Hey all,
I own a 2005 Acura TL 6MT. All is good with it except for this ongoing grinding noise while the car is under acceleration. Every time I have taken it in to the shop the Tech's cannot reproduce the sound, but I think it's pretty apparent. Anyways, I managed to attach a go pro to the subframe and managed to capture the sound on camera. WIN...sort of lol. Anyways I attached the video below. You can hear it throughout the video if you listen closely, but it is VERY apparent at around :50 seconds when you can hear me stop and start again. Please give me suggestions on what it can be. I won't be able to get to the shop soon because of school, but would like to know if this is super urgent. Thank you all so much.
-Chase Howard

-Link to the video

 

So I actually had the same exact noise on my 05 AT TWICE!. I honestly can't tell you the exact bolt, but can point you to the general location.

My buddy put it on a lift and I was in the car with the E brake down and held the foot brake down while hitting the accelerator. This same noise only happened to me when accelerating and around 1200-1500 RPM.

It's on the passenger side and through the exoframe. Past the steering rack. You can't get to it from the top. He had to use a 12 inch extender and a 10mm socket. Bolt was holding a bracket. I can say that it's the only gap you can look through deep enough into the engine bay, if that makes sense. The second time around, we put thread lock and hasn't made the noise since. I guess vibrations are enough to shake that one specific bolt loose all the time. It was nothing you can see or point out just by looking at it with the car off. We literally had to get the engine going to replicate the noise while stomping on the brake 6 ft in the air.

Hope this helps.

 

At 55-56 seconds all I hear is the rattle from the exhaust which is either a loose heat shield, a broken flex on the J-pipe, bad motor mounts which allow excess vibration through the exhaust system and or pinging due to wrong bad quality or wrong octane gasoline. Check and inspect the exhaust system followed by the motor mounts.

 

I just ask my buddy what that bolt was holding and he did correct me and say it was a heat shield. Perfect timing on posting this!

 

Usually always a heat shield, especially 1,000-2,000 rpms
If it's the 3rd cat I simply remove the shield that's loose. The 2 primary cats get a hose clamp if they act up.
Check the engine mounts as well, they can be worn and send vibrations out.

 

Appreciate it man. I’ll have to get under the car this weekend and check some things out. Definitely not pinging from the wrong octane, always always use 91.

 

I use wromg octane all the time and no pinging. They work on any octane pretty much... But yeah heat shield is my guess too

 

Pinging isn't always easy to hear, but its highly possible. The TL is required to use premium gasoline. It as simple as reading the inside of your gas lid. Other factors like location, driving conditions and weather plays a huge roll. If you're in Washington state compared to Florida, best believe you have a better chance of running 87 better than the the person in Florida running 87. Yes, heat shield is the most likely problem. It doesn't mean that he may have another issue as well. The 2010-13 MDX were notorious for pinging. The TL is also known to knock in the high summer temp, more prone to knock when using less than the required fuel. I'll stop here so this doesn't become into another "fuel" thread. OP, keep us posted.

 

 

Car is finally in the shop diagnosing the issue. Luckily I was able to take a tech out with me and he was able to hear the noise himself a week ago and I got the car in today. I’ll let you know what the issue is when they figure it out!

 

@Chase Howard Yo was it the bolt on the heat shield? Anyone know? I just bought 05 TL and having the same issue

 

Hey man! I’m fairly convinced mine is from the transmission to be honest. I’ve had the noise since I bought it about 40,000 miles ago and it hasn’t been a serious issue. My ‘05 just seems to be falling apart at this point...it is my college beater after all. I’m hoping to upgrade to a Fiesta ST pretty soon! Hope you can locate the noise...heat shield is definitely a good place to start.

 

EVERY problem is different.
You will need to use "visual intelligence" or the act of looking for clues.

you will need to look at the heat shield and if it looks rotten and falling apart, you can bet your bottom dollar that it is the heat shield...
if the heat shield doesnt look corroded and is not falling off, then it may not be the heat shield.

Visual Intelligence is key for diagnosing and repairing anything in life.