2006 Highlander Hybrid Limited 77k miles. The last month or so. I have been hearing this knock,tap type noise when at idle. It mostly does it when in reverse or in neutral. if you stick your in the driverside wheel well you can really hear it better. Sounds as if it may be from the front CVT/Motor. The sound is not consistent or have a rhythmical pattern like a rod knock. Its sporadic, and will go away sometimes after being driven. I think it really only does it when the gas engine is running. I have seen a recall issued that does not include my vehicle, but is in this model year with the 3MZ-FE motor. about the harmonic balancer coming apart and causing a noise. I have not checked this yet on my vehicle, but will when i get home.

 

alright so today it would only make the noise in neutral. If i grab the left cv axle you can definitely feel the knock/tap/vibration. Think it just may be time to trade this thing in. lol

 

That doesn't sound good, I would want to get to the bottom of that issue asap.
You can try a mechanic's stethoscope to help pinpoint where the noise is loudest and start from there.

Also any codes stored in the ECM?

 

yea, I have a stethoscope at work. There is never a variance in the loudness of the noise. Like i said it never does while driving. I have a zero in difference in drivability. It only makes the noise after the ICE starts up then after about 30 seconds when the ICE goes into the high idle and smooths out for a bit before it shuts off again. Only during that underlined time does it make that sporadic noise. its like a tap tap....taptaptap....tap...taptap...taptap. No rythem to it at all. At first I thought it could have been a broken spring on the engine dampner (flywheel), but it doesnt do it all at start up. Then i thought it could be a bad cv axle, but it only does it when at idle. So maybe chipped tooth on planetary set?

 

Well, took care of the issue....sold that ***** to Carmax! haha...before it got worse to the point where someone not educated enough would hear the problem. Well...now its their problem. They gave me a decent offer (very top of trade in value at $13,500). I could have gotten more if I sold it myself, but im too guilty and honest of a person to sell someone a car like that. I would never be able to forgive myself lol.

 

So, since selling my hihy to Carmax. I have one 07 hihy that comes to our shop for maintenance with about 100k miles on it. As soon as I got it in the shop I was curious to see if it would exhibit the same noise as mine did. I set it to the ready, and waited for engine idle to go to that high idle after initial start up and listened. Then there it was...heard the same knocking/tapping noise from the e-cvt. The crazy thing is to me is that, why am I the only one that seems to have heard this??? I have tried searching everywhere on the net, and have found no one else at all complaining about it. How can I find two hihy cars with this? lol. There is no way this is normal! Please if there are more of you out there. Try and listen to see if you hihy makes this noise. It mostly does it in neutral or reverse at idle when the engine first starts up after you start it, when its idling and then goes into that higher speed idle, smooths out...thats when you will hear it. Its very noticeable with the door open and have your head out listening for it.

 

I wonder if you are hearing a ticking which might heard due to the use of the Atkinson cycle on the hybrid engines?

 

No way at all. It is definitely coming from underneath the vehicle. It's coming directly from the e-cvt. I put my mech stethoscope to it and it's no doubt where it's coming from. It sounds really close to an engine knock. That hollow knock type sound.I really can't believe I can't find any info on this at all.

 

Interesting, I'll have to try that on mine and see but I've never noticed any major knocking sounds at all.....maybe just a slight tick at start up but smooths right out when warmed up to temp.

 

Yes, when you start it and when the ICE is running and when it levels out to that faster quieter idle before it shuts off is when it happens. Dont listen for anything the rythmatic. Its off beat and very obvious when you put your head in the driverside wheel well or underneath. I would just start it up and stand outside to listen. If you dont hear it in park then try it in neutral or reverse. But the ICE has to be running. Like I said i have heard it on two differnt highlander hybrids. Mine was a 2006 and the other was a 2007. Let me know if you hear anything.