Cold start knock = Anti-lock Brake pump???

[2011RedSE]

I have noticed this sound for a while but havent had time to take it to the dealership. From a cold start, when you put the car in drive, there is a brief knock that comes from the front of the car. This only happens when you start to drive off. The intensity of the sound varies by day. Some days its quite loud and others its barely noticable. Interestingly though, the sound only happens after you put the car in drive. I back out of my driveway and it doesnt actually occur till I swap from R to drive and pull away. I called the dealership to schedule my first oil change and mentioned it and that i found a TSB that sounds pretty spot on to what is happening. The service tech told me he knows the TSB i am referring to, that the sound i am hearing has nothing to do with the TSB and that it has to do with the Anti-Lock brake pump initializing. He stated that this is just how these cars are. Now this sounds like a bunch of horse crap but then again i know nothing about brake pumps. I would think the brake pump would initialize the moment the car starts moving and not only when the car is put in drive.

Any thoughts? Has anyone else recognized this sound or had a similar problem?? I wanna be able to tell this guy he is full of crap if in fact he is.


Njerald posted the below TSB back in december and i think this is the actual problem.

T-SB-0146-10, Brief Engine Knock/Rattle Noise at Cold Startup, dtd. 6/910

2010 – 2011 Camry Engine(s): 2AR Transmission(s): 6MT, 6AT

2009 – 2010 Highlander Engine(s): 1AR Transmission(s): 6AT

2009 – 2010 RAV4 Engine(s): 2AR Transmission(s): 4AT

2009 – 2010 Venza Engine(s): 1AR Transmission(s): 6AT

Immediately following a cold soak startup, some 2009 – 2011 model year vehicles equipped with the 1AR-FE and 2AR-FE engines may exhibit a brief knock/rattle noise from the engine compartment for

approximately one second. Follow the repair procedure below to address this condition.

3.5 Hours to replace camshaft timing gears,,

[JackTheRipper87]

I've had the same exact knock since the day I bought my 2008 Camry LE. It happens exactly the way you described it. I can't remember where I read this, but I thought it was the ABS "self test" kicking in. I've been driving my car for 3 years now, no issues with ABS, brakes, or anything really. I don't think you need to worry.

Someone correct me if I'm wrong.

[Luna2]

Originally Posted by 2011RedSE

I have noticed this sound for a while but havent had time to take it to the dealership. From a cold start, when you put the car in drive, there is a brief knock that comes from the front of the car. This only happens when you start to drive off. The intensity of the sound varies by day. Some days its quite loud and others its barely noticable. Interestingly though, the sound only happens after you put the car in drive. I back out of my driveway and it doesnt actually occur till I swap from R to drive and pull away. I called the dealership to schedule my first oil change and mentioned it and that i found a TSB that sounds pretty spot on to what is happening. The service tech told me he knows the TSB i am referring to, that the sound i am hearing has nothing to do with the TSB and that it has to do with the Anti-Lock brake pump initializing. He stated that this is just how these cars are. Now this sounds like a bunch of horse crap but then again i know nothing about brake pumps. I would think the brake pump would initialize the moment the car starts moving and not only when the car is put in drive.

Any thoughts? Has anyone else recognized this sound or had a similar problem?? I wanna be able to tell this guy he is full of crap if in fact he is.


Njerald posted the below TSB back in december and i think this is the actual problem.

T-SB-0146-10, Brief Engine Knock/Rattle Noise at Cold Startup, dtd. 6/910

2010 – 2011 Camry Engine(s): 2AR Transmission(s): 6MT, 6AT

2009 – 2010 Highlander Engine(s): 1AR Transmission(s): 6AT

2009 – 2010 RAV4 Engine(s): 2AR Transmission(s): 4AT

2009 – 2010 Venza Engine(s): 1AR Transmission(s): 6AT

Immediately following a cold soak startup, some 2009 – 2011 model year vehicles equipped with the 1AR-FE and 2AR-FE engines may exhibit a brief knock/rattle noise from the engine compartment for

approximately one second. Follow the repair procedure below to address this condition.

3.5 Hours to replace camshaft timing gears,,

I hear the ABS after each start up during the first forward motion at about 9mph. It is normal.

Page 147 from the 2011 owners manual...

"Sounds and vibrations caused by ABS, brake assist, VSC and TRAC

A sound may be heard from the engine compartment when the engine is started or just after the vehicle begins to move. This sound does not indicate that a malfunction has occurred in any of these systems.

Any of the following conditions may occur when the above systems are operating. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after ABS is activated.
• The brake pedal may move down slightly after ABS is activated."

[Donald E. George]

My 2004 Camry does the same thing.Regards

[2011RedSE]

Thanks everyone for their input. I had a 2008 LE and never heard this noise. I saw the part in the manual as pointed out but the knock varied in volume. Sometimes it is a really loud and grinding thunk and others its barely noticable.

I took it too the dealership today and they said it is the Camshaft gears and are going to replace them as part of this TSB. They said the sound i was hearing was too loud to be the AntiLock brake initialization

[Ryan_V]

does it sound like the knock/tap in the video in my signature?