he changes his Transfer case fluid, Transmission fluid and Rear Differential every 30k. I think Im gonna start.

Because when this car drives like it should, its like the high of a drug. I just wanna drive All day.

mrphilipanderson

I love your last name. Fun to say.

Viscidity

I have had this problem for about the 6 years that I have owned this car. I have finally figured it out and it is actually the heatshield that sits above the jpipe. Apparently it's pretty up there and that I would need 3-4 hours for someone to get to it to fix it. I haven't gone ahead and done the fix yet but that's what the exhaust shop guy has found out. I've been going to this guy and getting things changed here and there for this whole year now and we have got it down to this spot.

mrphilipanderson

Weve all thought it was this at one time or another, Please do make the fix and get back to us. I certainly hope it works for you.
It has been diagnosed as:

Piston Slap (due to falty o-rings)
Heat Shield (on Cat Converter)
Muffler rattle
Octane Knock Sound...

And each of these fixes hasnt worked.

And yes guys, after a few thousand miles after my Hypoid fluid change...The rattle is back.
Whatever it is, no one an I mean NO One can figure it out.

TLTesh604

I find this hard to believe, but is there any update with your car? Would actually be great to know it’s not something engine component related. My car’s rattling has been the worst in its life these past two months. Wondering if it was the winter gas mixture or not. I feel that the car does the slightest hesitation upon initial acceleration when the rattle happens. Thus, making me think it was engine related. I still love this car but a couple noises I’m having along with oil burning is making me want to dump before something big happens. It’s been a relatively care free 10 years with it.

mrphilipanderson

same. I thought i had it fixed...it came back.
IVe tried everything. The only thing I havent tried is replacing the short block. Cause many mechanics keeps saying piton slap.hopefully this oil consupmtion crap will fx it. I have sucha love hate relationship.

Viscidity

Im currently awaiting the parts for the new shortblock and engine rebuild due to the oil consumption. Apparently my car was burning 1L/700 km of oil LMAO. I told acura to change the j pipe area heat shield and check the rattle while they r doing the engine repair. Hopefully this gets rid of the problem as I also have a big love / hate relationship with this car as well. First crowsfeet all over car paint, rattling ever since i owned and now this lmao

mrphilipanderson

Any word on the rattle since the repair? Im like dying to know. There are so many of us that have this issue. I am doing my oil consumption test TODAY.

mrphilipanderson

Take it in, do the Oil Consumption test. Even thoug Ive had all thiese issues with my c ar I still love it like a lover. Its freakin sexy. Its powerful. Its innovative.

ecwbum

I’m also having somewhat of a similar issue. When I drive normally and not accelerate hard (pushing down on the gas pedal) it drives normal. No rattling noise or anything. But when I give it some good acceleration I’ll hear the rattling noise for a split second and it’ll disappear. The noise sounds like it’s coming from the front area. When I rev my engine, I do not hear the rattling noise as well if that helps.

Anyone know what what the issue would be? I’m seeing a lot of people saying it is the heat shield?

Edward'TLS

^^^^^

This is called engine knocking or engine pinging. The gas/fuel mixture inside the engine cylinders is detonating prematurely.

mrphilipanderson

Okay everyone...after consulting with a few who go the Oil consumption issue fixed, the knock went away also!.
It was explained to me as "Piston slap". See link https://mechanics.stackexchange.com/...ton-slap/39515

After hearing this and reading this paring with the oil consumption...Oil doesn't it back down so for those few seconds when oil is not on the cylinder wall it makes this Rattle sound on acceleration. Once the cylinder wall gets lubed up again it goes away.
A mechanic told me this a very long time ago, but I didn't want to believe it since id gotten a valve adjustment. Also, those who have gotten the repair done says its like a different car altogether. WAY more responsive, more quiet...see link: https://acurazine.com/forums/fourth-.../#post16409101

I once had an acura Master tech tell me
"Its just what the car does under load"...WTF. Well guys I think we have found the culprit. And it makes perfect sense. Chime with your thoughts....please. I am curretly on my oil consumption test. My dealership told me to come back after 1500 miles. Not 1000. They didnt overfilll it either. it was Exactly where the oil reading should be after a change.
Some dealerships arent honest. If you want to make your car drink oil to fail the text drive it harshly...flooring it....that always seems to make mine DRINK oil.

Edward'TLS

My Acura dealership has confirmed that a PCM software update can fix this "engine-noise-when-stepping-on-the-gas-with-a-warmed-up-engine-during-initial-startup" issue, but unfortunately this rattle noise will come back after a few months, possibly due to the difference in formulation and in volativity between summer and winter gas.

mrphilipanderson

This issue goes away when you change rear differential fluid, but it comes back
This Issue goes away when you put Seafoam Fuel Cleaner, but it comes back...

None of these are fixes if the sound returns. I am clinging to the idea that its "piston slap:" as a result of faulty O-rings causing oil to go places its not supposed to be and losing oil where it should be (like the cylinder wall) due to the 0-rings collecting carbon deposits and malfunctioning.
I wont know until I finish the Oil Consumption repair on my own vehicle. But many have reported the rattle is gone after such repairs....only time will tell if it returns.This rattle is heard throughout every state in the US and Canada...I seriously doubt its fuel related.

Edward'TLS

In my case, the rattle noise comes and goes even if I don't do anything, and happens more frequently in the cold winter days.

Mine is definitely fuel related, because I have also experimented with different gas brand, with Chevron gas giving the least occurrence of "engine-noise-when-stepping-on-the-gas-with-a-warmed-up-engine-during-initial-startup", and PetroCanada gas that guarantees a 90% occurrence rate.

mrphilipanderson

are you going to get the software update you mentioned to fix it? or does it not bother you enough?

Edward'TLS

^^^^^

No. Because even my service adviser advised against me doing the software update, due to (1) the update operation cost money, and (2) the rattle noise will come back again after a couple months according to their customers' feedback and of course complaints.

Edward'TLS

Not worthwhile wasting $$ on a temp fix that only lasts for a couple months.

Cho-Cho Susi

I found what’s causing this issue. I used to be a Honda ASE mechanic and I recently bought a used 2011 MDX. I noticed a rattling sound when accelerating when I had the window down. I initially thought it’s my drive belt tensioner but after replacing it the noise is still there. I did a further troubleshooting and found it’s my A/C compressor. Replaced the whole unit the noise is gone. Give this a try. Might save you guys money.

mrphilipanderson

it is advisable to give it 30 days before calling it a permanent fix. We've all for year have been thinking we've found a solution. Has it been 30 days yet since you're rattle free?

Cho-Cho Susi

Yes. It’s been over 30 days. If your MDX is making a metal grinding noise when accelerating from 1-2nd gear. Like I said if you’ve had your drive belt tensioner replaced . Try having your mechanic use a microphone to pin point the noise. We use these special Honda microphones to clip on parts of the vehicle to trace rattles or noise.

mrphilipanderson

I’m not sure the noise you heard is the same as the one this thread is built on. Refer to the various videos and descriptions as to when the rattle happens etc. I’m just a skeptic about a fix at this point. But it sounds like an entirely different noise that u mention ( in my personal opinion). Would be nice if it were a fix.

samardeep aujla

Did you find solution??

samardeep aujla

What they end upto

LOGONZOJLS

this fixed my issue. Not hard to do either! Remove the Y pipe and you will see a bracket right there, easy access, tighten w locktite blue and you should be good to go.

2007 Acura MDX

mrphilipanderson

IF YOU HAVENT yet, CHECK OUT THE OIL CONSUMPTION THREAD ASAP. You may be able to get help.

Lynnedita

I've read through this entire chain and found it very helpful. One of the videos is making the EXACT noise that my engine makes but the poster said it was a catalytic converter. I've had my MDX for less than two months and OF COURSE noticed this noise a few days after originally purchasing the used vehicle. I BOUGHT this car because my Lexus needed a new catalytic converter and no shop would take on the task of replacing it without charging me $4K! What are the odds that I have ANOTHER car that needs a catalytic converter?!!!!
I'm taking it to the dealership on Tuesday to have them look at it. I just don't want them to write me off because I'm a girl and tell me I'm hearing things. CLEARLY I'm not the only person who's been dealing with this but if I go in with a list of ideas that you came up with are they also just going to get annoyed with me.
UGH. I BOUGHT A NEWER CAR SO I WOULDN'T HAVE TO DEAL WITH THIS. Not even two months in and my car is already in the shop. UGH

On a side note, does anyone else's car kinda "auto-brake" when in traffic the second you let off the gas? I feel like I'm going to make myself car sick with the way it drives. I HATE it. On my test drive I was not in any sort of traffic. Had I experienced this auto braking crap I would've NOT bought this car. I have TOTAL buyer's remorse right now and I have a six year loan..UGH.

mrphilipanderson

Problem solved. I think for sure THIS TIME. I got a letter from Acura about high oil consumption.
For 2009 - 2014 TL SH-AWD MODELS and MDX with the 3.7 ENGINE. NOTICE EVERYONE OF US IN HERE DRIVES ONES OF THESE TWO CARS, WITH THIS VERSION ENGINE.
Mentioned Carbon build up on the pistons, etc yaddah, yaddah. Brought it in for testing, it failed.
The fix is covered at no cost to you, under warranty UNTIL SEPTEMBER 2019! I took it in,
Drives like a new car. Makes not a single noise. Its been 600 miles, not rattle whatsoever.
As a matter of fact, every noise that bothered me about the engine seems to have been fixed by this.

It was told to me that Acura Has updated the parts such as Pistons, Rings, Bearings, etc. As there parts exclusively on the 3.7 engines proved faulty.
High oil consumption being one of them...Piston Slap being another. I believe what I was hearing was piston slap. Everyone that I know of that Got this Warranty repaiir done on their 3.7, their rattle have gone.
For me its only 600 miles, and I cant be 1000% sure until a couple thousand miles. But still...if you guys havent done the test and got the fix DO IT. Acura is giving us a HUGE courtesy to get the short block of our engines rebuilt essentially.
Thats Outstanding brand maintenance in my opinion.

mrphilipanderson

There are two ways to turn off Autobreak. One is in the MID(multi-Information Display) menus beyond the steering wheel or there's a button near your right knee by the steering wheel to turn off.

Lynnedita

Hi Mr. Philipanderson. Thanks for the update on how to turn off Autobreak which is the MOST ANNOYING FEATURE EVER!!! Also, thanks for your recent post about what [hopefully] worked to fix your engine rattling. My car is STILL at the dealership (going on a full week now) and they were able to do a software update to fix my slipping transmission but have told me on several occasions that the engine rattling is not happening and told me to come pick up my car. I informed them that if I drove it off the lot and heard the engine rattle (which they clearly have not fixed because they "can't hear it") that I would turn right back around and leave it with them until they fixed it. I told them to schedule a test drive with one of their mechanics so they can hear what I hear. I'm going to tell them about what you said about high oil consumption and make them look into that. The engine rattling makes me HATE this car. I've been test driving a 2018 MDX which has NO engine rattling noise and love it. I really hope they are able to fix my car.

mrphilipanderson

The fix is for HIGH OIL CONSUMPTION...and the side effect of that fix is the rattle is fixed also. As i understand it, Anything more than 1qt/1000Miles is NOT normal and could qualify you for the fix.
YOUR CAR IS ON THE LIST if you have he 3.7 version and you drive an MDX. Google " High Oil Consumption For MDX" and it should come up.

You have to drive the car around 1000-1500 miles and if it consumes more than 1quart of oil you should be good for the repair. AT NO COST TO YOU, covered by a newly extended warranty to TL and MDX owners that suffer from high oil consumption.

dregsfan

Autobreak? What the hell is that?

mrphilipanderson

1000 miles and more than 100 starts and shut off after my HIGH OIL CONSUMPTION repair done under warranty, and not a SINGLE RATTLE OR GARGLE.
This problem of this thread seems to be history. get it done guys BEFORE SEPT or youll have to learn to live with the rattle.

mrphilipanderson

its where the car slams on the breaks for you (collision mitigation)

mrphilipanderson

DID YOU GET YOUR OIL CONSUMPTION TEST DONE? it will take care of the rattle.

dregsfan

In a 4G TL??? What trim level has that? Or was the poster talking about a TLX?

mrphilipanderson

This goes for anyone that for the letter. There are mdx and told across the nation getting this done. My car is a 2012 TL and advance. Every 3.7 Acura engine from 2009 - 2014 has this issue.

mrphilipanderson

BUMP. Please get the oil consumption test done. It inDIRECTLY fixes the piston slap all us 3.7 owners have. DO IT DO IT DO IT!

mrphilipanderson

The poster was talking about a different model I just understood and answered. She was speaking on an MDX if im not mistaken. Same engine though.