tough, but need help in identifying this sound..

[RF Overlord]

Originally Posted by pepepeter

If there were bumps on the road I could see how that would cause the exhaust or its shielding to rattle, but i dont see how very gentle acceleration would cause it to rattle if it was loose.

Exhaust systems, being similar to organ pipes, can resonate with engine RPM & exhaust flow and cause a lot of weird-o sounds. Not saying this is your problem, just explaining how it's possible.

[pepepeter]

Originally Posted by Carbon

Tappet noise would be a regular ticking with the cause being a hydraulic adjuster not fully doing its job. I think a rattle would be less regular. Does your sound sound like ball bearings bouncing around in the engine? If so, consider trying a couple tanks of high octane gasoline to see if that reduces the sound.

Somewhat does or could sound like that. i did try a full tank of high octane (91) with no improvement at all. I could try 2 tanks next time, although I doubt I will do that without first having a mechanic listen in while I drive.

Originally Posted by Carbon

Does your sound sound tinny or like something more solid generating the sound? Here are some rattle sounds: https://www.youtube.com/watch?v=s8mof1OBGTE https://www.youtube.com/watch?v=2hXpqCVMYhI https://www.youtube.com/watch?v=s8UnuTvElzQ https://www.youtube.com/watch?v=_jk48X85LsM

The sound is not loud enough to be heard in the vehicle, it can only be heard with the windows down and easier to hear when driving near a wall or buildings; sounds bounces off as I mentinoed eariler. However, the last link regarding the catalyic converter almost sounds very similar. Will look into this by simply banging on it to test for loose parts. Thanks.

[pepepeter]

Originally Posted by dandel

My 2011 developed a similar (per your description) noise earlier this summer. My mechanic identified it as a loose baffle inside the muffler. Took it to the Toyota dealer (still under warranty) 4 times before they finally admitted that was the noise. So after 4 visits, they finally changed the muffler...............noise gone.

Oh wow, so you know exactly what I am talking about then.. thank goodness finally another owner that has/had a smiliar experience.

Somewhat concerned given that mine is a 2008, but is under the "extended" warranty. Why did it take so many trips for them to realize/agree the cause of the sound? Oh wait nevermind.. it was the dealership . In between these visits what did they claim was the source of the sound (did they ever admit to hearing it)? Would like to know so i can steer the dealer away from these coming up as reasons for my rav4. I hope its a loose baffle with my rav4. Thanks.

[Noel]

i asked about tappet noise because my tensioner pulley is failing and that is what it sounds like.

[pepepeter]

Originally Posted by Noel

i asked about tappet noise because my tensioner pulley is failing and that is what it sounds like.

so are you saying the sounds of a failing tensioner pulley can be very similar to tappet noise?

I do recall coming across a TSB for the idler pulley and my VIN does fall in the category of AFTER production (calls for replacement of idler pulley only). Is the idler pulley capable of making similar sounds?

[dandel]

Originally Posted by pepepeter

Oh wow, so you know exactly what I am talking about then.. thank goodness finally another owner that has/had a smiliar experience.

Somewhat concerned given that mine is a 2008, but is under the "extended" warranty. Why did it take so many trips for them to realize/agree the cause of the sound? Oh wait nevermind.. it was the dealership . In between these visits what did they claim was the source of the sound (did they ever admit to hearing it)? Would like to know so i can steer the dealer away from these coming up as reasons for my rav4. I hope its a loose baffle with my rav4. Thanks.

I took it to my own (private) mechanic first and he said that it sounded like a loose baffle in the muffler. (He was right.) Then I took it to the dealer (under warranty). They listened and said that it was too "intermittent" and they couldn't pin it down. "Drive it a while and if it still does it, bring it back". Brought it back the sencond time and they rode with me and listened again. "Can't pin it down. We'll talk to the regional technician". Brought it back the third time. "Maybe muffler, maybe not we'll call you back after we drive another Rav4 & listen to that one" (such BS). Finally, the fourth time they could see I was really pi$$ed, and the tech said yea, it sounds like the muffler-we'll order a new one and replace it.