Hi, I recently bought a TSX (AT) and have noticed this noise ever since. It usually happens the first time I use it after it's been sitting idle for a while (typically 1st thing in the morning). I put the car in drive from park/reverse, barely hit the accelerator and then I would hear a thud/bump noise, which sounds like it's coming from underneath my brake/accel area. The sound then goes away the rest of the drive. I've read in the past threads that the sound is probably due to the ABS system calibrating itself, but I just wanted to be sure and had some questions. Is it "normal" for the ABS to make such a noise when it's self-calibrating? Do all cars with ABS have the same issue? Is there anyone out there who doesn't have this issue? (To test for this noise, try driving the car first thing in the morning (Radio turned off) barely touching the accel in the beginning and listening for the noise. Sometimes the thud is very noticeable.) Is there any way to "fix" this issue? I'm hoping that there's a solution to this problem.

 

[QUOTE]Originally posted by tsx21
Hi, I recently bought a TSX (AT) and have noticed this noise ever since. It usually happens the first time I use it after it's been sitting idle for a while (typically 1st thing in the morning). I put the car in drive from park/reverse, barely hit the accelerator and then I would hear a thud/bump noise, which sounds like it's coming from underneath my brake/accel area. The sound then goes away the rest of the drive. I've read in the past threads that the sound is probably due to the ABS system calibrating itself, but I just wanted to be sure and had some questions. Is it "normal" for the ABS to make such a noise when it's self-calibrating? Do all cars with ABS have the same issue? Is there anyone out there who doesn't have this issue? (To test for this noise, try driving the car first thing in the morning (Radio turned off) barely touching the accel in the beginning and listening for the noise. Sometimes the thud is very noticeable.) Is there any way to "fix" this issue? I'm hoping that there's a solution to this problem. [/QUOTE

I'd say its normal.

I've heard its a Honda thing specifically but I know the exact noise you are talking about. Its like a thunk you can feel under the brake pedal or as you drive off.

 

I think we've concluded that it is the ABS priming itself, a function that was implimented as a result of the original ABS system ont the Legend - when the system wasnt used for a long time, the pumps apparently were at risk of not functioning. As a result, new acura's prime the pumps each time the car is started to ensure that the ABS system will be able to function normally when it is needed after a long period of time of unuse.

J.

 

I think you are normal mine does it as well. To be exact, with the 6MT it does this after the car has been sitting for a while and it happens exactly at 2K rpms for me.

 

does it happen after you reverse then drive in 1st gear? i think i hear a similar thud only after i reverse then drive at around 2k rpm. just reassuring to know that someone else has this problem.

 

get the same sound when I take off in the morning.

 

Yes it usually happens when i reverse out, then start driving. I never noticed if it matters whether i reverse first or not...

 

I don't think the thunking noise is RPM dependent; it's speed dependent. What speed are you going at 2K rpm in 1st gear?

 

yeah... i just put 2k rpm before b/c it sounded right... but now that i think about it... its not when i'm going that fast (1st gear, 2k rpm = ~10mph?!). it happens more around 5mph in 1st gear. but i only notice it when i start driving off after i reverse out.

 

Yes, I also notice this initial thump noise, which the consensus shows as normal. Also had the same phenomenon in my previous Accord V6, but it was more of a buzzing noise rather than thumping.

 

Thanks for all the replies. To answer some of the questions above: 1) It happens regardless whether or not I put it in reverse first. 2) It's not RPM dependent. It happens regardless of the RPM or speed. It's just that at slower speeds. you're able to hear the noise better without the engine/revving noise getting in the way. Still, does anyone know if this is "normal" for ABS systems? I've never heard of any other cars with ABS that has this problem. It also doesn't make sense when the ABS does recalibrate itself, why it has to make this noise. And, if it's pumping the brake or something as suggested in an earlier thread, why would it be doing it sometimes while I'm pushing on the gas?

 

If it happens once it's probally ABS. If you notice it at slow speeds more than once after stopping then you could have the same problem I had. The front sub-frame assy was loose. The dealer retorqued the sub frame and suspension components. My noise is now gone.

 

Glad someone else noticed this thumping noice too. It was starting to get on my nerves only cause it is consistent and you know when its going to happen. Like everyone else, just starting up the car and making that first few feet of driving at slow acceleration. For me, I'm usually backing up first and then once I go forward......clunk...........then pure silence : ) (except for my brakes which still squeal a little but not as bad as a few weeks ago).

 

Yea i recently heard this noise too after i start the car........ i think when i let the car roll down the hill without touchin the gas pedal i didnt hear the noise..... but definately heard it a couple of times!

 

Yeah.. It happens to my TSX too. Guess it is a normal sound when starting after a long rest.

 

I thought u guys were talking about the thud when u start the car, by the way, another experience a engine knocking sound when u start the car? is that normal?

 

the only weird ENGINE sounds that i've gotten so far .... mind u the car is only about a week old since i've gotten it, sometimes it takes an extra second or 2 to start..... like u turn the ignition and then it kicks in..... but there were instances where i had to HOLD the KEY a couple of seconds longer than usual until it started and the RPM flew up to 2 RPM with a LOUDER than usual engine start. But that really doesnt worry me much yet...... hopefully it was just a cold engine start and needed to warm up????

 

great i was going to ask my dealer but the sound doesn't appear often, i dunno if they will believe me or not

 

Yup, I have that too!

On the 6MT

 

Mine is a 6MT too, there is an engine knocking sound when it starts. I get bad start when I first got the car but it seems normal now, but the starter was kinda disappointing, the RSX starts nicer without even need to hold the key on the ignition as long as I need on the TSX.

 

does the thud ever happen when ur in 2nd gear on the 6speed. i think sometimes it happens to me in second gear too.

 

mine only happens during startup

 

I have a Optima Yellow top on another of my cars, I think I will try that battery on the TSX and see if it helps it start faster. Pray it is not the starter, because I don't want to change something that major out.

 

A Yellow Top? I thought those were only deep cycle: http://www.optimabatteries.com/produ...ycle/index.asp

I had this (sorta rare) Orange Top in my Camry, but most people have the Red Top Starters: http://www.optimabatteries.com/produ...rter/index.asp

Did it work?

 

I bought my TSX in July 2003 and thank God I found this site because I'm getting the same thud noise after I star my car on the morning and let me tell you althougt it seems to be normal it's very annoying. I personalle hate to hear noises on my brand new car that gets into my nerves.

 

Mine sounds like it is getting quieter....that or I have gotten used to it

 

The sound is your ABS solenoid. It is in fact normal. I got it on my old TL, My 04 TL has it, my RSX had it and my TSX has it. I even got it on my Toyota truck. It's not a problem just get used to it. When the car is dead cold and the power assist builds up the pressure on the brake system right after the car starts the solenoid clicks to equalize the pressure in the ABS module. Really, it is nothing to worry over.

D.