Rod knock or Main bearing knock?

[yaris2010RS]

Originally Posted by jabranko

Yes it's only when the car is completely warm and the idle is between 500-700. there are 53,000 miles on it and the tranny fluid i dont believe has ever been flushed from the maintenance records i have. i just bought the car two months ago. i got an oil change and fuel injection treatment done at the dealership 2 weeks after i bought it and that's all ive done. Should I have the tranny fluid flushed?

i dont know what the maintenance milage is for tranny fluid but 53,000 i think is early. u could get it done and it will probably make the sound less or gone for a while but that is probably not the issue.

check ur engine mounts and see how much the engine moves at idle and when shifting from drive to reverse. also check the air box (mine came loose and was making a scary sound) and check hoses for contact points (probably against the firewall) and check exhaust bushings

[slow.yaris]

Originally Posted by yaris2010RS

i dont know what the maintenance milage is for tranny fluid but 53,000 i think is early. u could get it done and it will probably make the sound less or gone for a while but that is probably not the issue.

check ur engine mounts and see how much the engine moves at idle and when shifting from drive to reverse. also check the air box (mine came loose and was making a scary sound) and check hoses for contact points (probably against the firewall) and check exhaust bushings

If tranny fluid needs changing the first thing you'll notice is clunky shifting, not phantom clatters. Engine mounts will affect driving a lot.

Air box - maybe. Mine actually broke and was vibrating into itself. A new SRI fixed that. But I could hear that noise constantly pretty much, and didn't have to sound proof my garage and then hold my breath to hear it...

Seriously though if its something that quiet its probably a zip tie vibrating with the engine and hitting a coolant line or something even less dangerous...

[yaris2010RS]

Originally Posted by slow.yaris

If tranny fluid needs changing the first thing you'll notice is clunky shifting, not phantom clatters.

+1, the tranny fluid is not the issue, but at the same time, even tranny fluid with only 10,000km on it will make the engine vibrate more when in gear at idle then when not in gear.

but just keep looking for something vibriating and hitting something else.

[jambo101]

Any chance you could record the noise on your cell phone and then post it as a link?
No clue how its done but i have seen it done..

Any chance of it being part of the exhaust system doing some knocking when you come to an idle, i'd definitely give the whole system a shake as something may have come loose.

[mrbond]

lol i have this exact same problem. If you have the stock air box in place, check to see if that little snorkel is hitting the frame next to the radiator. I took off the snorkel and I haven't heard that sound again. Just a suggestion - better something cheap and stupid rather than something big and expensive.

[PROX4x4]

Originally Posted by jabranko

The noise only happens at idle goes away when the engine is revved even a bit and then comes back when it settles to a stop. But that happening only sometimes is annoying because there's no way to duplicate it other than driving the car a bit with the tech there and then stopping and listening for the sound. I've done this 3 times already and for some reason I can't get it to do it when theyre in the car. ha go figure!

Any updates? it seems like my car has the exact problem. It has 40K miles and under warranty.

[redyarisgirl]

Hi, I have an 08 Y and everything has been great up until about 10 days ago. I noticed a "high pitch" zing type noise, sort of random.. whether in Gear, Neutral, Reverse, etc. Now it has gone to a steady knocking, and yesterday for the first time, I could feel the knocking in the shifter. I have an appt with my Dealer,... who thought it might be the Alternator or Water Pump? I have been reading about the Alternator.. and doesn't seem at all what it is.... and the Water Pump.... I don't think so either (but what do I know) lol

Anyways... let the GONG begin

[Flipper_1938]

My wife's 05 corolla has made a similar noise since shortly after new. It hasn't changed in the last 150,000 miles.

[bronsin]

Originally Posted by redyarisgirl

Hi, I have an 08 Y and everything has been great up until about 10 days ago. I noticed a "high pitch" zing type noise, sort of random.. whether in Gear, Neutral, Reverse, etc. Now it has gone to a steady knocking, and yesterday for the first time, I could feel the knocking in the shifter. I have an appt with my Dealer,... who thought it might be the Alternator or Water Pump? I have been reading about the Alternator.. and doesn't seem at all what it is.... and the Water Pump.... I don't think so either (but what do I know) lol

Anyways... let the GONG begin

Have your mechanic take the alt/wp/ac drive belt off. With the engine stone run the engine and see if the noise goes away. Dont run it any longer than it takes for the cool enngine light to go out.

If the noise goes away its one of those components gone bad.

[PROX4x4]

Originally Posted by mrbond

lol i have this exact same problem. If you have the stock air box in place, check to see if that little snorkel is hitting the frame next to the radiator. I took off the snorkel and I haven't heard that sound again. Just a suggestion - better something cheap and stupid rather than something big and expensive.

Mine was exactly the same problem and as you said I just super glued that little thing in it's slot and haven't heard the noise again.