I have a 2005 5AT and when I have it in sport shift, I hear a knock when pushing the car hard. When in 2nd gear, I'll get the rpm's up to about 6000 then shift into 3rd, and I will hear a knock in the engine. It shifts fine but the noise worries me a bit. Anyone have any ideas as to what this is? Anyone else experience it?

 

Are you running 91 octane gas
Not E85 or other Ethanol blends-bad

May be time for a fuel system/injector clean out
Save 90 bucks and DIY see gen2 Seafoamed the ol TL

 

I'm running 93 Octane, I only have 28500 miles and have put 89 octane in my engine one time since I've owned it.

 

with approx 30k you are ready for the fuel injection cleaner service
Seafoam is the same product used by shops- they just add it to a gallon of gas and tap into the injector loop and chage 100 bucks.

Its possible with winter fuel blends and possible water getting in storage tanks that contamination happened. Many of us get worse mileage and performance in winter

Seafoam will also pick up any water that may be in there as well as everything else it does

Thats my suggestion

 

I have 27.8K and seafoamed a few days back. Put in gas and oil. I was not sure of a vacum line so i did not put in vacum line. Overall it really didn't blow any smoke, just a smell of running rich from the exaust. I think it has help performance slightly, but in my opinion, it should be done with higher milage due to 93 octane gas being used

 

I’ve had the same knock on a couple of occasions while getting on it. It’s not an engine ping or an injector issue. (I first noticed @ 2,000 miles) It’s definitely a mechanical knock.

 

Agreed! I am going to bring it up to the dealership when I go for my 30000 mile maintenance. I don't always drive like an ass, but its fun every so often, and it worries me that it might be bad for the engine. This definitely shouldn't happen.

 

i have this problem as well in my 05 5AT and i always thought it was my Injen Intake tube knocking on the metal whole it goes through (like a bolt came loose). everyone else seems to be describing an internal engine issue. so correct me if im wrong but what i get out of what your saying is like something knocking around inside the engine compartment? if so im interested to hear more and see if we have a similar issue. this is only when im flooring it between 1st and 2nd though. to me it feels like engine recoil from the torque slaps the engine or exhaust or intake tube into the firewall or some body part.

 

Torque slap, as you are calling it, would make sense, but any movement should be dampened. Thats why it worries me. This happens basically when I am flooring it as well, and I notice it particularly when getting on an onramp to a highway, from 2nd gear, shifting to 3rd, when messing around and pushing the car hard. It is not extremely loud, but I notice it, and it shouldn't be there. My music has to be down, but it is metal to metal it seems, a thud or knock noise.

 

oh yeah totally a thud noise. i think it could be part of the exhaust hitting the underbody when the motor is flexing its v-tec and then yeah the shift settles it back down but with a whip or a slap back into place. but i do agree with the dampened movement, maybe the thud is coming from a loose exhaust mount or motor mount or tranny mount. i have about 37k on my car and didnt notice it until about 25-27k and rarely happens, just when im flooring it hard and shift.

 

just a thought, but could it be the motor hitting the rev limiter when the gears are changed because with already high RPMs and the transmission diengaging to switch gears, it might happen. Just my on this.

 

Not sure, I only notice it when pushing the car and shifting when at high rpm's. At any rate, we need to check back and update eachother once we discuss with the dealership. I'll be bringing mine in, in about a month or so for the 30,000 mile maintenance.

 

I also have a stock 05 TL 5AT with ~25K miles and the same sound. I hear it in auto or SS modes and only during the shift from 2nd to 3rd at full throttle. It is definately a thud sound and I believe it is most likely the larger engine and torque working against the engine mounts. I would not say they are worn out but they maybe wearing (this accounts for the sound around 25K miles) or possibly not stiff enough from the factory (explains the sound at 2K miles).

It could be many different pieces bumping into each other: exhaust with the underbody, engine with the hood, intake with the engine bay or possibly the mounts themselves.

I will have them check it out at the next service. I also plan to swith to amsoil synthetic oil and ATF (the only atf designed for honda transmissions).

 

HI
I am obviously new to this forum and have recently purchased a 2006 base tl and have noticed this same noise only twice so far.. both times it was from a left hand turn and a hard accel from 2nd to 3rd also, exactly as described by noah419 at first I thought it was a backfire because I had my music on and barely heard it . the second time was more noticeable with the windows down and sounded more like a knock from the passenger front side somewhere ... any answers yet ?? Thanks