Engine Rattle when Traction battery low

I wonder if that noise could be coming from a worn out drive clutch plate that couples the engine to the transaxle. It has springs and a clutch disk to smooth out power pulses.

 

Does the OP have their a/c on high at the same time? There are reports going back a while where if the a/c is on full and the battery is on 2/8 bars, then the car vibrates/drones a little more than usual with some reporting vibration through the brake pedal. I believe the consensus was that it was normal with the engine working hard to power both the a/c (about 4kw) and charge the low battery.

 

Did you ever figure this out? I have same issue

XT1254 ?

 

I purchased my 2010 used with 90k mi and I realized it doing this after a week. Seller convinced me it was engine knock and thought like you maybe after maintenance it may go away. Now at 130k, all maintenance done, same thing. It seems on a fresh oil change of Mobil 1 it seems to not knock (whatever it is) as much until 2k or more mi. For fear of it being something serious, I now try to just let car sit when it has 2 bars until it finishes charging. I checked for recalls and nothing shows for my VIN have you checked yours?

XT1254 ?

 

So quick solution for me was higher octane. I had tried putting in higher octane gas before and was still getting the rattle pinging sound whenever the conditions in this thread were met. Yesterday however, I bought a can of high octane booster and used it to treat the last 3 gallons in my tank. Recreated as many conditions I could in the next 80 miles and could not recreate the pinging/rattling condition. Just prior to this at a full tank, I put in fuel injector cleaner which actually made it ping worse. So bottom line if you are trying to rule out this condition, make sure you get about 100 octane to test the theory. Until I solve this I guess I put 92 octane and bump it with
octane booster if needed. At least now I know what I am dealing with so off to another taptalk thread for me. Hope this helps someone out there.

XT1254 ?

 

Maybe the pinging is due to increased compression, due in turn to carbon build-up at top of cylinder head.

 

... or maybe a problem in the EGR system?

 

^ Did you clean EGR gunk from intake manifold as well? Was cleaning needed? How many miles when you did that cleaning?

Seems a design fault, that it it gets so clogged.

 

I "liked" your post, but I don't like it. Toyota screwed up here.

 

Ever figure out what the noise was? I have the same thing.

 

I am wondering if there is some type of "knock" sensor attached to the engine. In other vehicles this sensor is monitored by the vehicle computer to send a signal when it detects a knock, which the computer uses to retard the timing dynamically until there is no knock but maximum timing advance.

 

Every modern car has a knock sensor. I guess it can malfunction, but that should generate a code.

 

My check engine light came on and i took it to Orileys to have it diagnosed and their equipment was faulty and check engine light is off now. Thanks Orileys. I was able to get a recording,

 

My car is doing the exact same thing. If anyone has figured this out, I would really appreciate the advice. It only does it when the battery is on 2 or 3 bars. Also I have noticed that it will not make this noise if the engine hasn't warmed up. Any success stories out there?

 

I just want to say I have this too, only when the engine is charging battery (2 bars) and it's going around 5-10mph and the noise goes away afterward.

The car run great, just don't know what is causing this noise.